Abstracts of the 4th Coatings and Interfaces Online Conference ^†

1. Conference Introduction

The 4th Coatings and Interfaces Conference (CIC2025) was held online from 21–23 May 2025, and chaired by Dr. Emerson Coy. The impact of coatings and interfaces on various technological advancements is undeniable. From sustainable energy solutions and pollution control to cultural heritage preservation and healthcare innovations, this field is pivotal in addressing critical challenges in society and research. CIC2025 fostered innovative and timely collaborations in the following exciting fields: Plasma Coatings, Surfaces & Interfaces; Laser-Coating Technology: Deposition, Structuring and Cladding; Coatings and Thin Film Deposition; Corrosion, Erosion and the Tribological and Mechanical Aspects of Coatings; Novel Methods/Techniques for Coating Deposition and Characterization; Protective Coatings in Cultural Heritage, Conservation and Preservation; The Biomedical Application of Coatings.

Conference Sessions

• Session 1. Plasma Coatings, Surfaces & Interfaces

Session Chairs:

Prof. Dr. Qi Hua Fan, College of Engineering, Michigan State University, USA;

Dr. Mukul K Dubey, Sardar Patel Renewable Energy Research Institute, Anand, India.

• Session 2. Laser-Coating Technology: Deposition, Structuring and Cladding

Session Chair:

Dr. Rafael Comesaña, Materials Engineering, Applied Mechanics and Construction, University of Vigo, Spain.

• Session 3. Coatings and Thin Film Deposition

Session Chair:

Assoc. Prof. Adrian David, University of Caen, National School of Engineers of Caen, Caen, France.

• Session 4. Corrosion, Erosion and the Tribological and Mechanical Aspects of Coatings

Session Chair:

Prof. Dr. Huirong Le, The Future Lab, Tsinghua University, Beijing, China.

• Session 5. Novel Methods/Techniques for Coating Deposition and Characterization

Session Chairs:

Prof. Dr. Wei Pan, School of Materials Science & Engineering, Tsinghua University, Beijing, China;

Dr. Heping Li, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, China.

• Session 6. Protective Coatings in Cultural Heritage, Conservation and Preservation

Session Chair:

Assoc. Prof. Claudia Pelosi, Università degli Studi della Tuscia Viterbo, Viterbo, Italy.

• Session 7. The Biomedical Application of Coatings

Session Chair:

Dr. Michele Ferrari, Institute of Condensed Matter Chemistry and Technologies for Energy, National Research Council, Genova, Italy.

2. Speakers

2.1. Keynote Speakers

Prof. Dr. Giuseppe Cavallaro, Department of Physics and Chemistry, University of Palermo, Palermo, Italy;

Dr. Antonio Riveiro Rodríguez, University of Vigo, Vigo, Spain;

Prof. Vasileios Koutsos, Institute for Materials and Processes, School of Engineering, The University of Edinburgh, UK;

Prof. Dr. Chi-wai Kan, The Hong Kong Polytechnic University, Hong Kong, China;

Prof. Bocong Zheng, School of Physics, Beijing Institute of Technology, Beijing, China.

2.2. Invited Speakers

Prof. Dr. Kan Zhang, Department of Materials Science, Jilin University, China;

Prof. Dr. Yung-Kang Shen, School of Dental Technology, Taipei Medical University, Taipei, Taiwan;

Dr. Nina Baule, Fraunhofer USA Center Midwest (CMW), East Lansing, MI, USA;

Prof. Claudia Mazzuca, Department of Chemical Science and Technologies, University of Rome “Tor Vergata”, Rome, Italy;

Dr. Florian Pape, Intsitute of Machine Design and Tribolog, Leibniz University Hanover, Germany;

Assoc. Prof. Marie Dallocchio, Research Center for Ions, Materials and Photonics (CIMAP), University of CAEN, France;

Dr. Lucia Iglesias, Laboratoire Albert Fert-CNRS, Thales Université, Paris, France;

Dr. Tabitha A. Amollo, Lecturer, Department of Physics, Egerton University, Kenya; Future Africa Research Leadership Fellow, University of Pretoria, SA; Africa Futures fellow, Michigan State University, USA.

3. Plasma Coatings, Surfaces & Interfaces

3.1. Correlating Hydrophobicity to Surface Chemistry for Low-Frequency Vibration Energy-Harvesting Applications

• Giovanni Carraro ¹, Letizia Savio ¹, Gianangelo Bracco ^1,2, Luca Vattuone ^1,2, Roberto Masini ¹ and Marco Smerieri ¹

¹ 

IMEM-CNR, Via Dodecaneso 33, 16146 Genova, Italy

² 

Dipartimento di Fisica, Università degli Studi di Genova, Via Dodecaneso 33, 16146 Genova, Italy

The relationship between hydrophobicity and surface chemistry is crucial for optimizing materials used in vibration energy harvesting (VEH) applications, where environmental resilience and charge transfer efficiency are essential. Aluminum alloys, commonly used in the automotive, aerospace, and energy sectors, naturally develop an oxide layer that offers limited corrosion resistance in humid and saline environments. A promising strategy to improve performance and durability consists of modifying the wettability of aluminum surfaces.

In this study, we produced highly hydrophobic aluminum surfaces using a one-step etching method, yielding microstructured roughening of the surfaces that facilitates air trapping, enhancing hydrophobic behaviour. Contact Angle Goniometry (CA), Scanning Electron Microscopy (SEM), and X-ray Photoelectron Spectroscopy (XPS) were employed to correlate surface wettability with sub-micrometer-scale morphology and chemical composition. We found that surface hydrophobicity is governed by the interplay between hierarchical micro/nanostructures and the chemical composition of the outermost layers. We used the optimized aluminum surfaces for a portable VEH device, specifically leveraging Reverse Electrowetting on Dielectric (REWoD) technology, that efficiently harvests energy from low-frequency vibrations (10 Hz) typical of human motion. We realized the device using off-the-shelf polyacrylamide (PAAm) hydrogels loaded with saline solutions using a heat treatment that extends the hydrogel drying times significantly. The laboratory prototype generated an average power of ∼1.55 µW at 7 Hz, achieving a power density of 9 nW/µL.

3.2. Deposition, Processing and Functionalization of Vertical Graphene Nanowalls and Their Application on Energy Harvesting and Storage

• Stefanos Chaitoglou, Enric Bertran-Serra and Roger Amade

• University of Barcelona, 08007 Barcelona, Spain

Graphene-based materials exhibit a series of desired properties, e.g., electrical conductivity, high surface-to-volume ratio and tuning of surface chemistry between others, which make them a Swiss army knife for use in energy-related applications. In the present talk, I present the latest experimental results from our research on vertical graphene nanowall (VGNW) use in the above applications. VGNWs are characterized by the perpendicular orientation of graphene nanosheets with respect to the growth substrate, which is advantageous for homogeneous functionalization with other nanoparticles via vapor deposition techniques. I provide insights on the deposition of VGNWs as a coating on planar and three-dimensional nanostructured substrates via plasma chemical vapor deposition [1]. Then, I present results on the processing of VGNWs by laser pulses as a means to tune their crystal structure and control the density of defects [2]. I will conclude the talk showing the results on the preparation of VGNW-based compounds for application in electrocatalytic hydrogen evolution [3–5] and supercapacitor applications [6], focusing on their role as a template for the efficient anchoring of nanostructures.

References

[1] S. Chaitoglou, R. Amade, E. Bertran Applied Surface Science 592 (2022) 153327.

[2] S. Chaitoglou, A. Klini, N. Papakosta, Y. Ma, R. Amade, P. Loukakos, and E. Bertran-Serra J. Phys. Chem. Lett. 15 (2024) 3779–3784.

[3] S. Chaitoglou, R. Ospina, Y. Ma, R. Amade, X. Vendrell, J. Rodriguez-Pereira, E. Bertran-Serra Journal of Alloys and Compounds 972 (2024) 172891.

[4] S. Chaitoglou, R. Amade, R. Ospina, E. Bertran ACS Appl. Energy Mater. 6 (2023) 6120–6131.

[5] S. Rodriguez-Miguel, Y. Ma, G. Farid, R. Amade, R. Ospina, J. Luis Andujar, E. Bertran-Serra, S. Chaitoglou Heliyon 10 (2024) e31230.

[6] Y. Ma, S. Chaitoglou, G. Farid, R. Amade, R. Ospina, A. Munoz-Rosas, E. Bertran-Serra Chemical Engineering Journal 488 (2024) 151135.

3.3. Improvement in the Contact Between TiAlV and Organic Tissue Through TiO_xC_y Organometallic Multilayer Coatings for Improving Osseointegration

• Sandra Rubio and Laurent Houssiau

• Physics Department, University of Namur, Rue Grafé, 2 5000 Namur, Belgium

Titanium alloys like TiAlV are biocompatible materials widely used in dental implants [1]. Hydrophilic surfaces enhance adhesion between the implant screw and tissue, promoting osseointegration and improving success rates through optimized chemical properties [2].

A novel multilayer coating approach is developed to avoid early implant failure by optimizing surface properties. This research focuses on creating innovative TiO_xC_y organometallic multilayer coatings on Ti₉₀Al₆V₄ substrates to improve osseointegration. These coatings are prepared using Plasma-Enhanced Chemical Vapor Deposition (PECVD), varying deposition parameters such as reactive gas flow, power, and time to modify the chemical composition, hydrophilicity, and layer thickness.

Comprehensive characterization of the surface is conducted using X-Ray Photoelectron Spectroscopy (XPS) to determine the chemical environment, and using the contact angle to evaluate wettability. To further understand the chemical composition within each layer, XPS depth profiling analyses are performed.

The preliminary results revealed that a multilayer designed with a decreasing reactive gas flow exhibits a gradient in its composition. Near the substrate, the layers display a mineral-like, low-carbon structure, transitioning to an organic-like, high-carbon composition (with a carbon percentage 3 times higher) at the outermost surface. This outer layer, engineered to interact with organic tissue, has a higher hydrophilic surface, resulting in superior osseointegration.

This innovative multilayer design not only represents a significant advancement in dental implant technology but also sets a precedent for the development of functional coatings for biomedical applications.

References

[1] Marin, E., & Lanzutti, A. (2023). Biomedical applications of titanium alloys: a comprehensive review. Materials, 17(1), 114.

[2] Gittens, R. A., Scheideler, L., Rupp, F., Hyzy, S. L., Geis-Gerstorfer, J., Schwartz, Z., & Boyan, B. D. (2014). A review on the wettability of dental implant surfaces II: Biological and clinical aspects. Acta biomaterialia, 10(7), 2907–2918.

3.4. Infrared Thermography of Thermal Spray Coating Processes as Quality Monitoring Tool

• Thomas Lindner, Sahib Kaur, Maximilian Grimm, Kay Schlegel and Thomas Lampke

• Materials and Surface Engineering, Institute of Materials Science and Engineering, Chemnitz University of Technology, 09107 Chemnitz, Germany

The evolution of substrate surface temperature during coating deposition is a decisive property-determining factor in thermal spraying. Local heat development is influenced by various factors such as thermal conductivity and substrate thickness. High fluctuations in surface temperatures promote the formation of residual stresses in the coating layers during cooling. Therefore, the risk of oxidation, cracking, or delamination increases. Therefore, limiting the surface temperature appears beneficial for quality assurance. Infrared (IR) thermography offers the possibility to determine the surface temperature in the coating process without contact. Determining factors in temperature evolution during the thermal spray process were identified by using IR thermography. The interaction between the substrate and coating material was taken into account. Furthermore, application limits for IR thermography (Optris XI80) in comparison to thermocouple measurements for the temperature range of 0–250 °C were determined. For this purpose, the stainless steel AISI 316L was coated on aluminum and steel sheets by atmospheric plasma spraying (APS). The influence of substrate thickness was evaluated. A correlation between the temperature history during the coating process and the corrosion properties was established. Current density potential measurements using gel electrolytes were used for this purpose. Clear correlations between the development of the surface temperature and the resulting coating properties were derived.

3.5. Non-Thermal Plasma (NTP) for Continuous H₂O₂ Production from Water and Oxygen

• Niwesh Ojha

• Indian Institute of Technology Roorkee, Roorkee, Uttarakhand 247667, India

Conventional methods for hydrogen peroxide (H₂O₂) synthesis, such as heterogeneous catalytic processes, require hydrogen (H₂) and oxygen (O₂) as feedstocks, along with expensive noble metals and organic solvents. These methods are energy-intensive and hazardous. In contrast, non-thermal plasma (NTP) generated within a dielectric barrier discharge (DBD) coaxial reactor provides 1 to 10 eV energy, sufficient to even drive thermodynamically unfavorable reactions by breaking molecular bonds. This study investigates the direct synthesis of aqueous H₂O₂ by passing oxygen through varying flow rates in a non-thermal plasma reactor. The outlet gas from the plasma reactor is then bubbled into water, facilitating H₂O₂ production. This method relies solely on water, oxygen, gas, and electricity, offering an environmentally friendly alternative to traditional processes.

This study also explores the role of a water–ethanol solution in enhancing product yield by approximately 10 times in the continuous production of concentrated aqueous hydrogen peroxide (H₂O₂). Experiments were initially conducted without catalysts, and the impact of various gas flow rates, plasma power, and residence time on conversion efficiency was examined. Electron Spin Resonance (ESR) studies indicate that oxygen radicals play a crucial role in the selective production of H₂O₂. Our findings present a proof-of-concept for utilizing low-cost aluminum electrodes in a dielectric barrier discharge (DBD) reactor, relying solely on electricity, water, and dioxygen for the generation of H₂O₂. This ongoing process ensures continuous improvement and provides the scalability needed to achieve high technology readiness levels.

3.6. Particle–Plasma Interactions: Particle Melting State and Its Impact on the Phase Composition and Deposition Efficiency in Atmospheric Plasma-Sprayed Alumina Coatings

• Maximilian Grimm, Thomas Lindner and Thomas Lampke

• University of Technology Chemnitz, Group of Materials und Surface Engineering

Plasma–particle interactions strongly influence the formation of atmospheric plasma-sprayed (APS) coatings. Especially for alumina, which usually undergoes a complex phase transformation of α-Al₂O₃ to metastable phases such as γ-, η- or δ-Al₂O₃ during thermal spraying, the heating and cooling behavior of the particles is of great importance.

This study therefore investigates the effect of plasma fluctuation and particle morphology on the melting behavior of aluminia and alumina-based powder particles. In particular, the impact of the degree of particle melting on the known phase transformation and the deposition efficiency is being investigated. In addition to the phase analysis of the coatings, powders collected during the spraying process were examined to evaluate their changes in the plasma. The particle morphology of the powders collected provides clear indications of their degree of melting. Moreover, both the plasma fluctuations and important particle parameters, such as particle temperature and velocity, are recorded.

The results show that the degree of particle melting in strongly linked to the plasma fluctuations, which can be significantly influenced by adjusting the process parameters. While higher α-Al₂O₃ contents in the collected powder cannot be transferred into the coating if they are attributed to non-melted particles, coatings with higher α-Al₂O₃ contents can be achieved by partially melted particles or the use of Al₂O₃-based solid solutions without negatively affecting the deposition efficiency.

3.7. Room-Temperature Hydrogen Absorption in Mg-Based Thin Films

• Lesław Smardz

• Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, 60-179 Poznań, Poland

The growing interest in the study of reversibly hydrogen-absorbing thin films is mainly due to their potential application as hydrogen sensors or switchable mirrors (smart windows) in electronics. From an economic point of view, magnesium would be the most suitable material for such applications. In contrast to bulk magnesium, Mg thin films covered with a palladium layer can absorb hydrogen at room temperature and pressures of up to 1 bar. One important experimental problem that still needs to be solved is the improvement of the too-slow absorption kinetics. This paper presents the results of studies leading to a significant improvement in hydrogen absorption kinetics by depositing an ultrathin Ni (Al or C) layer between the top Pd catalytic layer and the Mg base layer. A significant improvement in the absorption kinetics was also achieved by replacing pure Mg with a Mg₂Ni alloy. In addition, in order to determine the mechanisms responsible for the improvement of absorption kinetics, the effect of atom mixing in the interface region was studied in detail using X-ray photoelectron spectroscopy. The obtained results confirmed the important role of the Ni interlayer in improving hydrogen absorption kinetics in Pd/Ni/Mg trilayers. In Pd/Mg₂Ni bilayers, the Ni interlayer is formed spontaneously due to the segregation of Mg atoms on the surface. In the case of Al and C interlayers, the improvement of absorption kinetics occurs due to the spontaneous formation of small islands in the interface region containing Al atoms and magnesium carbide, respectively, which can form heterogeneous nucleation centres. The optimal thicknesses of Ni, Al and C layers are 3.0, 0.5, and 1.4 nm, respectively. The obtained results can be used to obtain new thin-film metallic nanomaterials with improved functional properties at room temperature.

4. Laser-Coating Technology: Deposition, Structuring and Cladding

4.1. High-Power Laser Surface Structuring of Bioactive Glasses: Recent Advances and Perspectives

• Mario González-Quintas ¹, Bruno Gago-Vidal ^1,2, Erik Calvo-García ¹, Hamza Sajjad ¹, Rafael Comesaña ¹, Juan Pou ¹ and Antonio Riveiro ¹

¹ 

CINTECX, LaserON Research Group, Universidade de Vigo, 36310 Vigo, Spain

² 

Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, 36312 Vigo, Spain

Introduction: Bioactive glasses are a type of biomaterial widely used when high osteoconductive or osteosynthesis capabilities are required. In recent years, research on bioactive glasses has been partially directed towards obtaining more stable compositions with increased network connectivity. Thus, it is possible to use this biomaterial in diverse applications with high surface/volume ratios, such as scaffolds, in which the most reactive bioactive glasses experience excessively rapid dissolution. The micro-structuring of the surface of these biomaterials is a research niche that has been scarcely explored, mainly because the osteoconductivity mechanism that occurs during the interaction with biological fluids is associated with the dissolution of the glass surface layer. However, it has recently been shown that surface modification by laser can produce permanent long-term surface changes.

Methods: For this work, recent reports in the field of laser surface modification of bioactive glass have been critically studied and analysed. In addition, laboratory experiments have been carried out on the structuring of the surface of glasses with different network connectivities. The in vitro behaviour when in contact with simulated physiological fluid has been characterised.

Results and Conclusions: In this work, the latest advances in laser surface modification of bioactive glasses are presented, discussing the different types of lasers used and the radiation–matter interaction phenomena, particularly in terms of surface energy density and interaction times. Furthermore, the properties of the micro-structured surfaces are presented as a function of the parameters of the laser surface modification process and their evolution when they are subjected to contact with simulated physiological fluids.

The in vitro behavior of the laser-modified bioactive glass surface demonstrates that, by selecting the appropriate laser radiation and the appropriate process conditions, it is possible to produce a selective change in the osteoconductivity process.

4.2. Illuminating Surfaces: Emerging Trends in Laser Surface Texturing Applications

• Antonio Riveiro Rodriguez ^1,2, Pablo Pou-Álvarez ¹, Mario González-Quintas ¹, Bruno Gago-Vidal ¹, Mónica Fernandez-Arias ¹, Jesús del Val ¹, Aida Badaoui Fernández ² and Juan Pou ¹

¹ 

CINTECX, LaserON Research Group, Universidade de Vigo, 36310 Vigo, Spain

² 

Materials Engineering, Applied Mechanics and Construction Department, E.E.I., University of Vigo, Lagoas-Marcosende, 36310 Vigo, Spain

Surface functionalization plays a crucial role in advancing material performance across various industries, enabling tailored properties such as enhanced tribological behavior, improved wettability, increased adhesion, better biocompatibility, and superior optical characteristics. As demand grows for precise and efficient surface modification techniques, laser surface texturing (LST) has emerged as a promising technology due to its high precision, repeatability, productivity, and ability to create micro- and even nanoscale surface features with minimal material waste. Unlike conventional methods, LST offers a non-contact, environmentally friendly approach (as chemicals can be avoided) that allows for the localized and controlled modification of the surface topography and even chemistry, thereby optimizing the performance in applications ranging from biomedical implants to energy storage systems.

This communication explores the latest advancements in laser surface texturing, highlighting novel and emerging trends. These key developments include, among others, the production of extreme wetting surfaces (superhydrophilic or superhydrophobic), the production of self-cleaning surfaces, the potential of laser surface texturing to produce superior biomedical surfaces, and the application of laser surface texturing to control the corrosion behavior of biomaterials. By illuminating these evolving trends, this study aims at providing insights into the future potential of laser surface texturing as a transformative tool for next-generation functional surfaces.

4.3. Superhydrophobic Aluminium Surface Obtained via Laser Structuring and Stearic Acid Grafting with Corrosion Protection and Anti-Icing Abilities

• Nina Kovač ^1,2, Matic Može ³, Barbara Kapun ¹, Iztok Golobič ³, Ingrid Milošev ¹ and Peter Rodič ¹

¹ 

Jožef Stefan Institute, Department of Physical and Organic Chemistry, Jamova c. 39, 1000 Ljubljana, Slovenia

² 

Jožef Stefan International Postgraduate School, 1000 Ljubljana, Jamova c. 39, Slovenia

³ 

University of Ljubljana, Faculty of Mechanical Engineering, Aškerčeva c. 6, 1000 Ljubljana, Slovenia

Aluminium and its alloys are widely used in the automotive, aerospace, and marine industries due to their excellent mechanical properties and corrosion resistance. However, their susceptibility to corrosion in chloride-rich environments necessitates effective protection strategies. One promising approach is the development of superhydrophobic surfaces, which exhibit extreme water repellency (contact angle > 150°) by combining hierarchical surface structures with low-surface-energy materials [1,2].

This study aimed to enhance corrosion resistance and anti-icing properties by integrating laser surface structuring with stearic acid grafting. Different laser structuring parameters (selected scanning line spacings) were explored to optimize surface roughness before applying a stearic acid coating. Surface morphology, wettability, and roughness were analyzed using scanning electron microscopy, a contact profilometer, and a goniometer. Corrosion resistance was evaluated via electrochemical testing in 0.1 M NaCl, while the anti-icing effect and droplet-bouncing behaviour were assessed.

Results demonstrated that the optimal laser parameter (scanning line spacing) combined with stearic acid grafting significantly improved corrosion resistance and water repellency. This method offers a cost-effective, scalable approach for enhancing aluminium surfaces, making it suitable for applications requiring improved durability and anti-icing performance.

References:

[1] A. Bahgat Radwan, A.M. Abdullah, N.A. Alnuaimi, Recent advances in corrosion resistant superhydrophobic coatings, Corros. Rev. 36 (2018) 127–153. https://doi.org/10.1515/corrrev-2017-0012.

[2] P. Rodič, N. Kovač, S. Kralj, S. Jereb, I. Golobič, M. Može, I. Milošev, Anti-corrosion and anti-icing properties of superhydrophobic laser-textured aluminum surfaces, Surf. Coat. Technol. 494 (2024) 131325. https://doi.org/10.1016/j.surfcoat.2024.131325.

Acknowledgements: The financial support from the Slovenian Research and Innovation Agency (ARIS) research core funding No. P2-0393, P1-0134, and P2-0223, and through the ARIS project, L2-60141, is acknowledged.

5. Coatings and Thin Film Deposition

5.1. Assessment of the Inhibitive Effect of Papaya (Carica papaya) Leaf Extract from Ultrasound–Microwave-Assisted Extraction (UMAE) on the Corrosion of Mild Steel

• Arbee Chrystel V. Alera, Alexandria D. Bernardo, Rosemary P. Cole, James Gabriel G. Galano, Jozel T. Valenzuela and Rugi Vicente C. Rubi

¹ 

Chemical Engineering Department, College of Engineering, Adamson University, 900 San Marcelino St. Ermita, Manila 1002, Philippines

² 

Adamson University Laboratory for Biomass, Energy and Nanotechnology (ALBEN), 900 San Marcelino St. Ermita, Manila 1000, Philippines

Corrosion poses significant challenges to metals used in construction and machinery. This study evaluated the inhibitive effect of papaya (Carica papaya) leaf extract, obtained through Ultrasound–Microwave-Assisted Extraction (UMAE), as an eco-friendly corrosion inhibitor for mild steel. Papaya (Carica papaya) leaves are rich in phytochemicals such as alkaloids, flavonoids, tannins, and saponins, which form protective layers on metal surfaces and reduce degradation. UMAE, combining ultrasonic and microwave-assisted extraction, proved more efficient than conventional Soxhlet extraction, yielding 63.43% compared to 6.78%, while preserving bioactive compounds. Papaya (Carica papaya) leaf extract (PLE)-coated mild steel (MS) strips were immersed in hydrochloric acid (HCl) solutions (0.5 M, 1 M, 1.5 M) and monitored over various exposure times. Weight loss, corrosion rates, and inhibition efficiency were measured, with the lowest weight loss of 2.1798 g under four coatings of PLE after 336 h and a peak efficiency of 97.63%. Characterization techniques such as SEM-EDX, FTIR, and UV-Vis confirmed the formation of corrosion-resistant barriers and identified key functional groups responsible for the PLE’s protective properties. Statistical analysis using ANOVA revealed that PLE has a significant relationship with inhibition efficiency, with an F-value of 13.69035, p-value of 0.001638, and F crit less than the F-value. These findings position PLE as a promising, sustainable solution for corrosion prevention in industrial applications.

5.2. Bio-Based, Sustainable, Green, and UV-Curable Polymer Formulations for Coating Applications

• Nana Khandu Satpute and Vasi Shaikh

• Department of Chemical Engineering, Dr. Vishwanath Karad MIT World Peace University, Kothrud, Pune, India-411038

The goal of bio-based, sustainable, and green coating formulations is to replace conventional petrochemical-based materials, thereby reducing VOC emissions and dependence on non-renewable resources. The present research focuses on the synthesis and characterization of UV-curable, bio-based, sustainable, green coating formulations derived from plant oils and other sustainable feedstock. This system uses bio-based epoxidized soybean oil (ESBO) and itaconic acid as major renewable precursors. We prepared the resin by ring-opening of ESBO with polyol, involving an etherification reaction and finally esterification with a bio-based acid. The progress of the reaction was monitored by the oxirane oxygen content (OOC) and acid value. Several formulations were attempted by varying the ratio of oil and polyol. The resin thus prepared was used for coating formulations by varying percentages of the photoinitiator and reactive diluents. Thus, the prepared formulations were applied to the substrate and cured by exposure to the UV radiation source.

The cured films on the substrate were investigated for mechanical and chemical properties. Properties such as scratch hardness, pencil hardness, adhesion, gel content, solvent rub resistance, and gloss were studied. The chemical changes during the reaction and after curing were confirmed by FTIR. The increased renewable content (above 70%) and non-volatile matter in the coating formulations demonstrate their sustainability and green nature. The mechanical properties were observed to be on par with the traditional petroleum-based coatings, showing their enormous potential in UV-curable coating applications. This work demonstrates that incorporating bio-based components into UV-curable systems can produce high-performance, sustainable coatings that contribute to environmental conservation and resource efficiency. This advancement contributes to the development of greener coating technologies that align with global sustainability goals.

5.3. Biobased and Home-Compostable Blend Films and Layers for Protecting Perishable Foods

• Maria-Beatrice Coltelli, Luca Panariello, Vito Gigante and Andrea Lazzeri

• Department of Civil and Industrial Engineering, University of Pisa, 56126 Pisa, Italy

Biobased and home-compostable films were produced by blending poly (lactic acid) (PLA) and poly (butylene succinate-co-adipate) (PBSA). These films, which can be applied on different substrates by exploiting their thermoplastic feature, were found to be easily recyclable in an industrial environment. The composition of PLA/PBSA blends, produced using a mini-extruder, was varied to identify the films with the best barrier properties for perishable liquid foods, such as whey. The weight of the whey contained in the sealed film was measured over time. The blends were also evaluated for their mechanical and melt fluidity properties, as well as their surface composition, using infrared spectroscopy. The results demonstrated that the composition of the blends significantly influenced the barrier properties of the films.

These findings are not only applicable to dairy products but also hold potential for packaging perishable fruits, which are abundant in the Mediterranean region. Fruits such as strawberries, dates, and tangerines could benefit from this innovative packaging solution. The high availability of these fruits in the Mediterranean area makes the hereby proposed application particularly relevant. The development of such films could contribute to reducing food waste and improving the shelf life of perishable goods, thereby offering a sustainable and practical packaging alternative. This research highlights the importance of material composition in designing effective and environmentally friendly packaging solutions.

5.4. Comparison of Wear Resistance and Biological Properties of Ag/W_1−xTi_xB_2,5 Nanocomposite and Pure-Silver Coating

• Katarzyna Zielińska and Tomasz Mościcki

• Institute of Fundamental Technological Research, Polish Academy of Sciences, Pawinskiego 5B, 02-106 Warsaw, Poland

Transition-metal borides have exceptional mechanical properties, such as high hardness and fracture toughness. They also have high thermal and chemical stability. Silver, on the other hand, is an attractive material for antibacterial applications due to its biological properties. Combining these materials can make it possible to produce super-hard coatings with antibacterial properties that are also wear-resistant, even under extreme temperature conditions.

In this work, Ag/W_0.84Ti_0.16B_2.5 nanocomposite layers were deposited, comparing their properties with a film made of pure silver. The silver film was produced by pulsed laser deposition (PLD), while the titanium-doped tungsten boride layer was synthesized by high-power pulsed magnetron sputtering (HiPIMS). The structure and chemical composition of the films were characterized by scanning electron microscopy (SEM) and X-ray energy spectroscopy (EDS). The silver particles were uniformly covered with a coating of borides. The surface roughness of the composite was about 100 nm (Ra) and was much higher than the roughness of the layer consisting only of metal borides.

Mechanical properties such as hardness were tested using The Micro Combi Tester MCT3, while wear resistance was verified by abrasion under a reciprocating motion. The silver layer can favorably affect mechanical properties by improving the material’s ductility and tribological properties, at the expense of lowering hardness. Biological tests were carried out in a liquid suspension of Staphylococcus Aureus bacteria (a Gram-positive bacterium). Incubation was carried out for 20 h in a greenhouse at 37 °C. Unfortunately, from the studies so far, the composite has not been found to show antibacterial properties in the classic suspension test.

5.5. Crystal Structure of Filled Single-Walled Carbon Nanotubes for Coatings

• Marianna V. Kharlamova

• Lomonosov Moscow State University, Leninskie Gory 1, Russia

Single-walled carbon nanotubes (SWCNTs) with different properties are prepared for applications. The control of the structure of the SWCNTs is important. The analysis of the structure of the pristine and functionalized SWCNTs is needed for biosensor applications. The investigation of the characteristics of the crystal structure of the substances encapsulated inside SWCNTs opens ways to revealing the parameters of the structure. The diameters of the SWCNTs are chosen precisely, and crystal structures are modified for particular applications. It becomes possible to tailor the crystal structure of the compounds in the SWCNTs with different metallicities, diameters, and numbers of walls. The aim of this work is the investigation of the crystal structure in the SWCNTs and modified SWCNTs, and the analysis of the electronic features in modified SWCNTs. The crystal structure of silver chloride inside the SWCNTs with a metallicity-mixed and semiconducting conductivity type was investigated. New one-dimensional structures were obtained inside the SWCNTs with a diameter of 1.4 nm, as revealed by scanning transmission electron microscopy (STEM). The analysis of the electronic features of filled SWCNTs gives information on doping. Raman spectroscopy showed modified electronic properties of the filled metallicity-mixed and semiconducting SWCNTs. Doping was observed in the filled SWCNTs. These data are useful for biosensor applications of filled SWCNTs.

5.6. Deposited Thin-Film Nanoelectrocatalysts of Non-Noble Metals for Co-Capture of CO₂ and Reduction of Nitrates

• Irina Kuznetsova, Dmitry Kultin, Olga Lebedeva and Leonid Kustov

¹ 

Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia

² 

N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, Moscow 119991, Russia

Introduction: The co-electrolysis of nitrate and CO₂ can contribute to urea production with low carbon-oxide emission rate, and at the same time can reduce NO₃⁻ to extremely low permissible concentrations. The synthesis of thin-layer nanoelectrocatalysts containing transition-metal nanoparticles is a promising venture. The study proposes the use of precipitated electrocatalysts from base metals. Such a method makes it possible to obtain an electrocatalyst selective to the reduction reaction of CO₂ or NO₃⁻, and their joint reduction product is urea. The electrocatalyst coating should firmly bind C-N, and can proceed with the formation of intermediate compounds (such as *CONH₂) and others.

Experimental: The materials for the electrocatalyst were synthesized by the authors, and characterized using the methods of SEM, XPS, and DRS. The electrochemical methods of voltammetry, chronoamperometry, electrochemical double-layer capacity, and electrochemical impedance spectroscopy were used in this work.

Results and Discussion: In this study, a selective thin-layer electrocatalyst is to be synthesized and used for the reaction of CO₂ and NO₃⁻ binding and their conversion to urea. The reaction will be carried out using electrochemical reduction under galvanostatic and potentiostatic conditions. As a result, the rate of synthesis of the target product will be determined and the Faraday efficiency of the process will be calculated. The unique electronic structure of transition metals allows them to be active catalysts in the co-reduction reaction of nitrate and carbon dioxide. The choice of metal or different combinations of components in bimetallic catalysts, as well as exploring the conditions of electrochemical synthesis, may allow us to improve the kinetics of the process and increase the selectivity of the process.

Acknowledgment: The authors acknowledge support from Lomonosov Moscow State University Program of Development for providing access to the EIS facilities. The authors express their acknowledgements to the Russian National Research Project No. AAAAA-A21–122040600057–3.

5.7. Deposition Enhanced by Coacervation in Mixtures of Chitosan and a Non-Ionic Sugar-Based Surfactant

• Ana Puente-Santamaría, Josselyn N. Molina-Basurto, Francisco Ortega, Ramón G. Rubio and Eduardo Guzmán

¹ 

Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Madrid (Spain)

² 

Instituto Pluridisciplinar, Universidad Complutense de Madrid, Madrid (Spain)

This study investigates the use of chitosan-alkyl polyglucoside (APG) mixtures as environmentally friendly ingredients in 2-in-1 shampoo formulations. For this purpose, experiments were performed by varying the surfactant concentration and ionic strength at a fixed chitosan concentration. The results show that chitosan–APG mixtures exhibit a phase diagram strongly influenced by APG concentration. At constant chitosan concentration, two different types of regions emerge: one characterized by the formation of transparent mixtures at low and high surfactant concentrations, and another with turbid mixtures at intermediate concentrations where no macroscopic phase separation was observed. These turbid mixtures result from a coacervation process that is critical for the formation of conditioning deposits. The ionic strength affects the phase transition, causing shifts from transparent mixtures to coacervates and back at lower APG concentrations, although the overall phase behavior remained qualitatively similar. Chitosan–APG mixtures promote the formation of conditioning deposits via coacervate deposition. When the system reached the coacervation region, deposition increased significantly regardless of ionic strength. This finding is critical to the development of effective hair care products and demonstrates the potential of these mixtures to provide conditioning benefits comparable to traditional formulations. In summary, this research enhances the development of sustainable and natural cosmetics while addressing key scientific questions about biopolymer behavior under varying conditions.

5.8. Elastic Properties and Moisture Response of Polydopamine Films and Multilayers

• Zuzanna Kaczmarska ¹, Adam Krysztofik ¹, Mikołaj Pochylski ¹, Marcel Boecker ², Christopher V. Synatschke ², Tanja Weil ² and Bartłomiej Graczykowski ¹

¹ 

Faculty of Physics, Adam Mickiewicz University, Uniwersytetu Poznańskiego 2, 61-614 Poznań, Poland

² 

Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany

Polydopamine (PDA) has the rare ability to attach to surfaces traditionally resistant to adhesion, making it a promising candidate for use as a coating. Membranes approximately 20 nm thick PDA were synthesized using cyclical voltammetry electropolymerization and used to produce four examined samples, comprising subsequently higher numbers of PDA stacked layers (from 1 to 4). The stacking of the membranes resulted in a few layered membranes with thicknesses of approximately 20–60 nm. Brillouin light scattering spectroscopy was utilized to investigate the samples’ Young moduli and residual stress, determining their mechanical properties through the dispersion of GHz acoustic phonons. The samples exhibited substantial magnitudes of Young modulus, higher than for classical polymers, with the higher values retained in multilayer samples.

The freestanding PDA membranes’ responses to varying concentrations of water vapor in the air wereobserved under an optical microscope for all samples. The experiments showed a reversible wrinkling/flattening of the membranes at different relative humidity values. A similar response to laser light, attributed to heat-induced water desorption, was investigated by a home-built setup that allowed for stroboscopic imaging of the membrane morphology with temporal resolution. The process was characterized by relaxation times, attributed to parts of the experiment when the laser light was turned on (flat) and off (wrinkled). The obtained actuation times indicate that the ultrathin membranes react to red laser light in millisecond timeframes, with the multilayer samples having longer relaxation times that remained within the same order of magnitude.

Acknowledgments: Z. K., A. K., M. P., and B. G. acknowledge the National Science Centre of Poland (NCN) for the OPUS grant UMO-2021/41/B/ST5/03038.

References

A. Krysztofik, M. Warżajtis, M. Pochylski, M. Boecker, J. Yu, T. Marchesi D’Alvise, P. Puła, P. W. Majewski, Ch. V. Synatschke, T. Weil and B. Graczykowski, Multi-responsive poly-catecholamine nanomembranes, Nanoscale 16, 16227–16237 (2024), https://doi.org/10.1039/D4NR01050G.

5.9. Electrochemical Water Splitting over Heterostructure of Titania Nanotubes and Ni Encapsulated Within MXenes

• Dujearic-Stephane Kouao ¹, Justyna Gumieniak ², Agnieszka Kramek ² and Katarzyna Siuzdak ¹

¹ 

Centre for Plasma and Laser Engineering, The Szewalski Institute of Fluid-Flow Machinery, Polish Academy of Sciences, Fiszera 14 st., 80-231 Gdańsk, Poland

² 

The Faculty of Mechanics and Technology, Rzeszów University of Technology, Kwiatkowskiego 4 St., 37-450 Stalowa Wola, Poland

Introduction: MAX phases are stacked layers of ternary carbides composed of a transition metal, an A-group element, and carbon/or nitrogen. MXenes are a class of materials produced through selective etching of the A-group element within their corresponding MAX phases parents. The traditional etching method for the synthesis of MXenes involves the use of hazardous substances and highly corrosive chemicals, namely the fluorine-based salts. As an alternative, MXenes can be also produced by an electrochemical etching method. One of the main advantages of this method is the use of salts with moderate toxicity and the ability to control the entire etching process by adjusting the applied potential. In this work, an electrochemical method was explored for the production of Ti₃C₂Tx MXene.

Methods: First, Ti₃C₂Tx was synthesized by the electrochemical etching of Ti₃AlC₂ in an electrolyte containing choline chloride and tetrafluoroboric acid at different applied voltages. Then, a heterojunction was fabricated by the drop casting of the synthesized Ti₃C₂Tx, previously modified with Ni, on titania nanotubes (Ni-MXene-TiO₂) and underwent rapid thermal treatment in a hydrogen atmosphere (h-Ni-MXene-TiO₂).

Results: The recorded Raman spectra indicate that the MXene structure can be obtained after 8 h of bipolar etching. However, the yield of the produced MXene decreases significantly with increases in the applied voltage. The SEM images showed that the accordion structure of Ti₃C₂Tx appears when a voltage of 1 V is applied between the electrodes for 16 h.

This material has been selected for further characterization by X-ray photoelectron spectroscopy and X-ray diffraction. In addition, the electrochemical characterization shows much improved activity for the fabricated h-Ni-MXene-TiO₂ regarding water splitting compared to its Ni-MXene-TiO₂ counterparts.

Conclusion: This study presents a facile approach for the synthesis of MXenes and paves the way for the use of h-Ni-MXene-TiO₂, as a promising catalyst for the water-splitting process.

5.10. Electrodeposition of Nickel-Based Thin-Layered Double Hydroxide Electrocatalyst for 2,5-Diformylfuran Production

• Nadia Mumtazah ¹, Nurfadlih Syahlani ², Muhammad Ibadurrohman ¹ and Mohammad Nasikin ¹

¹ 

Department of Chemical Engineering, Faculty of Engineering, Universitas Indonesia, Depok, West Java 16424, Indonesia

² 

Center for Technology Services (Pusyantek), National Research and Innovation Agency, South Tangerang, Banten 15314, Indonesia

The 2,5-diformylfuran (DFF) is a significant biomass derivative that is employed in a variety of industries. One approach is to synthesize it by an oxidation process of 5-hydroxymethylfurfural (HMF). The challenges in DFF manufacture come from the necessity for extreme conditions, the overoxidation issue, and the limitations of noble materials employed in neutral or acidic environments. By using mild alkaline as an electrolyte, DFF can be produced electrochemically alongside hydrogen gas generation, eliminating extreme conditions and allowing for the study of a wide range of transition metals. Moreover, the performance of bimetallic electrocatalysts has been studied, and it has been found to be more active in many kinds of processes, particularly Layered Double Hydroxides (LDHs). Electrodeposition, once widely chosen among various LDH production methods, is preferred for producing controlled and uniform thin layers. This work examines the electrocatalytic properties of NiCo-LDH and NiFe-LDH in the production of DFF. Cobalt, which has a high adsorption characteristic, is compared to iron, which has a weak adsorption characteristic towards HMF. This study demonstrates that NiCo-LDH has a higher activity but lower DFF selectivity compared to NiFe-LDH for the same amount of passed charge. Strong adsorption promotes reactant activation and reduces the energy barrier while reducing DFF selectivity due to overoxidation. To achieve optimal electrocatalyst performance, a careful balance of adsorption strength and reaction pathway management is required. Proper optimization of these parameters is required to improve efficiency and selectivity in the electrocatalytic process.

5.11. Enhancing Architectural Coatings Through Nanotechnology for Better Performance and Reduced Environmental Impact

• Kachana Kasulu and Olga Volichenko

• Department of Architecture, Restoration and Design, Engineering Academy, People’s Friendship University of Russia, Moscow, Russia

Introduction: Architectural coatings are crucial in contemporary eco-friendly design, as they protect the appearance of buildings, extend their service life, and enhance aesthetic appeal. However, traditional formulations often contain volatile organic compounds (VOCs) and other harmful chemicals. The field of nanotechnology offers an innovative approach to improve coating efficiency while minimising environmental impact. This study focuses on the development and application of nano-enhanced coatings, particularly those which are self-cleaning, antimicrobial, and heat-reflective. Additionally, it assesses their potential effects on the maintenance and operation of the structure by increasing durability and reducing resource consumption.

Methods: Our research concentrated on synthesising and characterising nanocomposites derived from silicon dioxide, titanium dioxide, and silver nanoparticles, which were integrated into both water- and solvent-based polymer matrices. The samples were subjected to laboratory evaluations that simulated real-world conditions, including UV exposure, thermal cycling, and prevalent microbial challenges. Performance metrics such as surface hydrophobicity, microbial inhibition, and thermal reflection coefficients were quantified through agar diffusion analysis and infrared spectroscopy.

Results: Preliminary results indicate that nano-enhanced coatings offer significant operational advantages compared to traditional systems. Self-cleaning formulations exhibit enhanced water-repellent properties, which reduce dirt accumulation and decrease cleaning intervals. Antimicrobial coatings have effectively decreased bacterial proliferation and biofilm formation, as demonstrated by standardised testing parameters. Furthermore, heat-reflecting options show reduced heat absorption, minimising cooling requirements in controlled simulations.

Conclusions: Using nanotechnology, architectural coatings can achieve excellent multifunctional performance while reducing resource consumption and pollutant emissions. The widespread use of nano-enhanced coatings can significantly improve the environmental friendliness and cost-effectiveness of buildings and structures that do not require special care.

5.12. Enhancing Colour and Performance of Black Double-Layered Nickel Coatings

• Gabriel Santos ¹, Susana Devesa ¹, Diogo Cavaleiro ¹, Pedro Santos ², Albano Cavaleiro ¹ and Sandra Carvalho ¹

¹ 

University of Coimbra, CEMMPRE, ARISE, Department of Mechanical Engineering, Rua Luís Reis Santos, 3030-788 Coimbra, Portugal

² 

SRAMPORT Lda., Rua António Sérgio 15, 3025-041 Coimbra, Portugal

Coatings are undeniable cornerstones of the industry. This technology serves a variety of different purposes, ranging from functional coatings to protective and/or decorative ones. Indeed, a plethora of coating deposition techniques may be described, specifically low-cost, resourceful and practical ones like electrodeposition, that also benefit from its scale-up potential and production feasibility. Electrodeposition techniques are regularly under scrutiny for environmental reasons, yet their relevance and pertinence continue to endure. In this context, numerous efforts are being made to simplify electrolytes, which might influence the nature of chemical waste and the complexity of subsequent treatments. In this study, electrolytes were composed of a limited number of compounds. In line with this, replacing the common but challenging chromium-based electrolytes was also under consideration, with strong alternatives like nickel-based ones emerging. Therefore, the main target of the present work was the achievement of electrodeposited double-layered nickel coatings, specifically dull-nickel pre-coatings followed by black nickel coatings, deposited onto steel substrates. This study highlighted colour quality and decorative potential, as well as the possible enhancement of mechanical properties, such as the coefficient of friction. Additionally, the effect of substrate immersion in HCl for surface activation was also evaluated and adjusted. As a result, the pre-coating characterisation was established. The Scanning Electron Microscope (SEM) analysis unveiled a homogeneous surface and a medium superficial feature of 2.56 µm. As well, the Energy-Dispersive X-ray Spectroscopy (EDS) and X-ray Diffraction (XRD) investigations disclosed the high content of Ni and its crystallinity, respectively. As for the black coatings, the XRD analysis confirmed an amorphous structure. In particular, sample BL10, which corresponds to the black nickel coating deposited for 10 min, demonstrated optimal outcomes in terms of colour and roughness, achieving the lowest brightness (L*) value and the least heterogeneous roughness.

5.13. Experimental Investigation of the Optoelectronic Properties of Carbazole-Based Hole Transport Layers for Photovoltaic Applications

• Najla El Aallaoui ¹, Benyounes Oukarfi ¹, Mimoun Zazoui ¹ and Anna Zawadzka ²

¹ 

Laboratory of Materials, Energy and Control System, Faculty of Sciences and Technology, Hassan II University of Casablanca, Mohammedia, Morocco

² 

Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziądzka Torun, Poland

Perovskite solar cells (PSCs) have emerged as a groundbreaking photovoltaic technology, achieving power conversion efficiencies exceeding 25% with the integration of organic small-molecule hole transport materials (HTMs). Despite this significant advancement, large-scale commercialization remains hindered by the high cost of HTMs and the inherent instability of perovskite materials. Among the most widely used HTMs, Spiro-OMeTAD exhibits excellent optoelectronic properties; however, its complex synthesis and costly purification pose major barriers to widespread adoption. Overcoming these challenges requires the development of alternative, cost-effective HTMs with comparable or enhanced performance to improve both the efficiency and stability of PSCs.

This study explores the optoelectronic properties of carbazole-based derivatives as potential HTMs for PSC applications. Thin films were fabricated via the sol–gel spin coating technique on glass substrates, using chlorobenzene as the solvent. The molecular structure of the investigated compounds was confirmed through FTIR analysis, while UV-visible absorption and photoluminescence spectroscopy were employed to assess theiroptical properties. The resulting films exhibited high transparency in the visible spectrum and strong UV absorption, highlighting their suitability for photovoltaic integration. The estimated optical bandgap of the studied compounds was approximately 2.8 eV. Furthermore, a strong green emission in the visible region further underscores their potential for optoelectronic applications.

5.14. Fabrication of Thin-Film Composite Nanofiltration Membrane Employing Polyelectrolyte and Metal–Organic Framework (MOF) via Spin-Spray-Assisted Layer-by-Layer Assembly

• Farid Fadhillah

• Imam Mohammad Ibn Saud Islamic University, Riyadh 11564, Saudi Arabia

Spin-assisted layer-by-layer (LbL) assembly is an innovative method for producing nanostructured thin films, offering enhanced efficiency and precision over traditional dip-coating techniques. This method enables significantly faster deposition and bilayer cycle times while optimizing material usage. In addition, spray LbL systems present advantages in speed and scalability for large-area substrates. By integrating these approaches, spin-spray-assisted LbL assembly allows for rapid assembly and extensive coverage of substrates. In this study, we demonstrated the efficacy of spin-spray LbL assembly in fabricating a thin-film composite nanofiltration (NF) membrane.

In this work, TFC NF consists of multiple layers of polyelectrolyte, and a metal–organic framework (MOF-303) was fabricated to enhance the membrane’s biofouling resistance. Polyethyleneimine (PEI) and poly (sodium-4-styrene sulfonate) (PSS) were sprayed alternately and deposited on the top of a spinning polyethersulfone (PSF) ultrafiltration support to construct thin-film composite NF.

The resulting membrane was examined using standard nanofiltration membrane testing, and its performance is comparable to commercial NF. For instance, five bilayers of PEI/PSS NF membrane, i.e., (PEI/PSS)₅, showed a rejection rate of 42.65 ± 0.17% and a permeability of 9.46 ± 0.14 l/h.bar.m^2, while a commercial NFX membrane from Synder Inc. showed a rejection rate of 53.66 ± 3.23% and a permeability of 3.51 ± 0.42 l/h.bar.m². We fabricated a PEI/PSS membrane coated with MOF303 as the outermost layer. From our preliminary investigation, (PEI/PSS)5-MOF303 with an MOF concentration of 0.05 wt% exhibited a rejection rate of 18.94 ± 1.58% and a permeability of 0.91 ± 0.13 l/h.bar.m². Although this is still a preliminary result, this work shows that spin- and/or spin-spray-assisted layer-by-layer assembly is a promising method for fabricating membranes for various applications. Some further details, such as surface characteristics, are also provided in this work.

5.15. Formation and Microstructural Characterization of Copper Oxide Thin Films

• Haruto Shimada ¹ and Takeo Oku ²

¹ 

Department of Materials Chemistry, The University of Shiga Prefecture, 2500 Hassaka, Hikone, Shiga 522-8533, Japan

² 

The University of Shiga Prefecture, Hikone, Shiga, Japan

Metal-based oxide semiconductors have garnered significant attention as promising materials for solar energy applications. Being composed of metal oxides, oxide semiconductors exhibit superior crystalline stability and lower toxicity compared to organic- and lead-containing perovskite crystals. Additionally, they possess advantageous optical properties, including high light absorption and a band gap width suitable for solar cell applications. Among oxide semiconductors, copper oxides are recognized as one of the most promising materials for p-type semiconductors, with a long history of research. Research and development of solar cells based on copper oxides is accelerating, and some with photovoltaic conversion efficiencies of more than 10% have been fabricated. For solar cells employing oxide semiconductors, sputtering and vacuum deposition methods are primarily utilized. On the other hand, a spin-coating method is widely applied in the fabrication of perovskite solar cells and has attracted attention as a simple and cost-effective thin-film deposition technique, which is necessary for future mass production. Although annealing at high temperatures is commonly used to form thin films of metal oxides, it is also important to reduce the annealing temperature to make this technology widely available. In the present study, copper oxide thin films were fabricated using the spin-coating method, and microstructural analyses were conducted. The successful formation of copper oxide thin films was confirmed, and the microstructures of the thin films were investigated.

5.16. Glass Coatings and Optical Interfaces: Improving Energy Efficiency and Daylight in Architectural Structures

• Kachana Kasulu and Anna Viktorovna Solovieva

• Department of Architecture, Restoration and Design, Engineering Academy, People’s Friendship University of Russia, Moscow, Russia

Introduction: Contemporary architectural approaches prioritise energy-efficient designs that focus on occupant comfort and sustainability. Glass facades and windows are integral to these efforts, providing ample natural light and maintaining visual coherence. However, uncontrolled solar radiation, glare, and poor insulation can undermine a building’s thermal comfort and increase energy use. Recent advancements in thin-film coatings for architectural glass present innovative solutions for optimising daylight, regulating solar heat gain, and enhancing thermal efficiency.

Methods: This study investigated various commercially available and prototype thin-film coatings intended for use on architectural glass. Different deposition techniques were examined, including magnetron sputtering and chemical vapour deposition (CVD). The samples underwent testing under controlled laboratory conditions to assess their optical transmission coefficients, reflection properties, and emissivity. Complementary testing in real-world room conditions further enhanced findings, facilitating a comprehensive evaluation of daylight effectiveness, glare reduction, and their associated impact on internal temperature.

Results: The data obtained indicate that multilayer thin-film coatings can substantially enhance solar radiation control by reducing the transmission of infrared radiation by up to 50% while maintaining an improved transmission coefficient for visible light. Additionally, low-emission coatings effectively diminish heat transfer through glass, resulting in an approximately 20% increase in insulation performance compared to conventional uncoated glazing. Measurements of the interior revealed a notable reduction in glare and a more consistent indoor temperature, enhancing residents’ comfort.

Conclusions: The findings indicate that thin-film coatings on glass serve as an effective solution for architects aiming to balance the benefits of natural light with thermal and visual comfort. These coatings support sustainable development goals and foster a healthier, conducive indoor environment by optimising solar radiation, mitigating glare, and enhancing insulation performance.

5.17. Hybrid Nanostructures of Transition Metal Oxides on Vertical Graphene for Enhanced Electrochemical Performance

• Alina Matei, Cosmin Romanitan, Oana Brincoveanu, Marius Stoian, Octavian-Gabriel Simionescu and Vasilica Tucureanu

• National Institute for Research and Development in Microtechnologies IMT-Bucharest, 077190 Voluntari, Ilfov, Romania

Transition metal oxide (TMO) nanostructures have attracted particular interest due to their multifunctionality, ranging from biomedical devices to electrochemical sensors for wastewater treatment in the textile industry, food processing and packaging, energy storage systems, catalysts, and solar cells. Among the different materials studied, In₂O₃ nanostructures have the advantages of remarkable physicochemical properties, high specific surface area, high surface-to-volume ratio, substantial chemical and environmental stability, and high electron mobility. Over the years, different substrates have been studied for the deposition of TMO thin films to meet the requirements of the targeted fields. In the present work, In₂O₃ nanostructures were obtained by chemical synthesis, and the process conditions and thermal treatment parameters were controlled, with these factors being considered the determining factors with effects on particle size and morphology. To ensure that the oxide nanostructures were compatible with the substrate of interest, graphene hydrophilization was performed. The next step consisted of dispersion of In₂O₃ powders in different media, drop-casting a suspension of oxide particles on the surface of the vertical graphene substrate, and evaporation of the solvent by heat treatment. The analytical methods used indicate a slight tendency of the particles to agglomerate at the surface but also to penetrate between the graphene sheets. FTIR spectroscopy studies and XRD diffraction measurements were carried out to determine their structure. The surface wettability was determined by measuring the contact angle to confirm the hydrophilicity. Furthermore, the electrochemical activities were investigated by cyclic voltammetry.

Acknowledgments: This work was supported by a grant from the Ministry of Research, Innovation and Digitization, CNCS-UEFISCDI, project number PN-IV-P2-2.1-TE-2023-0417, within PNCDI IV and by the Core Program within the National Research Development and Innovation Plan 2022–2027, project no. 2307.

5.18. Influence of Thermal Treatment on Micro-Cu(In,Ga)Se₂ Solar Cells for Micro-Concentrator Photovoltaic Applications

• Marina Alves ^1,2, Ricardo G. Poeira ³, Joaquim Carneiro ², Phillip J. Dale ³ and Sascha Sadewasser ¹

¹ 

International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga s/n, Braga, Portugal

² 

Centre of Physics of Minho and Porto Universities (CF-UM-UP), Azurém Campus, 4800-058 Guimarães, Portugal

³ 

Department of Physics and Materials Science, University of Luxembourg, 41, rue du Brill, L-4422 Belvaux, Luxembourg

The micro-concentrator photovoltaic concept consists in miniaturizing asolar cell to the micrometer scale and using an optical concentrator to collect and focus sunlight onto the micro solar cells. As a result, this approach reduces the use of critical raw materials, while potentially reducing module costs and enhancing power conversion efficiency (PCE). Thin-film Cu(In,Ga)Se₂-based solar cells currently hold a record power conversion efficiency of 23.6% and 23.3% under concentrated illumination.

In this study, micro-holes with diameters of 200 and 250 µm were patterned into a SiO_x insulating matrix on a SLG/SiON/Mo substrate using photolithography [3]. A 1 µm thick Cu-In-Ga precursor was deposited by sputtering; this was followed by selenization at 480 °C in a tube furnace to form CIGS micro-absorbers. One of the precursors underwent a thermal treatment at a nominal temperature of 450 °C prior to selenization. The micro solar cells were completed with a CdS buffer layer deposited by chemical bath deposition and an i-ZnO/ZnO:Al window layer deposited by RF sputtering.

The Cu-In-Ga precursor exhibited a rough surface characterized by island-like grains, with CGI and GGI ratios of 0.75 ± 0.04 and 0.24 ± 0.03, respectively. The thermal treatment resulted in small areas of exposed Mo; however, both thermally treated and untreated micro-absorbers exhibited smooth surfaces after selenization. The treated CIGS micro-absorber exhibited improved elemental composition with a CGI ratio of 0.81 ± 0.06, compared to 0.76 ± 0.13 for untreated micro-absorber.

The annealed CIGS micro-cells display better overall performance, with higher average open-circuit voltage (V_oc). The best annealed CIGS micro-cell achieved a maximum PCE of 1.44%, with a V_oc and J_sc of 249 mV and 16.5 mA/cm². In contrast, the untreated CIGS micro-cells achieved a PCE of 0.47%, with a V_oc of 198 mV and a J_sc of 9.2 mA/cm², respectively.

5.19. Innovative Solvent-Based Pressure-Sensitive Paints for Aerodynamic Testing in Wind Engineering

• Oliwia Ufniarz

• Tadeusz Kościuszko Cracow University of Technology, Faculty of Mechanical Engineering, 31-155 Kraków, Poland

This work introduces an innovative Pressure-Sensitive Paint (PSP) system based on solvent quenching mechanisms (SQ-PSP), tailored for precise aerodynamic testing in wind engineering applications. The SQ-PSP system enhances the capabilities of traditional PSP technology by employing a solvent to quench fluorescence, enabling accurate pressure distribution mapping on structural models tested in wind tunnels.

The system’s polymer matrix incorporates luminescent pressure sensors that react dynamically to pressure changes, offering high sensitivity and stability. Validation tests demonstrated linearity in a pressure range from −500 hPa to +500 hPa, ensuring reliable performance across diverse aerodynamic scenarios. A key advantage of the SQ-PSP system is its ease of application and rapid data acquisition, making it a superior alternative to traditional pressure taps in terms of both efficiency and measurement precision.

Wind tunnel studies using architectural models confirmed the system’s effectiveness, showing strong agreement with classical measurement methods in positive pressure ranges. However, challenges in capturing negative pressure variations highlight areas for further refinement. Despite these limitations, the SQ-PSP system presents significant potential as a cutting-edge tool for analyzing complex pressure distributions, contributing to the optimization of structural designs and improving urban wind comfort through enhanced aerodynamic modeling.

Acknowledgments: This research was supported by the Foundation for Polish Science under the Proof of Concept project (FENG.02.07-IP.05-0451/23), titled “Novel Polymer-Based Pressure Sensitive Paint Systems for Aerodynamic Testing to Enhance Predictions of Structural Impact on Atmospheric Phenomena and Urban Comfort.”

5.20. Localized Effects in Graphene Oxide Systems: A Pathway to Hyperbolic Metamaterials

• Grazia Giuseppina Politano

• Department of Environmental Engineering, University of Calabria, 87036 Rende, CS, Italy

Graphene oxide (GO) has emerged as a carbon-based nanomaterial providing an alternative pathway to graphene. One of its most notable features is the ability to partially reduce it, resulting in graphene-like sheets through the removal of oxygen-containing functional groups. Herein, the effect of localized interactions in a Ag/GO/Au multilayer system was studied to explore its potential for photonic applications. The Ag/GO/Au structure was fabricated through a sequential deposition process. First, silver thin films (10 nm) were deposited onto glass substrates using a DC magnetron sputtering system. Subsequently, graphene oxide (GO) layers (8 nm) were applied onto the silver films via a dip-coating technique. Finally, gold thin films (15 nm) were deposited over the GO/Ag/glass substrates using the same sputtering system. Micro-Raman Spectroscopy, SEM (Scanning electron microscopy) and Variable Angle Ellipsometry measurements were performed on the Ag/GO/Au structure.

Micro-Raman measurements confirmed that the atomic frame of sp² carbon formed in RGO (reduced graphene oxide), thus indicating the transition from sp³ (oxidized regions) to sp² (graphitic regions) hybridization.

An interesting behavior of the GO dip-coated on magnetron sputtered silver with the formation of Ag nanostructures on top of the GO layer was reported using SEM. Furthermore, the dispersion laws estimated for the glass/Ag/GO/Au structure by ellipsometry characterization seemed to confirm the morphological behavior observed with SEM measurements. The gold thin film adjusted elastically on the GO/Ag/glass sample, without modifying its overall optical behavior, whereas the interface GO/Ag was more complex. Additionally, calculations based on effective medium theory (EMT) highlighted the potential of Ag/GO structures in multilayer hyperbolic metamaterials for photonic applications.

5.21. Modulable Longwave Pass Filters Based on Kapton Films

• Gianfranco Carotenuto

• Institute for Polymers, Composites and Biomaterials (IPCB-CNR), Italian National Research Council, 80078 Pozzuoli, Naples, Italy

Kapton can be classified as an optical-grade plastic material because its amorphous nature does not allow light-scattering phenomena. Kapton films are amber-colored and have a unique optical absorption spectrum, characterized by a high transmittance value above 500 nm (from yellow-red to near-infrared spectral regions) and an extremely high absorbance value below 500 nm (from blue-violet to ultra-violet spectral regions). Owing to these special optical characteristics, Kapton films can be used as optical limiters (i.e., absorption-type optical filters), specifically as longwave pass (LWP) filters, and such optical devices can be used as ‘optical windows’ for many technological applications like the protection of sensors, optoelectronic devices (e.g., IR sensors and detectors), etc., from high-energy radiation (e.g., UV light, X-ray, etc.). This thermoplastic polymer has a very high thermal stability; indeed, its maximum service temperature is ca. 400 °C. However, Kapton can be carbonized/graphitized by heating at very high temperatures (above 1000 °C) to produce well-oriented graphite films. This process can be controlled and used to change Kapton’s absorption profile. In particular, it is possible to modulate Kapton’s optical absorption behavior by heating the polymer at temperatures slightly above 400 °C. In particular, heating Kapton above 400 °C leaves the film’s optical transparency practically unmodified but causes a red-shift of the cut-on edge wavelength because of the formation of conjugated structures, with delocalized π-bonded electrons, in the Kapton chemical structure (very mild carbonization process). Therefore, it is possible to tune the cut-on edge wavelength of this LWP filter simply by applying a controlled thermal annealing treatment to the pristine film. Here, the optical properties of Kapton films modified by thermal treatment at temperatures higher than 400 °C have been investigated by absorption optical spectroscopy (UV-Vis spectroscopy).

5.22. Multifunctional Dark-Colored Coating for Roof Renovation: Combining Corrosion Protection and Heat Reduction in a Single Application

• Katarzyna Suchoń, Ewa Langer and Małgorzata Zubielewicz

• Łukasiewicz Research Network—Institute for Engineering of Polymer Materials and Dyes, ul. Marii Skłodowskiej Curie 55 87-100 Toruń, Poland; Centre for Paints and Plastics in Gliwice, ul. Chorzowska 50A, 44-100 Gliwice

In response to the growing challenges of global warming, one of the key phenomena affecting thermal comfort and energy efficiency in cities is the Urban Heat Island (UHI) effect. This refers to higher temperatures in urban areas compared to rural surroundings, caused by building materials like concrete and asphalt that absorb and store heat. In cities with dense buildings and limited green space, there is increased demand for air conditioning, leading to higher energy costs and greater air pollution. Mitigating the UHI effect is thus essential for sustainable urban development.

Roof surfaces, highly exposed to solar radiation, are among the main contributors to heat accumulation. Applying appropriate thermal insulation coatings can significantly improve building energy efficiency. Developing coatings with high Total Solar Reflectance (TSR) can reduce roof temperatures and decrease air conditioning demand, addressing rising energy costs and climate change.

This study aimed to develop dark-colored, multifunctional roof coatings combining corrosion resistance and heat-reduction properties. Direct-to-metal (DTM) coatings, which eliminate the need for an anti-corrosion primer, simplify application and reduce painting time. These formulations incorporated near-infrared (NIR) reflective inorganic pigments that reflect solar radiation in the NIR spectrum, improving thermal performance.

The coatings underwent extensive testing, including adhesion, impact resistance, flexibility, and accelerated aging in salt spray, humidity, and UV chambers. Optical and thermal properties were assessed with UV/VIS/NIR spectrophotometry, and emittance was measured with Total Hemispherical Emittance Measurements.

The coatings demonstrated excellent adhesion and corrosion resistance, with heat-reflective NIR pigments reducing substrate temperature even in dark-gray colors. These results highlight the coatings’ effectiveness in mitigating the UHI effect and improving building energy efficiency.

Acknowledgments: This work was financially supported by the Łukasiewicz Research Network Centre (Poland)—grant number: 1/Ł-IMPiB/CŁ/2021.

5.23. Nanoceramic-Enhanced Cement and Coatings: Pioneering Advanced Materials for Enhancing Performance and Durability

• Mahdiyeh Rahmani Del Bakhshayesh ¹ and Azizeh Rahmani Del Bakhshayesh ²

¹ 

Al-Zahra Technical & Vocational College, Tabriz, Iran

² 

Department of Tissue Engineering, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran

Introduction: Nanoceramic materials are playing a pivotal role in advancing the development of high-performance coatings and thin films, significantly improving the performance and durability of cementitious composites and surface treatments. These materials, including nano-silica, nano-titania, and nano-alumina, have shown exceptional promise in enhancing key properties such as mechanical strength, chemical resistance, and environmental resilience. The incorporation of these nanoceramics into coatings has led to substantial improvements, making them an ideal solution for various industrial applications.

Methods: The addition of nano-silica to cementitious materials has been shown to increase compressive strength by up to 20%, primarily due to its pozzolanic activity, which facilitates the formation of additional cementitious compounds and refines the microstructure at the nanoscale. This refinement process results in a more compact and homogeneous material, enhancing its mechanical properties. Similarly, nano-titania and nano-alumina contribute significantly to reduced permeability and enhanced chemical resistance, improving the durability of coatings under harsh environmental conditions. These nanoparticles fill voids within the material matrix, refining the interfaces between particles and enhancing overall structural integrity.

Results: In recent studies, microstructural investigations have provided visual confirmation of these enhancements, showing denser, more uniform networks within the material. These improved structures not only contribute to the mechanical properties but also the longevity and environmental performance of the coatings, ensuring that they can withstand the effects of weathering, chemical exposure, and physical wear.

Conclusion: The integration of nanoceramic materials into coatings represents a significant breakthrough in surface engineering, offering new opportunities for creating sustainable and high-performance materials in the construction industry. Future research will focus on optimizing nanoparticle concentrations, assessing long-term durability and performance under real-world conditions, and evaluating the environmental and economic impacts of these advanced materials. With continued innovation, nanoceramics have the potential to revolutionize the field of coatings and surface treatments.

5.24. Optical Coatings and Thin Film Deposition: Selecting Deposition Materials for PVD and IAD

• Ahmed Mohmed

• BACHELOR OF SCIENCE—DEPARTMENT PHYSICS (BAS) Ain Shams University, Cairo, Egypt

Introduction: Thin film deposition is an essential process in various industries, including optics, electronics, and aerospace. Among the most effective techniques, Physical Vapor Deposition (PVD) and Ion-Assisted Deposition (IAD) provide high-quality coatings with improved adhesion, mechanical strength, and optical performance. The choice of deposition materials is critical, as it directly influences the film’s durability, functionality, and efficiency.

Methods: PVD involves transferring material from a source to a substrate in a vacuum environment. Common methods include evaporation and sputtering, where the material is either thermally vaporized or ejected by high-energy ion bombardment. IAD enhances PVD by introducing ion beams during deposition, improving film density, adhesion, and stress control. The selection of deposition materials depends on properties such as melting point, optical transparency, hardness, and chemical stability.

Results: Studies show that materials like titanium (Ti), silicon dioxide (SiO₂), and aluminum oxide (Al₂O₃) perform exceptionally well in PVD coatings, particularly for optical and wear-resistant applications. When combined with IAD, these films exhibit higher density, reduced defects, and better environmental resistance. However, materials with low thermal stability or high volatility require optimized deposition conditions to achieve uniform coatings.

Conclusions: The effectiveness of thin film deposition relies on selecting suitable materials and optimizing process parameters. PVD ensures high-quality coatings, while IAD further refines film characteristics, enhancing durability and performance. As deposition technologies evolve, new material innovations will continue to expand thin film applications across multiple industries, driving advancements in optics, electronics, and protective coatings. Understanding the interplay between deposition techniques and material properties is essential for producing high-performance thin films.

5.25. Oxidation and Wear Protection of Pultruded C/C Composites Using Atmospheric Plasma-Sprayed Environmental Barrier Coatings

• Maximilian Grimm ¹, Husam Ahmad ², Marcus Knobloch ³, Maik Trautmann ², David Löpitz ³, Thomas Lindner ¹, Guntram Wagner ² and Thomas Lampke ¹

¹ 

Materials and Surface Engineering, Institute of Materials Science and Engineering, Chemnitz University of Technology, 09107 Chemnitz, Germany

² 

Group of Composites and Material Compounds, Institute of Materials Science and Engineering, Chemnitz University of Technology, 09125 Chemnitz, Germany

³ 

Fraunhofer Institute for Machine Tools and Forming Technology IWU, Reichenhainer Straße 88, 09126 Chemnitz, Germany

C/C composites exhibit a unique property profile, including high specific strength, flexural strength, excellent thermal shock resistance and low density. These properties make C/C an attractive material with great potential for high-temperature applications such as furnace technology. However, the low oxidation resistance of the material at high temperatures as well as its low wear resistance are critical factors that restrict its in-service lifetime and can lead to premature material failure.

This study investigates to what extent oxidation and wear resistance can be increased by the deposition of atmospheric plasma-sprayed coatings. Therefore, different coating systems are investigated, which consist of Mo or Si as intermediate coating and Al₂O₃, Al₂O₃-8%Cr₂O₃, Al₂O₃-40%TiO₂, an experimental (Al,Cr,Ti)₂O₃ solid solution or Yb₂Si₂O₇ as top coat. The wear resistance is determined by means of a ball-on-disc test, while the oxidation protection and damage mechanisms of the coating systems are evaluated by thermocyclic tests up to 1000 °C and rapid cooling in air. The microstructure of the coatings is analyzed using a scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD).

The results show that atmospheric plasma-sprayed coatings, despite their typical microstructure, which is characterized by pores and microcracks, can significantly improve the oxidation resistance of the C/C composite by reducing the rate of degradation in an oxidative environment. In addition, the oxide ceramic coatings provide considerably higher wear resistance than the C/C composite.

5.26. Pyrolysis Conditions Optimization for Biochar Synthesis as Catalyst for Water Splitting Applications by Applying Response Surface Methodology

• Raquel Domínguez Alonso, Aida M.Díez, Marta Pazos and M.Ángeles Sanromán

• BIOSUV research group, Chemical Engineering department, University of Vigo

Introduction: The global annual accumulation of food waste has been increasing in the last years. Thus, biomass-based catalysts have been selected as a solution to reduce this waste and obtain energy by water splitting process. Therefore, pyrolysis conditions have been optimised by Response surface methodology (RSM) to improve the obtain biochar properties and quality, diminishing overpotential and Tafel slope responses to deal with thermodynamic issues from water splitting. Moreover, our catalyst benefits for its simple coating, as the synthesized biochar is deposited into the selected support by drop deposition where the own material acts as adhesive agent, avoiding polymers as Nafion^® or Sustainion^®.

Methods: 1 g of orange peel was pyrolysed in a tubular oven under different conditions, considering the reaction time (30–720 min) and the reaction temperature (300–900 °C), with a heating rate of 10 °C/min. Thus, software DesignExpert^® has been used for RSM, establishing both reaction temperature and time as input factors and overpotential and Tafel slope as response factors.

Results: Our results showed that the optimal pyrolysis conditions obtained by RSM were applying the highest temperature (900 °C) with the lowest treatment time (30 min), attaining the minimise overpotential (374.8 mV at 10 mA/cm²) for water splitting.

Conclusions: This work demonstrates competitive results in terms of overpotential and Tafel slope with the benchmark catalysts for water splitting, opening the importance of synthesis conditions optimization for catalytic properties.

Acknowledgments: This work was supported by Project H₂-ZeroWaste from AXA Research Fund and the project CINTECX-CHALLENGE 2024. Moreover, the researcher Aida M. Díez is grateful to Ramón y Cajal (RYC2023-044934-I) financial support (MICIU).

5.27. Semitransparent Gold-Embedded Anodic Titania Nanotubes: Harnessing Plasmonic and Photoelectrochemical Synergies for Visible-Light Applications

• Saiful Islam Khan ¹, Katarzyna Siuzdak ² and Katarzyna Grochowska ³

¹ 

Department of Physical Aspects of Ecoenergy, Centre of Plasma and Laser Engineering, Institute of Fluid-Flow Machinery, Polish Academy of Sciences, Fiszera 14 st., 80-231 Gdańsk, Poland

² 

Head of the Department of Physical Aspects of Ecoenergy, Centre of Plasma and Laser Engineering, Institute of Fluid-Flow Machinery, Polish Academy of Sciences, Fiszera 14 st., 80-231 Gdańsk, Poland

³ 

Department of Physical Aspects of Ecoenergy, Centre of Plasma and Laser Engineering, Institute of Fluid-Flow Machinery, Polish Academy of Sciences, Fiszera 14 st., 80-231 Gdańsk, Poland

Anodic titania nanotubes are characterized by their high degree of vertical alignment, resulting in structures with exceptional surface area, physical, and electrochemical properties. However, their intrinsic wide band gap (ca. 3.2 eV for anatase form) limits their absorption to the UV spectrum, necessitating strategies such as doping and plasmonic decoration to extend their activity into the visible range. Additionally, the semitransparency of these structures can be leveraged to enhance light management and integration into optoelectronic and solar-energy-harvesting devices.

Gold nanoparticles decorated anodic titania nanotubes, exhibiting localized surface plasmon resonance, can potentially improve photocatalytic activity, visible-light absorption, nonlinear optical behavior, and the efficiency of solar energy and photonic devices. These materials can be synthesized through various approaches, including laser-treated titania nanotubes coated with a gold thin film or the laser treatment of oxide nanotubes formed from TiAu homogeneously co-sputtered alloys. However, laser processing often results in non-uniform gold nanoparticle distribution, predominantly on the nanotube surface area, leading to issues like melting, agglomeration, or polydispersity. To address these challenges, we have developed semitransparent anodic nanotubes embedded with gold nanoparticles. These structures were fabricated by anodizing a multilayered film stack composed of alternating Ti-sputtered layers and TiAu co-sputtered layers. SEM analysis revealed well-formed, uniformly distributed nanotubes and the Raman spectra confirmed the presence of the anatase phase in the prepared materials, with up to 7% of Au content. The UV–vis spectra also revealed a redshift of the absorption band beyond 400 nm, and energy band-gap reduction was observed compared to the bare titania material. Furthermore, the samples exhibited superior anodic current densities, particularly favoring oxygen evolution reactions, reaching up to 2.7 mAcm⁻² for the sample with 5% Au content. These results underscore the potential of such gold nanoparticle-embedded nanotubular architectures for advanced photoelectrochemical applications.

5.28. Structure and Properties of W_1−xAl_xB_2−z Coatings

• Ewa Agnieszka Wojtiuk and Tomasz Mościcki

• Institue of Fundamental Technological Research Polish Academy of Sciences, Pawińskiego 5B, 02-106 Warsaw, Poland

In the pursuit of advanced materials with exceptional properties, tungsten borides have attracted significant attention due to their remarkable hardness, thermal stability, and wear resistance. The crystallographic structure of such materials plays a pivotal role in determining their physical, mechanical, and thermal characteristics. Among these, aluminum-doped tungsten borides (W_1−xAl_xB_2−z) stand out, offering excellent mechanical and thermal properties. These materials show great promise for applications as protective coatings capable of maintaining stability at high temperatures.

To achieve the desired material structure, an innovative magnetron deposition method was employed, combining direct-current magnetron sputtering (DC) and High-Power Impulse Magnetron Sputtering (HiPIMS) techniques. The layer was deposited using two targets: AlB₂ (DC) and WB_2.5 (HiPIMS). An original method involving mass measurements and microscopic observations was applied to determine the density, which was subsequently used to calculate the thermal conductivity. The measured thermal conductivity values (5–8 W/(mK)) classify these materials as thermoelectric. Mechanical testing revealed very high hardness (~30 GPa for doping below 10% atomic aluminum) and a favorable plasticity index (H/E*). As aluminum content increased in W_1−xAl_xB_2−z layers, a slight reduction in density and hardness was observed, along with an increase in thermal conductivity.

Experimental results were compared with theoretical values obtained via DFT calculations. All W_1−xAl_xB_2−z structures analyzed through DFT were found to be mechanically and thermally stable. The experimentally determined hardness values exceeded those predicted by DFT, underscoring the significant influence of aluminum doping.

This study highlights how deposition processes affect crystallinity, texture, and microstructural features, which in turn influence the material’s mechanical and thermal properties. Optimization of deposition conditions and doping strategies enabled the development of W_1−xAl_xB_2−z—a promising material with potential industrial applications.

Funding: This work was funded by the National Science Centre (NCN, Poland), Project number: 2022/47/B/ST8/01296.

5.29. Superhydrophobic Copper Foams for Use as Marine Water Purification Filters

• Aikaterini Baxevani and Fani Stergioudi

• Physical Metallurgy Laboratory, School of Mechanical Engineering, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece

This research addresses marine pollution, a critical environmental issue, by developing an innovative solution to overcome the limitations of traditional cleaning methods. Existing techniques are often inefficient due to their complexity, time-intensive processes, specialized personnel requirements, and high costs. This study explores a novel approach: the development of a superhydrophobic coating on copper foams as an efficient alternative for marine depollution.

Various efforts in creating hydrophobic porous materials, such as electrospinning and chemical vapor deposition, have faced challenges like high equipment costs, energy demands, and the use of harmful chemicals. In contrast, this study proposes a cost-effective and simplified method. A superhydrophobic coating was successfully fabricated on copper foams with varying levels of surface roughness through a two-step immersion process in silver nitrate and stearic acid solutions. Importantly, the substrate’s surface roughness significantly influenced the growth of silver dendrites and the morphologies of stearic acid, resulting in distinct structural differences between rough and smooth copper foams. This process requires minimal chemicals, simple equipment, and fewer steps, making it a practical and sustainable option.

The hydrophobic coatings achieved exceptional contact angles of 180°, significantly higher than those reported in most studies. The coatings demonstrated remarkable thermal and chemical stability when subjected to different temperatures (100 °C and −15 °C) and immersion in water and NaCl, HCl, and NaOH solutions, even after a 40 h exposure. The separation efficiency remained consistently above 94% across various pollutants, demonstrating excellent stability and durability regardless of the substrate’s surface roughness. The mechanical durability of the modified copper foams was evaluated through dragging tests and exposure to ultrasound, exhibiting promising results.

This study offers a transformative approach to marine depollution, presenting cost-effective and robust solutions that align with existing environmental strategies to protect and restore marine ecosystems.

5.30. Surface Roughness and Fractal Analysis of TiO₂ Thin Films by DC Sputtering

• Helena Vasconcelos, Telmo Eleutério and Maria Meirelles

• Faculty of Sciences and Technology, University of the Azores (FCT-UAc), 9500-321 Ponta Delgada, Portugal

This study investigates the surface roughness and fractal characteristics of TiO₂ thin films deposited via DC reactive magnetron sputtering, using an Ar/O₂ gas mixture and varying sputtering powers. The films’ surface morphology was characterized using Scanning Electron Microscopy (SEM) and topographic mapping. Roughness parameters such as Ra (average roughness), Rq (root mean square roughness), Rt (total height of the roughness profile), and Rz (peak-to-valley roughness) were quantified to assess the surface quality. Additionally, fractal analysis was conducted to evaluate the complexity of surface features across multiple length scales, using both “length-scale” and “area-scale” frameworks to explore hierarchical structures.

The key analyses were performed using MountainsMap^® software, which enabled 3D surface reconstruction, fractal dimension evaluation, and advanced surface metrology. The TiO₂ thin films were deposited under various O₂ ratios and sputtering powers to explore the influence of these parameters on surface roughness and fractal characteristics.

This investigation combines both roughness and fractal metrics, offering a comprehensive framework for analyzing the interplay between deposition conditions and surface properties. The results provide valuable insights for tailoring TiO₂ thin films for use in applications such as photocatalytic devices, sensors, and other technologies that require precise control of surface topography, enhancing their functionality and performance.

5.31. Tailoring Wettability Through Coating Deposition on High-Voltage Overhead Conductors to Decrease Corona Discharge Power Losses

• Kirill Emelyanenko, Ludmila Boinovich and Alexandre Emelyanenko

• A. N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Leninsky Prospect 31, 119071 Moscow, Russia

Meeting the demands of modern high-voltage transmission line applications requires novel functional coatings that minimize corona discharge losses while providing sufficiently low ice adhesion and adequate corrosion protection. This work presents comprehensive results from an extensive study of superhydrophobic (SHC), superhydrophilic (SPhil), hydrophilic (Phil), and slippery liquid-infused porous surfaces (SLIPSs) under alternating current corona discharge. Our experiments confirm that coatings at both extremes of the wettability spectrum—water-repelling SHC and water-attracting SPhil—can reduce corona discharge currents by two to four times under adverse weather conditions, whereas SLIPS coatings, despite their water repellency, may actually increase corona currents in rainy conditions.

Furthermore, we observed distinct differences in long-term coating stability under harsh corona discharge conditions, including ozone exposure, UV radiation, and ion bombardment. SLIPS coatings rapidly degrade due to depletion of the lubricating layer, while SHC coatings exhibit very slow, yet discernible deterioration. In contrast, Phil and SPhil coatings tend to improve their corona-protective properties upon exposure to corona discharge. Among these options, hydrophilic organosilane coatings offer the best overall balance: they significantly reduce corona power losses, maintain ice adhesion levels comparable to bare wires, and achieve a threefold reduction in corrosion currents. Meanwhile, superhydrophilic coatings demonstrate reduced corona discharge but suffer from increased ice adhesion and corrosion rates.

These findings underscore the importance of selecting and optimizing coatings to suit specific climatic conditions. In regions with significant icing, durable superhydrophobic coatings hold promise, provided further work is done to enhance their longevity. In warmer, humid climates, hydrophilic and superhydrophilic coatings are more suitable. Overall, our results highlight how tailoring surface wettability can mitigate corona discharge and other environmental impacts, paving the way for improved performance and reliability of high-voltage transmission lines.

5.32. Tailoring the Optical and Sensing Properties of Sol–Gel Niobia Coatings via Doping with Silica and Gold Nanoparticles

• Tsvetanka Babeva ^1,2, Venelin Pavlov ^1,3, Georgi Zlatinov ^1,3, Gergana Alexieva ^1,3, Rosen Georgiev ¹, Biliana Georgieva ¹, Penka Terziyska ¹ and Katerina Lazarova ¹

¹ 

Institute of Optical Materials and Technologies “Acad. J. Malinowski”, Bulgarian Academy of Sciences, Akad. G. Bonchev Str., Bl. 109, 1113 Sofia, Bulgaria

² 

National Centre of Excellence for Mechatronics and Clean Technologies, Bulgaria

³ 

Faculty of Physics, University of Sofia, 5 James Bourchier Blvd., 1164 Sofia, Bulgaria

Niobium pentoxide (Nb₂O₅ or niobia) exhibits several key properties that make it an excellent optical material. These include exceptional stability, resistance to acidic and basic environments, high optical transmission and refractive index, and minimal light scattering, which further enhance its performance in optical applications. Among the various methods for depositing Nb₂O₅ thin films, sol–gel stands out as a particularly promising approach due to its versatility, scalability, and the ability to precisely tailor material properties for a broad range of applications.

In the current study single- and multi-layered niobia coatings were prepared by spin-coating a niobium sol, which was synthesized using niobium chloride as the precursor and ethanol and water as solvents, followed by annealing at 320 °C to form the niobia film. Doped niobia films were prepared by incorporating commercially available SiO₂ (Ludox) and Au nanoparticles (NPs) into the sol before spin-coating of the films. After annealing the silica-doped films, they were subjected to chemical etching for varying durations to remove the silica phase. This process generated porosity within the films, which in turn enabled the tailoring of both their optical and sensing properties.

The morphology of the films was investigated using transmission electron microscopy (TEM). The optical parameters and film thicknesses were determined by nonlinear curve fitting of the reflection spectra, and the results were cross-validated through additional ellipsometric measurements. Effective medium approximation was used to assess the degree of porosity. The sensing properties of the films were evaluated by using both quartz crystal microbalance (QCM) and optical reflectance spectra measurements, recorded prior to and during exposure to the analyte (acetone vapors).

The study demonstrated that silica NPs enhanced the porosity of the niobia coatings, resulting in vapor-sensitive films with tunable optical and sensing properties. The gold NP doping further improved the sensing performance of the studied films.

5.33. Zinc Oxide Nanoparticles in Cement-Based Antibacterial Coatings: A Pathway to Hygienic and Durable Construction Materials

• Mahdiyeh Rahmani Del Bakhshayesh ¹ and Azizeh Rahmani Del Bakhshayesh ²

¹ 

Al-Zahra Technical & Vocational College, Tabriz, Iran

² 

Department of Tissue Engineering, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran

Introduction: Antibacterial coatings are becoming essential in construction materials to prevent microbial growth and improve hygiene, particularly in environments prone to bacterial contamination. Zinc oxide (ZnO) nanoparticles have emerged as a highly effective antimicrobial additive, offering unique properties such as high surface area, photocatalytic activity, and the ability to generate reactive oxygen species. When incorporated into cementitious coatings, ZnO nanoparticles provide dual benefits by enhancing both mechanical properties and antimicrobial functionality.

Methods: Recent advancements highlight the potential of ZnO-enhanced cement coatings to inhibit common pathogens, including Escherichia coli and Staphylococcus aureus. The antibacterial activity stems from the nanoparticles’ ability to disrupt bacterial membranes and produce reactive oxygen species, effectively controlling microbial growth.

Results: The addition of ZnO improves the durability and compressive strength of cement, ensuring the material’s structural integrity. The uniform dispersion of zinc oxide nanoparticles in the cement matrix contributes to consistent antibacterial performance and increased durability.

Conclusion: Recent studies have shown that ZnO-based antibacterial coatings represent a sustainable and innovative approach to addressing hygiene challenges in construction while maintaining high material performance. Future research is needed to optimize nanoparticle concentrations, ensure long-term antimicrobial efficacy, and evaluate the environmental and economic impacts of these coatings. This integration of functionality and durability underscores the transformative potential of ZnO nanoparticle-based coatings in modern construction and infrastructure.

6. Corrosion, Erosion and the Tribological and Mechanical Aspects of Coatings

6.1. Advanced Protective Epoxy Coatings with Photoactive TiO₂-LDO Nanofillers for Corrosion Protection and Potential NOx Mitigation

• Muhammad Ahsan Iqbal ¹, Humaira Asghar ², Valter Maurino ², Endzhe Matykina ¹, Raúl Arrabal ¹ and Marta Mohedano ¹

¹ 

Departamento de Ingeniería Química y de Materiales, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain

² 

Department of Chemistry, University of Torino, Via Giuria 7, 10125 Torino, Italy

Epoxy resins serve as anticorrosive coatings due to their robust mechanical properties, chemical resistance, and adhesion. Enhancing these coatings with nanoparticles—particularly titanium dioxide (TiO₂)—has proven effective in improving both corrosion resistance and other functional properties. In this work, we synthesized a photoactive TiO₂-based ZnAl-layered double oxide (TiO₂-LDO; 1:10) nanocatalyst via a wet impregnation method and incorporated it into an epoxy matrix. The epoxy resin, formulated with 2 wt.% TiO₂-LDO, was applied to AA2024 substrates using a coating bar coater, yielding a cured film thickness of 20 ± 2 µm. The developed TiO₂-LDO nanocatalyst exhibited high selectivity in the NOx abatement and a minimum NO₂ release (3–4%), achieving remarkably up to an 80% NO photoconversion efficiency under 20 W/m² of irradiation in a customized continuous-flow portable photoreactor, designed specifically for NOx studies. In comparison, while TiO₂ (anatase) achieved a similar NO conversion efficiency, it generated 20–25% NO₂ as a byproduct, which is even more toxic than NOx, whereas LDO alone produced minimal NO₂ but achieved a lower NO conversion efficiency of 25–30%.

Electrochemical impedance spectroscopy (EIS) over 28 days revealed that incorporating TiO₂-LDO into the epoxy coating provided a comparable corrosion resistance to the pure resin. However, the improvement was pronounced when the systems were exposed to UV irradiation (10 days of aging with fluorescent source with λ_max = 365 nm, 20 W·m⁻²), which induces micropore formation in the pure epoxy film compared to epoxy with TiO₂-LDO, and thus improved corrosion resistance for the epoxy composite on AA2024. The results underscore the dual functionality of TiO₂-LDO as both a photoactive nanocatalyst (air pollution) and an effective anticorrosion additive, offering a promising, environmentally friendly solution for UV-resistant corrosion protection.

6.2. Corrosion Fatigue Life Analysis of Chip-Based Hot-Extruded Aluminum Alloy AA6060

• Alexandros Prospathopoulos, Apostolos Argyros, Eleni Lamprou and Nikolaos Michailidis

• Mechanical Engineering Department, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece

Secondary aluminum production through the recycling of aluminum chips originating from machining proceedings (e.g., milling, drilling) has occupied the top position among the exploitation procedures of wastes in the last decade. In particular, the solid-state method that replaces the conventional melting and casting stages with a cold pre-compaction stage before the final hot extrusion is a promising new field of interest, taking into account the energy consumption, material loss, processing steps, environmental contamination, cost, etc. The literature results reveal that material produced by the innovative processing route (including cold compaction followed by hot extrusion) is optimum, with very competitive mechanical properties. The present study explores the influence of different heat treatments (no heat treatment, natural aging, artificial aging) on the chip-based hot-extruded aluminum alloy AA6060’s fatigue and fatigue corrosion behavior. Experiments were performed on cast-based hot-extruded specimens for comparison reasons. In addition, a detailed microstructural analysis of the micro-morphological fatigue failure features was carried out.

Although the results pointed out the supremacy of cast-based material in the majority of cases of fatigue and fatigue corrosion, the significance of microstructural coherency was highlighted among chip boundaries. Improving the chip bonding quality could lead to a remarkable enhancement in the fatigue life of the recycled chips subjected to hot extrusion and heat-treated processes.

6.3. Development of Biochar-Based Sustainable Corrosion-Resistant Coating

• Ganesh Zade and Malhari Kulkarni

• Department of Chemical Engineering, Dr. Vishwanath Karad MIT World Peace University, Kothrud, Pune, India-411038

Coating technology involves the application of a thin layer of material onto a substrate to enhance its surface properties, including protection, functionality, and aesthetics. Coatings can be made from various materials such as polymers, pigments, additives, and solvents, depending on the intended application. These coating layers serve multiple purposes, such as providing corrosion resistance, improving wear durability, reducing friction, or offering thermal and electrical insulation. The development of sustainable coating technologies is essential to addressing environmental, economic, and social challenges associated with conventional coatings. Traditional coatings often rely on petroleum-based resources and volatile organic compounds (VOCs), contributing to greenhouse gas emissions, air pollution, and health hazards. As global industries strive to reduce their environmental carbon footprint, the demand for eco-friendly coating alternatives has grown significantly.

Therefore, a biochar-based sustainable coating has been developed to achieve a sustainable alternative for conventional coatings. Biochar from different sources of biomasses were prepared by pyrolysis at varying conditions and characterized by FTIR, FESEM, BET, XRD, etc. Derived biochar offers unique properties such as high thermal stability and chemical inertness, making it an effective component for corrosion protection. When this biochar is incorporated into coating formulations, it forms a barrier that inhibits the diffusion of corrosive agents like water, oxygen, and chlorides to metal surfaces. Additionally, the carbon-rich structure of biochar enhances the durability of coatings and provides cathodic protection, reducing metal oxidation rates. These coatings have potential applications in industries such as the infrastructure, marine, and automotive sectors, where corrosion resistance is critical. Beyond these benefits, biochar-based coatings promote environmental sustainability by utilizing renewable biomass resources and reducing reliance on petroleum-based materials. However, further research is needed to optimize coating techniques and evaluate the long-term stability and environmental impacts of biochar-coated products.

6.4. Development of Sustainable Anticorrosive Coatings Based on Pinus Radiata Bark Wax

• Daniel Sandoval-Rivas ¹, Jesús Ramírez ¹, Matías Ignacio Hepp ² and Manuel Meléndrez ³

¹ 

Facultad de Ingeniería, Universidad San Sebastián, Lientur 1457, Concepción, Chile

² 

Laboratorio de Investigación en Ciencias Biomédicas, Departamento de Ciencias Básicas y Morfología, Facultad de Medicina, Universidad Católica de la Santísima Concepción, Concepción, Chile

³ 

Facultad de Ciencias de la Rehabilitación, Universidad San Sebastián, Lientur 1457, Concepción, Chile

Corrosion is a natural phenomenon that significantly affects metal structures, leading to deterioration, reduced service life, and structural failures, with severe economic and environmental consequences. The Organization for Economic Co-operation and Development (OECD) estimates that corrosion accounts for up to 3% of the GDP in developed countries. In Chile, a country with an extensive coastline and a strong industrial sector, critical infrastructures such as bridges, power plants, and offshore platforms are continuously exposed to corrosive environments. Climate change exacerbates these conditions by increasing coastal salinity and acid rain, accelerating metal degradation, raising maintenance costs, and impacting sustainability.

Traditional anticorrosive coatings contain materials with significant health and environmental risks, including epoxy resins with bisphenol A (BPA), carcinogenic lead chromate pigments, volatile organic compounds (VOCs), and bioaccumulative biocides. Developing safer and sustainable alternatives is crucial to reducing these risks while maintaining corrosion protection effectiveness. This study explores the use of Pinus radiata bark wax extracts as a novel raw material for sustainable anticorrosive coatings. Utilizing this abundant forestry byproduct promotes circular economy principles by repurposing waste while reducing synthetic material dependency and carbon footprint.

Electrochemical impedance spectroscopy (EIS) tests were conducted following ASTM G106 standards to evaluate corrosion resistance. The developed coating exhibited impedance modulus values ranging from 10⁸ to 10¹¹ Ω/cm², demonstrating excellent corrosion protection. To complement the study, mechanical tests were conducted using commercial coatings. Additionally, in vitro cytotoxicity tests using human skin cells (HaCaT) showed cell viability and proliferation comparable to control samples, confirming low toxicity. These results validate the potential of Pinus radiata bark wax-based coatings as a multifunctional, cost-effective, and environmentally friendly alternative to conventional anticorrosive solutions.

6.5. Development of Innovative Antifouling Materials for Marine Environment Applications

• Katherine andrea Delgado

• Universidad Bernardo O’Higgins, Santiago 8370993, Chile

Marine biofouling is a phenomenon in which unwanted organisms adhere to submerged surfaces, altering their chemical, physical, and functional properties. This process begins with forming a biofilm, known as microfouling, composed of bacteria that modify the affected surface. Subsequently, larger organisms such as algae, mollusks, and crustaceans settle on the biofilm, intensifying the deterioration in a process referred to as macrofouling.

In response to this challenge, developing polymers with antifouling properties represents a disruptive advance in managing marine biofouling. These innovative materials integrate graphite oxide (GrO) nanomaterials and confer surfaces with properties that effectively inhibit organism adhesion. Polymers modified with 5% GrO have proven to be highly effective, achieving up to a 305% reduction in organism accumulation compared to untreated surfaces after one year of exposure to real marine conditions, demonstrating their durability and resistance in adverse environments.

These polymeric matrices excel in their capacity to combat biofouling and their remarkable versatility across various industrial applications. In the renewable energy sector, their integration into offshore wind turbines and tidal energy platforms would enhance operational efficiency by significantly reducing maintenance costs and efforts associated with the accumulation of marine organisms. In sustainable aquaculture, these matrices could extend the lifespan of nets and cultivation cages, considerably lowering cleaning and biofouling management costs. In maritime transportation, their application to ship hulls would optimize fuel consumption by reducing water friction, contributing to carbon emission reductions, and promoting more sustainable operations. Finally, these surfaces protect research equipment and sensors in ocean exploration, ensuring their functionality over extended periods in extreme and challenging accumulating conditions.

Developing these technologies is essential to addressing future challenges in marine environments. By combining operational efficiency and versatility, these polymeric matrices are positioned as a fundamental component in the design of advanced materials, with the potential to transform maritime industries and related sectors.

6.6. Evaluation of the Corrosion Behavior of Low-Temperature Nitrided AISI 316L Austenitic Stainless Steel

• Francesca Borgioli

• Department of Industrial Engineering (DIEF), University of Florence, Via S. Marta 3, 50139 Florence, Italy

Introduction: Low-temperature nitriding of austenitic stainless steels allows for the formation of a supersaturated solid solution of nitrogen in the austenite lattice (expanded austenite or S-phase), while inhibiting the precipitation of Cr nitrides. The corrosion behavior of the nitrided layers depends on their microstructure and phase composition, as well as on the environment characteristics. The testing conditions can also play a role, as observed when the repassivation characteristics are assessed. The aim of the present study is to evaluate the corrosion behavior of low-temperature nitrided AISI 316L austenitic stainless steel using different electrochemical techniques and, in particular, to assess the repassivation capability in NaCl solution.

Methods: AISI 316L samples were glow-discharge-nitrided at 380 °C, under 130 Pa, for 5 h. Microstructure, phase composition, and surface microhardness were assessed. Corrosion behavior was evaluated in 5 wt.% NaCl aerated solution using different electrochemical techniques (electrochemical impedance spectroscopy (EIS), cyclic potentodynamic, and galvanostatic techniques).

Results: The hardened nitrided layers mainly consisted of expanded austenite. EIS analysis showed that nitrided samples had higher impedance values than the untreated steel. The cyclic potentiodynamic test results were affected by testing conditions. Corrosion potential and pitting potential values of the nitrided samples were higher than those of the untreated ones, but the nitrided samples were not capable of repassivating. On the contrary, when the galvanostatic technique was employed, the potential value, below which localized corrosion phenomena did not occur, was usually higher than the corrosion potential of the untreated alloy, suggesting that repassivation could occur.

Conclusions: The experimental results suggested that the repassivation capability of nitrided AISI 316L austenitic stainless steel was particularly sensitive to the extent of damage. When minor damage occurred, from, for example, using the galvanostatic technique, high corrosion resistance was maintained. However, fairly significant corrosion damage, such as that occurring in cyclic potentiodynamic tests, hindered repassivation.

6.7. High-Temperature Fatigue Testing of Turbine Blades

• Mateusz Kopec

• Institute of Fundamental Technological Research, Polish Academy of Sciences, Pawińskiego 5B, 02-106 Warsaw, Poland

This study introduces an innovative experimental setup for high-temperature fatigue testing of full-scale nickel-based turbine blades protected with aluminide coating, aiming to replicate operational conditions and enhance service life predictions. A patented grip system was developed to enable precise determination of the S–N curve and hysteresis loop evolution under simulated extreme conditions. The blades were tested at 950 °C with cyclic bending loads ranging from 5.2 kN to 6.6 kN at a frequency of 10 Hz. A preliminary bending test established the force–displacement relationship, providing critical input for fatigue testing parameters. The setup integrates an Inconel alloy testing stand with an induction heating system, ensuring uniform temperature distribution with deviations limited to ±3 °C. Advanced monitoring techniques allowed for high-frequency data acquisition, facilitating the capture of force-displacement relations and hysteresis loop development. Results revealed distinct behavioral transitions, including elastic responses and plastic deformations at higher force amplitudes, contributing to a comprehensive understanding of fatigue-induced damage mechanisms. Key findings underscore the effectiveness of this methodology in capturing the complex mechanical responses of turbine blades under high-temperature cyclic loading. The proposed setup addresses the limitations of conventional standardized specimen testing by enabling full-scale component evaluation, thus offering significant advancements in material performance assessment for aerospace applications. This work represents a critical step toward optimizing the design and durability of high-temperature components, aligning with the demanding requirements of modern turbine technologies.

6.8. Impact of Surface Treatment and Surface Condition on Fatigue and Fracture Resistance of Materials in Hot Forging of Aluminum Alloy Parts

• Erik Calvo-García, Marco González-Longueira, Aida Badaoui, Antonio Riveiro and Rafael Comesaña

• CINTECX, LaserON Research Group, Universidade de Vigo, 36310 Vigo, Spain

Introduction: High-performance steels have multiple applications; they are frequently used in tools for the manufacture of aluminium alloy parts, for instance, injection moulds, extrusion and stamping tools, or in forging dies. These materials provide high mechanical strength and high wear resistance during high-temperature operation. Their heat treatment determines the compromise between fracture toughness and hardness for each application. Thus, the degree of quenching and tempering is frequently selected based on these parameters. However, the mechanical durability of these materials is very sensitive to their surface condition and contact with potentially corrosive fluids. On the other hand, in the case of aluminium parts manufactured by this process, the use of surface treatments is very common in improving the finished component’s performance. These treatments may or may not point to improvement in mechanical durability. Nevertheless, they can be a determining factor on the fatigue resistance of the manufactured component.

Methods: For this work, the effect of the surface state, the contact with operational fluids, and different surface treatments on fatigue resistance has been studied experimentally. The fundamental materials of the hot forging process, both the high-performance steels used for the dies, and the aluminium alloys of the manufactured components, have been studied. Surface modification treatments such as shot peening and anodisation have been tested, and their influence on the mechanical durability was assessed.

Results and Conclusions: The results of this work confirm the sensitivity of fatigue resistance, both in low-cycle and high-cycle regimes, for high-performance steels when exposed to aggressive environments that can generate surface corrosion. Likewise, the behaviours of high-strength aluminium alloys, when subjected to surface finishing treatments for increasing mechanical durability and corrosion resistance, such as shot peening and anodisation, respectively, are presented.

6.9. Inter-Splat Boundary Effect on Cold-Sprayed Nickel-Based Alloy Coatings Through Mechanical and Corrosion Performance

• Neelima Devi G and S Kumar

• International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), Hyderabad–500 005, India

Cold spraying is a prominent solid-state deposition technique for depositing nickel-based alloy coatings without causing microstructural changes due to its lower operating temperatures than other thermal spray processes. However, depositing nickel-based coatings via cold spraying is more challenging than other metals due to their thermo-mechanical behavior. Thermal sensitivity (m), a constant parameter in the Johnson–Cook (JC) plasticity model, is used to estimate the flow stress of plastically deformed materials at higher strain rates. Since nickel-based alloys such as NiCr, IN625, and IN718 alloys exhibit high thermal sensitivity (m > 1), their deposition becomes easier at elevated particle temperatures, particularly when air is used as a process gas instead of more expensive gases like nitrogen or helium. In this work, higher particle temperatures were achieved by increasing the stagnation temperature and the nozzle convergent length. In cold-sprayed coatings, corrosion liquids percolate through unbonded inter-splat boundaries, significantly affecting the corrosion rate. These unbonded boundaries also contribute to a reduction in the elastic modulus. Hence, this study examines the effect of particle temperature on the inter-splat bonding percentage of as-sprayed and heat-treated coatings and its impact on oxidation, corrosion resistance, and elastic modulus. The inter-splat bonding is estimated through numerical simulation using ABAQUS explicit code. The results demonstrate that increasing the particle temperature enhances the oxidation resistance for NiCr coatings. The parabolic oxidation rate is constant for coatings deposited using air as the process gas, comparable to that obtained from other thermal spray techniques (such as Arc spray and HVOF). Corrosion resistance is higher and equivalent to the bulk Inconel after the heat treatment of the coating, which is deposited at a higher stagnation temperature. The elastic modulus was estimated through numerical simulation, and nanoindentation was validated. The obtained results demonstrated that the estimated modulus is improved with inter-splat bonding percentage.

6.10. Performance of Alternative Biowax Powders Replacing PTFE Fillers in Bio-Based Epoxy Coatings

• Pieter Samyn

• SIRRIS, 3001 Leuven, Belgium

In view of sustainable-by-design issues, there is an urgent need to replace harmful coating ingredients with more ecological, non-toxic alternatives derived from bio-based resources. In particular, fluorine derivatives such as polytetrafluoroethylene (PTFE) are frequently applied in coatings because of their versatile role in rendering hydrophobicity and lubrication. In this research, a screening study is presented on the performance of alternative biowaxes derived from different natural sources, when used in protective coating applications. Micronized powders from carnauba wax, rapeseed wax, rice bran wax, palm oil wax, or sunflower wax are added into epoxy clear-coat formulations. When dispersed into a bio-based epoxy from epoxidized flaxseed oil and a proprietary acid hardener, the thermal curing process significantly affects the efficiency of the biowax additives. In concentration ranges of 1 to 10 wt. %, it was observed that the biowaxes consequently present higher hardness and hydrophobicity as coatings as compared to the PTFE additives, while similar abrasive resistance and scratch resistance could be obtained. Moreover, the proprietary mixture ratios of biowax to PTFE powders provide synergistic effects. The granulometry of the biowax powders is a crucial parameter as smaller micrometer grain sizes improve dispersibility in the coating. The mechanistic effects of micronized biowax powder in the epoxy coating are further evaluated through spectroscopic analysis, indicating their interference with the curing process of the epoxy coating.

6.11. Sealing PVD Coating Defects with Ti-O ALD Layers

• Zoran Bobić ¹, Lazar Kovačević ¹, Vladimir Terek ¹, Miha Čekada ², Aljaž Drnovšek ², Peter Rodič ², Atilla Csik ³ and Pal Terek ¹

¹ 

University of Novi Sad, Faculty of Technical Sciences, Trg Dositeja Obradovića 6, 21000 Novi Sad, Serbia

² 

Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia

³ 

Institute for Nuclear Research, Bem tér 18/c, 4026 Debrecen, Hungary

Previous investigations have revealed that Atomic Layer Deposition (ALD) layers on Physical Vapor Deposition (PVD) coatings lead to pinhole defect sealing, which results in improved coating corrosion properties. However, despite this, the influence of PVD defect size on the sealing efficiency of ALD layers remains poorly determined. This study aimed to evaluate the corrosion properties of hybrid PVD/ALD layers with a focus on how the influence of PVD defect size affects the sealing efficiency of ALD layers. The corrosion resistance of PVD TiN coatings and TiN combined with ALD Ti-O layers (amorphous and anatase phases) was investigated in phosphate-buffered saline solution (PBS). Corrosion experiments were conducted on circular areas of 4 mm in diameter using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PD) measurements. Confocal and tactile profilometry were performed before and after the corrosion tests to identify and quantify the PVD coating growth defects. To examine the thickness and uniformity of the ALD layers, scanning electron microscopy (SEM) was utilized on cross-sections of PVD defects prepared by focused-ion beam (FIB). The results revealed that the increased number of protrusion defects, with heights exceeding 2 µm, correlates with a decrease in impedance for PVD-coated samples. The deposition of ALD layers significantly improved the corrosion resistance of samples. Cross-sectional FIB-SEM analysis confirmed uniform coverage by the ALD layer without visible cracks across all investigated ALD layers. However, corrosion tests revealed that the amorphous TiO₂ ALD layer exhibited superior PVD defect-sealing efficiency compared to the anatase TiO₂ layer. This suggests that the presence of grain boundaries in the anatase TiO₂ ALD layer contributes to its lower sealing efficiency. The application of ALD layers on PVD-coated samples, by forming a hybrid coating, offers a promising solution for applications requiring enhanced corrosion resistance alongside adequate surface mechanical properties.

6.12. The Effect of Surface Roughness on Scratch Adhesion and Tribological Behavior of PVD Hard Coatings with Different Layer Designs

• Pal Terek ¹, Lazar Kovačević ¹, Vladimir Terek ¹, Zoran Bobić ¹, Branko Škorić ¹, Miha Čekada ² and Aljaž Drnovšek ²

¹ 

University of Novi Sad, Faculty of Technical Sciences, Trg Dositeja Obradovića 6, 21000 Novi Sad, Serbia

² 

Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia

The surfaces of industrial components intended to be coated with wear-resistant coatings are frequently not polished. On the contrary, during the coating development, its properties are always evaluated on highly polished surfaces. These differences in surface conditions may lead to erroneous estimation of the future coated part properties. Contemporary hard coatings that are used for enhancing tribological performance are produced with different layer designs, namely single layers, multi layers, and nanolayers. However, their performance on surfaces with different roughnesses is addressed to a minimal extent in the literature. This investigation examined three kinds of coatings of different layer designs deposited by magnetron sputtering, namely TiAlN (single layer), TiAlN/CNx (dual layer) and AlTiN/TiN (nanolayer) coating. Coatings were deposited on steel substrates with four degrees of roughness. The coatings’ adhesion was evaluated by scratch test performed parallel and perpendicular to the grinding marks. The tribological behavior of the coatings was assessed by dry-reciprocating the sliding test against an Al₂O₃ counter ball. All samples were evaluated before and after the experiments through 3D tactile profilometry, confocal optical microscopy, and energy dispersive spectroscopy. In all cases, the surface roughness of the samples increased after the coating deposition, and these surfaces belong to the range of fine surface finishes, namely Sa = 12–545 nm. Within the investigated range of surface roughness, coatings with different layer designs behaved differently according to changes in surface roughness. TiAlN and TiAlN/CNx coatings showed no dependence on scratch adhesion or tribological behavior on surface roughness. For the roughest surface, a reduction in adhesion and an increase in wear rate were both observed. The AlTiN/TiN nanolayer coating displayed the largest sensitivity of adhesion on roughness and scratching direction. The coefficient of friction and wear rate of AlTiN/TiN coating increased when the roughness was larger than Sa ≈ 100 nm. This indicates that future investigations should cover a wider range of nanolayer coatings.

6.13. The Impact of Oxidative Amine Degradation on the Corrosion Behavior of 304L and 316L Stainless Steels in MEA Solutions Containing SOx and NOx Contaminants

• Eleni Lamprou ¹, Fani Stergioudi ¹, Nikolaos Michailidis ¹, Evie Nessi ², Athanasios I. Papadopoulos ² and Panagiotis Seferlis ³

¹ 

Physical Metallurgy Laboratory, School of Mechanical Engineering, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece

² 

Chemical Process and Energy Resources Institute, Centre for Research and Technology Hellas, 57001 Thermi, Greece

³ 

Laboratory of Machine Dynamics, School of Mechanical Engineering, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece

Post-combustion CO₂ capture using aqueous amine solutions has gained significant popularity in recent years, owing to their exceptional absorption capacity, rapid reaction kinetics, and ability to regenerate efficiently. However, a major challenge lies in the corrosive nature of amines after reacting with CO₂, which can lead to significant operational issues in process equipment. Beyond CO₂, the oxidative degradation of amine solvents further influences corrosion. This degradation is accelerated by oxidative agents, such as O₂, SOx, and NOx impurities in flue gas, which interact with amine solutions to form various degradation by-products.

This study focused on investigating the corrosion behavior of 316L and 304L stainless steels (SS316L and SS304L)—widely used in carbon-dioxide capture units—when exposed to both degraded and non-degraded MEA aqueous amine solutions containing SOx and NOx pollutants, under both CO₂-loaded and unloaded conditions. The research assesses the impact of MEA degradation on the corrosion characteristics of these stainless steels, using Potentiodynamic Polarization and Electrochemical Impedance Spectroscopy. Scanning electron microscopy (SEM) was used to gain further insights into corrosion mechanism.

The results revealed that the degradation of the amine solutions, whether CO₂-loaded or unloaded, promoted the corrosion in both stainless steels. Corrosion rates were higher in degraded solutions compared to non-degraded ones, indicating reduced corrosion resistance. This was also verified by the lower total impedance values observed in Bode diagrams.

Funding: This work has received funding from the European Union’s Horizon Europe research and innovation program under grant agreement No. 101075727. The views and opinions expressed are, however, those of the author(s) only and do not necessarily reflect those of the European Union or European Climate, Infrastructure and Environment Executive Agency (CINEA). Neither the European Union nor the granting authority can be held responsible for them.

6.14. Water Vapour Transmission Properties of Waterborne Coatings—Effect of Selected Parameters

• Małgorzata Gnus

• Łukasiewicz Research Network—Institute of Polymer Materials, M. Skłodowskiej Curie 55 Street, 87-100 Toruń, Poland

Water-based coatings materials, due to their desirable properties such as very good resistance to weather conditions and flexibility as well as easy application, are used for both decorative and protective purposes. The ability of the coatings to transport water can effect fungi growth, loss of adhesion, or the penetration of aggressive ions from rain into the substrate. Therefore, determining the water transport properties of water by paints is a key point in determining their protective properties.

This study investigated the effects of preparation, conditioning, and testing methodologies on the water vapour permeability properties of waterborne coatings. The study was divided into two parts. In the first part, the influence of the binder content of the paint product, the film thickness, and the presence of different substrates on the water vapour permeability values obtained was determined. In the second part, the influence of conditioning and testing methods was investigated. The conditioning method was selected based on the target use of the coating (indoor/outdoor), in accordance with the instructions in the PN-EN ISO 7783:2018-11 standard. However, due to the possibility of applying outdoor paints indoors, they were conditioned using both methods. Since the standard does not indicate how to select a test method for each group of prepared coatings, wet and dry cup methods were performed.

The results obtained show that the water vapor transmission rate decreases with increasing binder content, and the observed differences are greater for thicker coatings. The water vapor transmission through the coating on the substrate depends on the interaction between them. The coating conditioning method has the greatest influence on its ability to transport water; therefore, to determine the protective properties of the coating, it is important to choose test conditions that best represent the actual conditions in which the coating will be used.

7. Novel Methods/Techniques for Coating Deposition and Characterization

7.1. Aluminum-Based Electrospark Alloyed Coatings

• Oksana Haponova ¹, Nataliia Tarelnyk ², Gennadii Laponog ³ and Viktor Okhrimenko ³

¹ 

Department of Experimental Mechanics, Institute of Fundamental Technological Research Polish Academy of Sciences, Pawińskiego 5B, 02-106 Warsaw, Poland; 2-Applied Material Science and Technology of Constructional Materials Department, Sumy State Uni

² 

Technical Systems Design Department, Sumy National Agrarian University, H. Kondratiieva 160, 40021 Sumy, Ukraine

³ 

Applied Material Science and Technology of Constructional Materials Department, Sumy State University, Kharkivska 116, 40007 Sumy, Ukraine

The aluminised coatings obtained on steels by the method of electrospark alloying (ESA) are investigated. Carbon steels were tested for the influence of the discharge energy and productivity (classic regimes, 2- and 4-fold reduction values) of the treatment process on the thickness of the hardened layer, its microhardness, continuity and surface roughness. Optical and scanning metallography, X-ray diffraction analysis, micro-X-ray diffraction analysis and micro hardness distribution tests were used for the study. Metallographic analysis showed that the structure of ESA coatings is layered, with a white layer not detectable in the reagent, diffusion zone or the substrate. The chemical and phase composition of the coating change when the discharge energy is increased during ESA. At low discharge energies, a layer consisting mainly of a-Fe and aluminium oxides is formed; as the discharge energy rises, the layer consists of iron and aluminium intermetallics and free aluminium. If the ESA productivity is reduced by factor 2, the thickness of the “white” layer increases to 75–110 µm, and its microhardness to 7450 MPa; the continuity of the coating approaches 100%. The deterioration of the coating quality parameters and the increase in roughness are due to a 4-fold decrease in process productivity. In order to improve hardening technology, it is important to study the influence of the energy parameters of ESA and the alloying time (‘productivity’) of the process. Aluminum-based coatings produced by the proposed ESA methods are recommended for use at high temperature.

7.2. Analytical Spectroscopic Characterization of Green Chitosan/Copper Nanocomposites for Food Packaging Applications

• Danilo d’Agostino ^1,2, Luigi Gentile ^1,2, Margherita Izzi ^1,2, Simona Marianna Sanzani ³, Ornella Incerti ³, Nicola Cioffi ^1,2 and Maria Chiara Sportelli ^1,2

¹ 

Department of Chemistry, University of Bari Aldo Moro, via E. Orabona 4, 70126-Bari, Italy

² 

Bari Unit of CSGI consortium, University of Bari Aldo Moro, via E. Orabona, 4, 70126-Bari, Italy

³ 

Department of Soil, Plant and Food Sciences, University of Bari Aldo Moro, via Amendola 165/A, 70126-Bari, Italy

Introduction: Reducing agrifood waste has become an important goal, considering that up to 50% of total production is lost due to contamination by harmful microorganisms. In this context, controlling the interface between food products and the external environment can be a powerful tool to prevent waste. The aim of this study was to produce a bio-based and biodegradable food packaging material loaded with copper particles, which act as a reservoir of cupric ions.

Methods: A green one-pot approach was used to synthesize copper particles using poly(N-vinylpyrrolidone) (PVP) as a capping agent (Cu@PVP), preventing aggregation through steric hindrance and eliminating the need for an inert atmosphere. The influence of PVP and reductant concentrations, as well as reaction time, on the oxidation state of copper phase, synthesis kinetics, and particle size was investigated by varying each of these parameters individually. Optimal conditions were identified to obtain an average particle diameter above 200 nm, while minimizing reagent and time consumption, to prevent nano-cytotoxicity effects. After a purification step, the Cu@PVP particles were suspended in ethanol and embedded in a chitosan (CS) polymeric matrix.

Results: Composite films were obtained by solvent casting. The polymer solution concentration was adjusted to maintain good rheological properties even in the presence of inorganic particles. Torsional rheology and water uptake measurements were performed to assess the mechanical behavior of the self-standing films obtained after solvent evaporation. The antimicrobial capabilities were demonstrated by ionic Cu²⁺ release kinetics, and in vitro by growth inhibition of three different model fungi responsible for agrifood spoilage.

Conclusions: This innovative material could be used for the production of biodegradable bags and envelopes destined for the storage of fruits and vegetables, extending the shelf-life of these horticultural products.

7.3. Carbon/Fiber-Reinforced ABS and Nanodiamond-Reinforced PLA 3D-Printed Hierarchical Honeycomb and Spiderweb Structures

• Michel Theodor Mansour, Vasileios Papageorgiou, Apostolos Linaroudis, Georgios Skordaris and Gabriel Mansour

• Department of Mechanical Engineering, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece

The investigation and construction of complex hierarchical structures from advanced composite materials through various additive manufacturing processes is developing rapidly worldwide and plays a particularly crucial role in the manufacturing and industrial sector. One of the most popular 3D printing techniques is Fused Filament Fabrication (FFF), which utilizes thermoplastic filaments as printing material. The mediocre mechanical performance of thermoplastic polymers has resulted in the rapid research and progress of advanced nanocomposite materials with the aim of improving the mechanical properties of complex structures. The objective of the current study is firstly to design and manufacture FFF 3D-printed hierarchical honeycomb and spiderweb constructs, using two advanced composite materials, polylactic acid reinforced with nanodiamonds (PLA/uD) and acrylonitrile butadiene styrene with carbon fibers as reinforcement (ABS/CF). At the second stage, there was an examination of the mechanical performance of these involute structures under experimental and theoretical tests. In particular, the compression behavior of the fabricated hierarchical honeycombs and spiderwebs was assessed by experiments along with finite element analysis (FEA) simulations. According to the results, the hierarchical cellular structures exhibited enhanced mechanical properties in comparison with the spiderweb structures. Specifically, augmented stiffness and compressive strength were observed. In addition, the increase of hierarchy in the honeycomb structures resulted in an improvement in the mechanical behavior in contrast to the spiderweb constructs. Finally, the convergence between the experimental and theoretical results was quite good for both hierarchical structures and materials.

7.4. Design of Strengthened and Toughened Thin Film Materials Based on Nano-Ordered Structures

• Kan Zhang

• Department of Materials Science, Jilin University, Changchun 130012, China

In the study of hard protective coating materials, the pursuit of higher hardness often comes at the expense of reduced toughness, leading to brittle fracture failure. To address this challenge, we propose a nanoscale structural regulation strategy from the perspective of material microstructure design to resolve the trade-off between hardness and toughness. Specifically, we employed a layered deposition process to activate the “solid-state dewetting” method, successfully fabricating a 3D coherent TaC@Ta nano-core-shell micro/nano-structured coating. This structure effectively suppresses interfacial crack initiation from three dimensions and overcomes the limitations of thermal-driven phase separation methods on toughening metals, thereby avoiding hardness deterioration caused by toughening efforts. Next, we proposed an atomic-scale tailoring strategy using “high negative mixing enthalpy + high lattice distortion” to induce localized disordered clusters. This approach transforms the topologically ordered structure of transition-metal high-entropy alloys into a novel high-entropy paracrystalline structure, with sub-nanoscale sub-crystals as structural units. This innovation achieved a 100% increase in hardness and a 69.2% increase in compressive strength, along with a significant enhancement in ultimate plastic deformation capacity. Furthermore, we developed a vertically aligned “bamboo-like” nanocolumnar copper coating material reinforced by an amorphous boron framework through bottom-up growth using magnetron co-sputtering. This structure achieved an indentation hardness of 10.8 GPa while maintaining excellent strength (yield strength ~1.36 GPa, flow stress ~2.58 GPa) and ductility (failure strain exceeding 50%). This series of works demonstrates the simultaneous enhancement of hardness, strength, and toughness in coating materials through the design of 3D coherent, nanoscale sub-crystalline structures, and “bamboo-like” structures. These findings provide new insights and approaches for the microstructural design and fabrication of toughened structural coating materials.

7.5. Energydispersive X-Ray (EDX) Analysis of Spin-Coated Zinc Oxide Nanoparticles by (Al, F) Co-Doping

• Fransisco Konan

¹ 

Ecole Normale Supérieure (ENS) Abidjan, Laboratoire des Sciences Physiques Fondamentales et Appliquées, 08 BP 10 Abidjan 08, Côte d’Ivoire

² 

Laboratoire de Virologie, Oncologie, Biosciences, Écotoxicologie, Environnement et Énergies Nouvelles (LVOBEEN), Groupe Matériaux, Énergie, Eau, Modélisation et Développement Durable (GMEEM& DD), FSTM, Hassan II University of Casablanca (UH2C), BP 146 Moh

Energy-dispersive X-ray (EDX) analysis is an elemental analysis technique associated with Field Scanning Electron Microscopy (FESEM); it is frequently used in material science and engineering. EDX analysis enables both qualitative and quantitative studies to be carried out for a variety of applications. In this study, aluminum and fluorine (Al, F) co-doped zinc oxide nanoparticles were grown using the sol–gel route via the spin-coating method with various (Al, F) contents (1 at.%, 1 at.%), (3 at.%, 3 at.%), (5 at.%, 5 at.%), and (7 at.%, 7 at.%). The as-grown samples were characterized by energy-dispersive X-ray (EDX) and Scanning Electron Microscopy (FESEM) techniques. The results revealed that the nanoparticles have uniform morphology and hexagonal structure with a homogenous distribution. We can observe the incorporation of Al and F into the zinc oxide lattice when (Al, F) content is (1 at.%, 1 at.%) and (3 at.%, 3 at.%) while the presence of Al and F peaks in the spectrum of EDX results was demonstrated in the two dopants with (Al, F) content (5 at.%, 5 at.%) and (7 at.%, 7 at.%), indicating the film’s microstructure quality degradation. Grain sizes ranged from 10 to 13 nm. In conclusion, simultaneous co-doping improved the microstructure of FAZO nanoparticles when the (Al, F) content was (1 at.%, 1 at.%) and (3 at.%, 3 at.%); thus, EDX can be considered as a useful technique in all research works that require element determination.

7.6. Enhancing Road Safety with Smart Road Marking Paints: Self-Cleaning and Thermochromic Capabilities

• Orlando Lima Jr. ^1,2, Iran Rocha Segundo ², Laura Mazzoni ³, Elisabete Freitas ¹ and Joaquim Carneiro ²

¹ 

Department of Civil Engineering, ISISE, ARISE, University of Minho, 4800-058 Guimarães, Portugal

² 

Centre of Physics of Minho and Porto Universities (CF-UM-UP), Azurém Campus, University of Minho, 4800-058 Guimarães, Portugal

³ 

Department of Transportation Engineering, University of São Paulo, 13566-590 São Paulo, Brazil

Road markings (RMs) are infrastructure elements positioned to guide road users, regulate traffic, and enhance road safety. Significant advances in materials technology, such as the use of several types of paints and retroreflective materials, have contributed to improving the durability and day and night visibility of RMs. However, challenges in this field still remain, and recent developments have focused on using smart materials to incorporate innovative functionalities into RMs. Notable examples include semiconductors, which can photo-oxidize surface pollutants and provide self-cleaning properties, and thermochromic materials, capable of changing color at specific transition temperatures (TTs), offering visual feedback on pavement surface conditions. In this context, the objective of this study was to develop RM paints with self-cleaning properties (to enhance visibility and durability) and thermochromic properties (to indicate the potential presence of ice or snow on asphalt pavements). For the self-cleaning RM paint, different amounts of TiO₂ were incorporated into a water-based acrylic RM paint. The self-cleaning ability was assessed using CIELAB colorimetry to monitor the degradation of a model pollutant under UV light irradiation. For the thermochromic RM paint, thermocapsules with a TT equal to the freezing point of water (0 °C) were incorporated into a water-based acrylic RM paint. The thermochromic behavior was analyzed by the CIELAB system while the paints were exposed to negative and positive temperatures. The results showed that the self-cleaning RM paint achieved pollutant degradation capacity up to 3.2 times higher than the reference paint. The thermochromic RM paint demonstrated the ability to change to a pinkish color at temperatures below 0 °C, reversibly returning to the original white color at positive temperatures. Both properties showed potential to enhance road safety by improving visibility and providing visual feedback on usage conditions.

7.7. Enzymatic Grafting as a Method for Wood Coating

• Diego Moldes ¹, Susana Gouveia ², Mari Carmen Fernández-Costas ², Daniel Filgueira ² and Cristian Bolaño ³

¹ 

University of Vigo

² 

Department of Chemical Engineering. Universidade de Vigo

³ 

Norwegian University of Life Sciences: NMBU

Wood is a natural material with structural and aesthetic roles in indoor and outdoor constructions. Wood treatments are performed to improve the material’s natural drawbacks, such as biodeterioration, water absorption, microbial colonization, and flame sensitivity.

Conventional wood treatments, especially when wood is used outdoors, must normally be repeated regularly, because the compounds that are used are leached away, since a stable link between the wood and chemicals added is lacking. This leaching may also produce environmental pollution.

To improve the stability of wood treatments by promoting a stable coating, a new biotech method is proposed: the use of laccase to stably graft chemical compounds onto a wood surface. Laccase is an enzyme that can oxidize phenolic compounds to produce chemical radicals that may then link to a polymer chain, such as wood components, by means of covalent bonding. If the phenolic compounds also contain another functionality, it could be conferred to the wood after the grafting. This principle has been used to link several phenolic compounds to wood samples and, therefore, to modify their chemical composition and properties.

Using this biotechnological tool, a range of wood treatments were tested and analysed: the modification of the surface composition of wood, the hydrophobization of wood surfaces, the grafting of flame retardants, the design of new wood durability treatments, etc.

This new method opens up new possibilities in wood treatments by means of a mild and sustainable process.

7.8. High-Performance Bi-Layer TiO₂ Structures in DSSC Application

• Norazlina Ahmad ¹, Azman Talib ¹ and Fariza Mohammad ²

¹ 

Department of Electrical Engineering, Politeknik Mersing, Johor, Malaysia

² 

Faculty of Electrical and Electronic Engineering, Universiti Tun Hussein Onn, Johor, Malaysia

A two-step hydrothermal process was employed to fabricate a highly efficient TiO₂ film. In the first hydrothermal step, a bi-layer structure was synthesized, consisting of well-aligned one-dimensional (1D) rods and three-dimensional (3D) flower-like structures on an FTO substrate. Both morphologies exhibited a robust rutile phase, which is believed to provide direct conductive pathways and reduce electron-hole recombination. However, the compact nature of the bi-layer TiO₂ structure limited dye absorption, resulting in suboptimal performance of Dye-Sensitized Solar Cells (DSSCs). To address this issue, an etching treatment using a highly acidic hydrochloric acid (HCl) medium was implemented as the second hydrothermal step. The samples’ morphology was carried out using field emission scanning electron microscopy (FE-SEM). A 4Point Probe (Signatone Pro4-440N) was connected to the source meter to ascertain the resistivity properties of the samples. The etching treatment effectively increased the surface area of the TiO₂ bi-layer, facilitating improvements in DSSC performance. The etching process transformed the morphology into a needle-like structure as revealed by FESEM images, while the reduction in electrical resistivity indicated a significant enhancement in the material’s properties. The etched sample demonstrated superior performance, achieving a power energy conversion (PEC) efficiency of 10.05%, compared to 6.41% for the non-etched sample.

7.9. Optical and Thermal Behavior of Phase-Change Fibers for Enhancing Thermal Comfort

• José Monteiro ¹, Nathalia Hammes ^2,3, Iran Rocha Segundo ², Helena Prado Felgueiras ³, Maria Manuela Silva ⁴, Manuel Filipe Costa ⁵ and Joaquim Carneiro ²

¹ 

Earth Sciences Department of the University of Minho, Gualtar Campus, University of Minho, R. da Universidade, 4710-057 Braga, Portugal

² 

Centre of Physics of Minho and Porto Universities (CF-UM-UP), Azurém Campus, University of Minho, Av. da Universidade, 4800-058 Guimarães, Portugal

³ 

Centre for Textile Science and Technology (2C2T-UMinho), Azurém Campus, University of Minho, Av. da Universidade, 4800-058 Guimarães, Portugal

⁴ 

Centre of Chemistry of University of Minho (CQ-UMinho), Gualtar Campus, University of Minho, R. da Universidade, 4710-057 Braga, Portugal

⁵ 

Centre of Physics of Minho and Porto Universities (CF-UM-UP), Gualtar Campus, University of Minho, R. da Universidade, 4710-057 Braga, Portugal

Over the years, climate change has been intensifying global temperature fluctuations, bringing significant heatwaves to certain parts of the planet and vastly contributing to the Urban Heat Island (UHI) effect, while other parts of the world have experienced extreme cold spells. These global changes have impacted cities, leading to significant thermal discomfort and rising energy demands in heating and cooling. Developing sustainable solutions for these rising challenges has become crucial for enhancing urban living conditions and achieving good energy efficiency while keeping the population comfortable. One of the most promising solutions that has arisen in the last couple of years has been the incorporation of Phase-Change Materials (PCMs) into Civil Engineering materials. These materials can be encapsulated into Phase-Change Fibers (PCFs), which represent a novel technology in the literature. These PCFs utilize the latent heat principle, absorbing or releasing energy during phase transitions to maintain a stable temperature. In this context, this study produced PCFs via wet-spinning with commercial Cellulose Acetate (Mn 30,000) and polyethylene glycol (PEG 400 and 600). The fibers’ structures were optically evaluated using Bright-Field microscopy and Attenuated Total Reflectance–Fourier Transform Infrared Spectroscopy (ATR-FTIR). The first test confirmed the PCFs’ coaxial morphology and the proper PEG encapsulation within the CA sheath. Through ATR-FTIR, it was possible to confirm the key functional groups of the virgin materials and their successful integration during the production of the fibers. Thermal testing was conducted through Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). PCFs incorporating PEG 400 and PEG 600 demonstrated phase-change temperatures of around −4 °C and 12 °C and an enthalpy of 26 J/g and 29 J/g, respectively, showing great potential applications for different climates. The degradation temperatures were 234 °C and 300 °C, ensuring their resilience for integration into construction materials such as cementitious materials.

7.10. Recent Advances in Tool Coatings and Materials for Superior Performance in Machining Nickel-Based Alloys

• Kerolina Sonowal and Partha Protim Borthakur

• Department of Mechanical Engineering, Dibrugarh University, Assam 786004, India

Nickel-based alloys, including Inconel 718 and alloy 625, are indispensable in industries such as aerospace, marine, and nuclear energy due to their exceptional mechanical strength, high-temperature performance, and corrosion resistance. Despite their advantages, these alloys present significant challenges during machining owing to their hardness, and low thermal conductivity. To address these issues, advancements in tool coatings and materials have become critical, driving innovation in machining technologies. Coatings such as Titanium Aluminum Nitride (TiAlN) and Titanium Silicon Nitride (TiSiN) are recognized for their high thermal stability, hardness, and oxidation resistance, making them ideal for high-speed and elevated-temperature machining. Nano-Composite Coating (nACo) provides enhanced wear resistance, while Titanium Nitride (TiN) and Titanium Carbonitride (TiCN) offer anti-friction properties and toughness, respectively. Aluminum Oxide (Al₂O₃) delivers superior thermal stability and resistance to abrasive wear. Advanced solutions include multilayer coatings like TiAlN/TiN, which combine thermal resistance and toughness, and doped Ti₃AlN coatings enhanced with chromium or vanadium to improve hardness and machining efficiency. Tool materials have also seen significant advancements. Cemented carbides remain widely used due to their balance of hardness and toughness, while ceramic tools offer exceptional thermal stability for high-speed operations. Polycrystalline Cubic Boron Nitride (PCBN) excels in machining hardened alloys, and Polycrystalline Diamond (PCD) extends tool life significantly, particularly in milling applications. Nanoscale structured tools, often combined with optimized coatings, provide enhanced cutting efficiency. Tool wear caused by the hardness and work-hardening nature of nickel-based alloys necessitates robust coatings like TiAlN and multilayer systems to maintain thermal and mechanical stability. The integration of innovative coatings and tool materials has significantly improved the machinability of nickel-based alloys. Technologies such as TiAlN, TiSiN, and advanced multilayer systems, coupled with cutting-edge materials like PCD, continue to enhance wear resistance, reduce cutting forces, and ensure superior surface integrity.

7.11. Revolutionizing Wound Healing: Integrating 4D Bioprinting with Adaptive Bioactive Coatings for Dynamic Tissue Regeneration

• Azizeh Rahmani Del Bakhshayesh ¹, Maryam Ghahremani-nasab ¹, Soraya Babaie ² and Mahdiyeh Rahmani Del Bakhshayesh ³

¹ 

Department of Tissue Engineering, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran

² 

Physical Medicine and Rehabilitation Research Center, Aging Research Institute, Tabriz University of Medical Sciences, Tabriz, Iran

³ 

Al-Zahra Technical & Vocational College, Tabriz, Iran

The field of wound healing has seen remarkable progress in recent years, and one of the most exciting innovations is the integration of 4D bioprinting with advanced coatings. 4D bioprinting, an emerging technology that adds the dimension of time to 3D printing, holds transformative potential in creating dynamic, adaptive, and self-regenerating tissue structures. This technology allows the fabrication of biocompatible materials that can respond to environmental stimuli, such as changes in temperature, pH, or mechanical forces, to enhance tissue regeneration.

By incorporating advanced coatings—composed of plant-based bioactive compounds (e.g., polyphenols) or nanomaterials (e.g., silver nanoparticles in hydrogels) and structured as thin, porous layers—into 4D-bioprinted scaffolds, we can create more effective, multifunctional systems for wound care. These coatings interact with the 4D structures by releasing therapeutic agents in response to the scaffolds’ shape or porosity changes over time, facilitating controlled delivery to the wound site. This approach’s novelty lies in the combination of time-responsive 4D-bioprinted structures with bioactive coatings that offer enhanced biocompatibility, antibacterial properties, and promote cellular activities necessary for wound closure, such as migration, proliferation, and extracellular matrix formation. Integrating such coatings with 4D-printed matrices creates dynamic wound-healing environments capable of responding to changes in the wound’s condition over time, optimizing healing and reducing the risk of chronic wounds.

This abstract discusses the potential of 4D bioprinting combined with advanced coatings to revolutionize wound healing by providing customized, adaptive solutions that address both immediate and long-term challenges in tissue regeneration. The proposed technology could significantly improve the efficacy and sustainability of wound care treatments, paving the way for more personalized, precision medicine approaches in the management of complex wounds.

7.12. Surface Preparation of Carbonaceous Films to Increase Wettability and Integration with Nanoparticles for Electrochemical Applications

• Vasilica Țucureanu, Octavian-Gabriel Simionescu, Marius Stoian, Gabriel Craciun and Alina MATEI

• National Institute for Research and Development in Microtechnologies, IMT-Bucharest 126A, Erou Iancu Nicolae Str., 077190 Bucharest, Romania

The two most significant techniques for producing carbonaceous materials with exceptional conductivity for use in electrochemical devices are chemical vapor deposition and mechanical cleavage of graphite. The main advantage of using the CVD technique is represented by the ability to obtain materials that can be used on larger surfaces, with a uniformity superior to cleavage techniques. However, films of carbonaceous materials are hydrophobic, which makes it difficult to integrate nanoparticles. By adding nanoparticles (e.g., metallic, oxide), the electrochemical characteristics of carbonaceous materials can be improved, as a result of the increase in the specific surface of the electrode, catalytic effect, and enhanced electron transfer. In this paper, we present the methodology for modifying the wetting capacity of a graphene film grown on a copper substrate, which we transferred through a chemical process to the SiO₂/Si substrate. To modify the wetting capacity of these materials, both plasma treatment using reactive ion etching equipment and a chemical treatment in acid medium were carried out. For fundamental investigations of the graphene–liquid interface, it is necessary to ensure that the graphene surface is free of any kind of residue. This is important not only to ensure the persistence of favorable properties, but also to ensure an ideal sp² carbon surface to allow suitable chemical interactions with NPs, precursors, and analytical molecules. The research has focused on the use of spectroscopy, SEM, and goniometry as techniques for structural, morphological, wetting capacity, and percolation analyses of carbonaceous materials. Their applicability in the electrochemical field was studied by cyclic voltammetry after the incorporation of nanoparticles.

Acknowledgements: This work was supported by a grant from the Ministry of Research, Innovation and Digitization, CNCS-UEFISCDI, project number PN-IV-P2-2.1-TE-2023-0417, within PNCDI IV, and by the Core Program within the National Research Development and Innovation Plan 2022–2027, project no. 2307.

8. Protective Coatings in Cultural Heritage, Conservation and Preservation

8.1. A Highly Hydrophobic Siloxane-Nanolignin Hybrid Coating for the Protection of Heritage Wood

• Mariana Ramos ¹, Christina Pappa ¹, Panagiotis Manoudis ², Vasiliki Kamperidou ³, Eleni Pavlidou ⁴, Konstantinos Triantafyllidis ¹, Panagiotis Spathis ¹ and Ioannis Karapanagiotis ¹

¹ 

Dept of Chemistry, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece

² 

Lysis Consulting PC, Varnali 25, PC 55534, Pylea

³ 

Dept of Forestry and Natural Environment, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece

⁴ 

Dept of Physics, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece

Wood has been used as a construction material for small objects, furniture, and large-scale buildings since antiquity. The protection of wooden objects and wooden buildings of significant cultural heritage from water-induced decay processes is of great importance. In the present work, hybrid coatings consisting of Sivo 121 and nanolignin were produced and deposited onto chestnut (Castanea sativa) and oak (Quercus frainetto) specimens. Sivo 121 is an aqueous siloxane-based product which is used for wood protection, whereas nanolignin was extracted from beechwood.

The effects of the nanolignin concentration on the wetting properties and surface structures of the hybrid coatings were investigated and an optimal Sivo/nanolignin mass ratio was found for each wood species. This optimal ratio provided enhanced hydrophobicity, as demonstrated by the elevated contact angles (CAs) of water drops. The maximum CA of 145° was measured for coated oak, which is approaching the threshold of superhydrophobicity. However, the rose-petal effect was evident, with water drops remaining pinned even when the coated samples were tilted to a perpendicular position. Notably, the drops rolled off the coatings’ surfaces when the coated wood samples were agitated.

The performance of the hybrid coating with the optimal Sivo/nanolignin mass ratio was evaluated through a series of tests. The coating caused only minor alterations to the natural colour of the two untreated woods (ΔE5) and offered very good protection against water absorption through capillarity. The results of the graveyard durability test highlighted the treatment’s protective efficacy. Furthermore, the coating exhibited excellent chemical and mechanical stability, as confirmed by applying drops of various pHs and conducting the tape peeling test. Finally, the CAs of the coated chestnut and oak were monitored over time after placing the samples outdoors and within an artificially accelerated aging chamber. The results showed that the CAs remained stable over time, confirming the coating’s durability.

8.2. Beautiful Moment, Do Not Pass Away!: How to Extend the Life of Decorative Exterior Coatings

• Małgorzata Zubielewicz ¹, Ewa Langer ¹, Bartosz Kopyciński ^1,2, Grażyna Kamińska-Bach ¹, Leszek Komorowski ³, Damian Wojda ³, Agnieszka Królikowska ³, Matthias Wanner ⁴, Katarzyna Krawczyk ⁴ and Michael Hilt ⁴

¹ 

Łukasiewicz Research Network, Institute for Engineering of Polymer Materials and Dyes, 87-100 Toruń, Poland

² 

Doctoral School, Silesian University of Technology, 44-100 Gliwice, Poland

³ 

Road and Bridge Research Institute, 03-302 Warsaw, Poland

⁴ 

Fraunhofer Institute for Manufacturing Engineering and Automation, 70569 Stuttgart, Germany

Can ensuring the longevity of decorative exterior coatings be as difficult a task as Goethe wrote Faust? The answer is probably not. Fortunately, more and more advanced auxiliaries and binders come to our aid. Moreover, the durability of coatings is significantly influenced by the pigments themselves and their compositions used during formulation. The key assumption of this project is to assess the probability of selecting raw materials and modifying topcoats subjected to aging tests under cyclically changing conditions (temperature, humidity and radiation) in order to maximally extend their usability, by maintaining, among others, colour and gloss. Thus, colour compositions based on two polyurethane binders dedicated to topcoats and pigments in shades of yellow, red and blue were tested. The change in colour, gloss, water contact angles, chemical structure (FTIR) and morphology (SEM) of coatings placed in climatic chambers and exposed to xenon lamps and/or UV were determined. It was shown that the factor with the greatest influence on the change in the performance parameters of coatings is UV radiation. The preservation of the decorative values of coatings also depended on the qualitative composition of the pigments used in each colour group. Changes in humidity and temperature had a slightly smaller effect. In all tests, the surface free energy value and the structure and topography of the coatings did not differ significantly. Based on the obtained results, cycles with a full spectrum of impact on the coatings were selected and ranked, from those causing the least degree of degradation to those showing the most negative impact on the usability of the coatings.

Acknowledgments: The research work was carried out under the project ColourTune CORNET/31/20/2022 entitled “Tuning the colour of topcoats—method for selection of pigments and safeguarding colour stability” funded by the National Centre for Research and Development.

8.3. Composite Edible Coating from Cassava–Arabic Gum Incorporated with Oregano Essential Oil for Preservation Fresh-Cut Mango

• Sebastian Castillo Borjas ¹, Somaris Elena Quintana ¹ and Luis Alberto García Zapateiro ²

¹ 

Complex Fluid Engineering and Food Rheology Research Group (IFCRA). Universidad de Cartagena, 130015. Cartagena de Indias, Colombia.

² 

Unit Operations Department. Faculty of Engineering. Complex Fluid Engineering and Food Rheology Research Group (IFCRA), Universidad de Cartagena, 130015. Cartagena de Indias, Colombia

Mango (Manguifera indica var. Azúcar) is known for its distinctive aroma and flavor that contrast with a short shelf life due to the fruit being highly perishable; thus, it is necessary to find mechanisms that help us extend its shelf life. Currently, the use of biopolymers obtained from plant sources as biodegradable, renewable, and low-cost materials for food packaging, combined with the use of essential oils obtained from plant matrices, is capable of improving mangoes’ antioxidant, antimicrobial, and barrier properties. We evaluated the effect of the application of a composite edible coating from cassava–Arabic gum incorporated with oregano essential oil for the preservation of fresh-cut mango. A composite edible coating was prepared with different concentrations of cassava hydrocolloids (4, 6, and 8% w), Arabic gum (1%), and oregano essential oil (0.25 and 0.5% v/v). The physical properties of the coating solution were analyzed (color, rheology, and microstructure). Then, the composite edible coating was applied by dipping fresh-cut slices of mango into it, and these were stored for 30 days. The water loss, pH, titratable acidity, total solids, and color were evaluated. The experimental data were adjusted to a zero-order kinetic model. The composite edible coating solution presented non-Newtonian shear thinning behavior described by the Carreau–Yasuda model. Coated mango pieces with the highest addition of essential oil demonstrated a decrease of up to 10% in water loss rate and improved preservation of total solids and acidity, leading to a lower difference in color (ΔE) compared to the uncoated sample for up to 30 days. The results suggest that the application of this coating can extend the shelf life of this minimally processed product.

8.4. Development of Self-Cleaning Cementitious Panels with Nano-TiO₂ and Micro-ZnO: Aesthetic and Photocatalytic Impacts of Epoxy Resin Application

• Fabíula Pereira Lessa ¹, Orlando Lima Jr ², Élida Margalho ², Behzad Zahabizadeh ³, Vítor Cunha ³, Eduardo Pereira ³, Aires Camões ⁴, Iran Rocha Segundo ¹ and Joaquim Carneiro ¹

¹ 

Centre of Physics of Minho and Porto Universities (CF-UM-UP), Azurém Campus, University of Minho, 4800-058 Guimarães, Portugal

² 

Advanced Production and Intelligent Systems Associated Laboratory (ARISE), Department of Civil Engineering, Institute for Sustainability and Innovation in Structural Engineering (ISISE), University of Minho, 4800-058 Guimarães, Portugal

³ 

Institute for Sustainability and Innovation in Structural Engineering (ISISE), Institute of Science and Innovation for Bio-Sustainability (IB-S), Department of Civil Engineering, University of Minho, 4800-058 Guimarães, Portugal

⁴ 

Centre for Territory, Environment and Construction (CTAC), Department of Civil Engineering, University of Minho, Azurém, 4800-058 Guimarães, Portugal

Self-cleaning materials are highly relevant for exterior surfaces, such as building facades, and for heritage conservation by preserving the original aesthetic appearance of surfaces with minimal effort and cost. The transparency of these coatings is essential to maintain the visual integrity of existing surfaces. In this context, nanotechnology has emerged as a promising alternative, introducing innovations in coatings and treatments that provide water resistance, self-cleaning properties, and protection against biological attack. Despite their potential, implementing these coatings on cementitious surfaces poses challenges related to long-term stability and performance. Unfixed particles are susceptible to displacement by environmental factors such as rain, wind, and wear, compromising durability and reducing their ability to degrade pollutants and maintain clean facades. This study developed self-cleaning cementitious panels by incorporating TiO₂ nanoparticles and ZnO microparticles at varying concentrations, applied using two deposition methods: spray and dip-coating. Rhodamine B (RhB), an organic dye, was used as a model pollutant to assess self-cleaning performance by monitoring dye degradation during irradiation cycles under simulated sunlight. A spectrophotometric analysis was conducted using the CIELAB color coordinate system to measure chromatic variation and evaluate self-cleaning efficiency. The effect of epoxy resin as a particle immobilizer was also examined, focusing on aesthetic preservation and photocatalytic performance. The results showed that neither the photocatalytic coating nor the resin significantly altered substrate aesthetics, confirming their suitability for facades and heritage preservation. Additionally, photocatalytic coatings improved the surfaces’ self-cleaning properties; however, a slight reduction in photocatalytic efficiency was observed with resin application, likely due to a decrease in the photocatalyst’s active surface area. This highlights the need for further research into alternative resins or surface treatments that optimize particle fixation while maintaining high photocatalytic activity.

8.5. Historic Paint Coatings Applied to Historic Fibrous Plaster

• Dorée Carrier ¹, Philip Fletcher ¹, Adel El-Turki ², Barrie Dams ¹ and Richard J Ball ¹

¹ 

Department of Architecture and Civil Engineering, University of Bath, Bath, BA2 7AY

² 

Interface Analysis Centre, School of Physics, University of Bristol, Bristol, BS8 1TL

Fibrous plaster is a historic material of great prevalence within theaters and auditoriums within the UK, but until recently it has been almost completely unresearched. With the partial collapse of the Apollo Theatre ceiling in 2013, there is growing interest in the safe conservation of fibrous plaster. This study investigates the architectural paint coatings originally applied to fibrous plaster sampled from five London theatres and auditoriums built between 1856 and 1919.

A rigorous analysis of the individual paint layers was conducted using carefully prepared polished cross-sections. The finishes applied were identified using state-of-the-art characterisation techniques, including digital microscopy, SEM imaging, SEM-EDX mapping, Raman spectroscopy, Fourier transform infrared spectroscopy, and water solubility testing. The investigations demonstrated that for 20th-century theatres, lead white oil paint has been shown to constitute their early finish history, whereas venues built before the turn of the century were originally decorated with other materials, including distemper, gold size, and gilding.

This is the first systematic research on architectural finishes originally used on fibrous plaster. The results provide important physical and chemical information relating to the coatings used, informing on the most appropriate conservation approaches. It provides a foundation upon which further investigation into this under-researched material can be based.

8.6. New Fire-Retardant Coatings for Modular Buildings

• Marzena Nowicka-Nowak

• Lukasiewicz Research Network, Institute for Engineering of Polymer Materials and Dyes, Centre for Paints and Plastics in Gliwice, The Paints and Plastics Research Group, Poland

The issue of fire protection for buildings is prevalent primarily in public buildings. The building products used must be flame-resistant or non-combustible, depending on their place of use.

The topic of this presentation concerns innovative coatings for the fire protection of structural elements used in modern modular construction in order to increase their fire safety.

The developed products for painting modular building elements allow for the passive fire protection of structural elements thanks to their ability to delay the ignition of materials covered with them by reducing the spread of flames.

One of the directions we have taken in obtaining fire-retardant paint products was to replace toxic halogen systems with systems based on phosphorus compounds, which allow for their safe use in public buildings.

The focus of this study was on transparent products with short curing times. Both 1K and 2K water-borne and solvent-borne products were selected for testing.

A 2K PUR varnish based on a modified acrylic resin, a 2K epoxy varnish based on a modified epoxy resin, and a water-based varnish based on an acrylic dispersion resin were developed. A 20% addition of active flame-retardant fillers (polyphosphate and polyols derivatives) was introduced to each product.

The obtained varnishes exhibited excellent resistance to open flame exposure. The tests were conducted using a test stand to examine the ignitability of products under the influence of a small flame, in accordance with EN ISO 11925-2:2020.

In conclusion, during the research process, transparent flame-retardant varnishes for wooden substrates, both water-borne and solvent-based, were successfully developed. Careful selection of active fillers as retardants allowed the creation of user-friendly, easy-to-apply, and environmentally friendly products with high fire resistance.

This work was financially supported by the Łukasiewicz Research Network Centre (Poland), Grant number: 1/Ł-IMPiB/CŁ/2021.

8.7. New, Biobased Adhesion Promoters for UV Curing Coatings for Metal Substrates

• Ewa Langer ¹, Małgorzata Zubielewicz ¹, Leszek Komorowski ², Izabela Kunce ², Damian Wojda ², Norbert Pietschmann ³ and Marc Entenmann ³

¹ 

Łukasiewicz Research Network, Institute for Engineering of Polymer Materials and Dyes, 87-100 Toruń, Poland

² 

Road and Bridge Research Institute, 03-302 Warsaw, Poland

³ 

Fraunhofer Institute for Manufacturing Engineering and Automation IPA, 70569 Stuttgart, Germany

UV curing technology is widely used in the furniture, plastic and printing industries. An interesting application of this technique may also be in the future protection of cultural heritage, with a specific focus on metal artifacts. The growing interest in this curing technique is due to its numerous advantages, including low energy consumption, almost zero volatile organic compounds (VOCs) and fast production speed. The use of UV-cured coatings on metal substrates is still very limited, despite many advances made in recent years. The main problems are a lack of adhesion to the substrate or limited corrosion resistance.

The essence of this research is to develop a new method for obtaining and determining the properties of biobased, (meth)acrylated, acidic adhesion promoters. Based on the results of the conducted studies, the conditions for the synthesis process were selected, raw materials were selected for obtaining new biobased adhesion promoters and their properties were tested. The assumed structure of the obtained compounds was confirmed and their basic properties were determined. The use of raw materials from renewable sources to obtain new adhesion promoters was also justified due to issues of environmental protection and sustainable development. Traditional commercial adhesion promoters were also selected for comparative studies.

Acknowledgments: This research was carried out under the project BiBACoM 01/36/CORNET/BIBACOM “Bio-Based UV-Curable Anti-Corrosion Coatings for Metal Substrates” funded by the National Centre for Research and Development (NCBR).

8.8. Preservation of Heritage Through Modern Coatings: Protection of Historical Structures and Cultural Artefacts

• Kachana Kasulu and Anna Viktorovna Solovieva

• Department of Architecture, Restoration and Design, Engineering Academy, Peoples Friendship University Of Russia, Moscow, Russia

Introduction: Environmental factors such as moisture, ultraviolet radiation, atmospheric pollution, and biological organisms pose continuous threats to historical buildings and cultural relics. These risks compromise the structural integrity of these sites while diminishing their aesthetic and historical value. Modern innovative coatings present promising solutions for enhancing long-term preservation, lowering maintenance costs, and safeguarding their authenticity. This study explores innovative protective coatings, including silica-based nanocomposite layers and polyurethane-based healing systems, evaluating their potential as effective means to preserve historic masonry, limestone façades, and metallic artefacts in architectural heritage.

Method: A multiphase experimental approach assessed the effectiveness and compatibility of innovative coatings. Initial laboratory evaluations of accelerated weathering were conducted to quantify the extent of deterioration under controlled conditions, including exposure to ultraviolet radiation, humidity, and temperature variations. The adhesion properties and substrate compatibility were tested using tensile and micro-scratch tests on samples of masonry blocks, limestone samples and aged metal surfaces. Field tests were initiated on individual historical facades across various locations in the city on the same materials to verify real-world performance and gather data regarding durability and ease of application.

Results: Preliminary results indicate that coatings infused with silica-based nanocomposite demonstrate exceptional moisture and contaminant penetration resistance while preserving the substrate’s permeability. Polyurethane-based self-healing systems have been proven to extend service life, reducing overall maintenance needs by autonomously repairing minor damage. Field evaluations illustrated minimal cracking, peeling, or discolouration across substrates, underscoring these coatings’ resilience to varying environmental conditions.

Conclusions: This study confirms the viability of modern coatings as essential components of conservation initiatives. With targeted formulations and successful field application, these coatings offer broad prospects for sustainable and economical preservation of historically and culturally significant structures.

9. The Biomedical Application of Coatings

9.1. Advancing Sanitary Standards: The Role of Copper in Antimicrobial Materials

• Katherine andrea Delgado

• Universidad Bernardo O’Higgins, Santiago 8370993, Chile

Copper, widely recognized for its antimicrobial properties, has proven to be an essential material for reducing environmental contamination and preventing infections. Its antimicrobial action is based on the release of copper ions (Cu⁺ and Cu²⁺), which destroy bacterial membranes and alter proteins and nucleic acids, ultimately resulting in cell death. Compared to other metals such as silver and gold, copper stands out for its high efficacy under various environmental conditions, its sustainability, and its lower cost.

In the hospital setting, copper compounds have been shown to significantly reduce microbial loads on contact surfaces. Notable examples include waiting-room chairs with embedded copper nanoparticles and intravenous pools coated with paints containing copper-structured zeolite particles. In studies conducted in hospital environments, these interventions achieved reductions in viable microorganisms ranging from 50% to 73%, highlighting their effectiveness in preventing healthcare-associated infections, a critical issue in this sector.

Copper-based antimicrobial coatings have also been implemented in confined environments, such as detention cells. In these spaces, where hygiene conditions are limited, surfaces treated with copper-enriched paints achieved bacterial-load reductions ranging from 68% to 87%, including a notable decrease in airborne bacteria. This innovative approach underscores copper’s potential to significantly improve sanitary conditions and reduce the spread of infections in environments with challenging maintenance needs.

Moreover, the integration of copper nanoparticles into polymer matrices represents a disruptive advance in the development of antimicrobial materials. These materials not only retain the mechanical properties of the base polymer but also maximize copper’s biocidal effectiveness, providing versatile and durable solutions. In conclusion, copper continues to position itself as a key component in the design of advanced materials. Its applications in coatings, medical devices, and water-treatment systems stand out for their effectiveness and versatility in improving sanitary conditions in critical sectors.

9.2. Antibacterial Activity of Inorganic and Hybrid Coatings Based on SiO₂, TiO₂ and IrO_x

• Crina Anastasescu ¹, Diana Pelinescu ², Jose Maria Calderon-Moreno ¹, Veronica Bratan ¹, Robertina Ionescu ², Ioan Balint ¹, Ileana Stoica ² and Mihai Anastasescu ¹

¹ 

“Ilie Murgulescu” Institute of Physical Chemistry of the Romanian Academy, 202 Spl. Independentei, 060021 Bucharest, Romania

² 

Faculty of Biology, Intrarea Portocalilor 1-3, Sector 5, 060101 Bucharest, Romania

Titanium-based materials are commonly used for biomedical applications, especially in the dentistry and orthopedic fields, as they are characterized by a wide spectrum of morphological, compositional, and functional parameters. The intensive development of reliable dental implants relies on certain features such as appropriate mechanical resistance, biocompatibility, and the ability to promote Osseo integration. The aim of the work was the identification of the key parameters for obtaining inorganic and hybrid materials coatings appropriate for biomedical application (i.e., dental implants) with intrinsic antibacterial activity. For this purpose, nanostructured TiO₂ modified with Au/Ag metal nanoparticles and lysozyme, coated on titanium foil was synthesized. Scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), photoluminescence (PL), and UV–Vis spectroscopies were used to investigate the morphological, structural and functional properties of the resulting coatings. Several paths were studied as follows. Firstly, the singlet oxygen (¹O₂) generation by inorganic coatings exposed to visible light irradiation was carried out. Then, the antibacterial activity of the TiO₂/Ti, Au–TiO₂/Ti, and Ag–TiO₂/Ti was assessed. The lysozyme bioactivity for Micrococcus lysodeicticus, used as microbial substrate, was evaluated after its adsorption on Lys/TiO₂/Ti, Lys/Au–TiO₂/Ti and Lys/Ag–TiO₂/Ti inorganic surfaces. Finally, the enzymatic activity of the hybrids materials for the hydrolysis reaction of a synthetic organic substrate, 4-Methylumbelliferyl_-D-N,N0,N”-triacetylchitotrioside [4-MU-_- (GlcNAc)3], was emphasized by identifying the presence of a fluorescent reaction product, 7-hydroxy-4-metyl coumarin (4-methylumbelliferone).

9.3. Application of P4VP Polymer Brushes with Embedded Cu Nanoparticles as Antibacterial CSE Platforms

• Anna Cieślik ^1,2, Yana Shymborska ^1,2, Svitlana Tymetska ^1,2, Yurij Stetsyshyn ³, Andrzej Bernasik ⁴, Monika Brzychczy-Włoch ⁵, Kamil Drożdż ⁵, Konrad Szajna ², Franciszek Krok ², Andrzej Budkowski ² and Joanna Raczkowska ²

¹ 

Jagiellonian University, Doctoral School of Exact and Natural Sciences, Łojasiewicza 11, 30-348 Kraków, Poland

² 

Jagiellonian University, Faculty of Physics, Astronomy and Applied Computer Science, Smoluchowski Institute of Physics, Łojasiewicza 11, 30-348 Kraków, Poland

³ 

Lviv Polytechnic National University, St. George’s Square 2, 79013 Lviv, Ukraine

⁴ 

Faculty of Physics and Applied Computer Science, AGH University in Krakow, al. Mickiewicza 30, 30-049 Kraków, Poland

⁵ 

Chair of Microbiology, Department of Molecular Medical Microbiology, Faculty of Medicine, Jagiellonian University Medical College, Czysta 18, 31-121 Kraków, Poland

We developed a cell sheet engineering platform based on poly(4-vinylpyridine) (P4VP) polymer brushes modified with metal nanoparticles (CuNPs) and evaluated their physicochemical properties and biocompatibility. The fabricated coatings exhibited antibiocidal activity and biocompatible characteristics, as well as thermoresponsive behavior, enabling temperature-dependent modulation of their properties.

The chemical composition and surface morphology of the coatings were characterized using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). Additionally, the release of CuNPs from the P4VP coatings was quantified through XPS.

The thermoresponsive nature of the coatings was verified by measuring water contact angles and collecting UV-Vis absorbance spectra as a function of temperature.

The antimicrobial properties of the CuNP-modified P4VP brushes were assessed through microbiological tests targeting contact- and release-based killing mechanisms, both of which demonstrated significant antibacterial efficacy.

To assess brushes’ biocompatibility, protein adsorption onto the polymer brushes was evaluated using immunofluorescence and immunochemistry assays. Furthermore, retinal pigment epithelium cells (ARPE-19 line) were cultured on the fabricated coatings, and cell viability was analyzed using the MTT assay. The results indicated sustained cell viability over time, suggesting biocompatibility of the coatings.

The thermoresponsive behavior of the P4VP brushes facilitated the spontaneous detachment of ARPE-19 cell sheets upon cooling. Post-detachment observations confirmed maintained viability of the released cells.

In conclusion, our study demonstrates the feasibility of creating biocompatible, thermoresponsive polymer coatings capable of spontaneous cell sheet detachment. These antibacterial, thermoresponsive coatings hold promise for applications in cell sheet engineering platforms for therapeutic purposes.

The study was funded by the “Research support module” as part of the “Excellence Initiative—Research University” program at the Jagiellonian University in Kraków (RSM/80/CA).

9.4. Assessment of Hydroxyapatite Coatings Doped with Silver and Strontium Through Galvanostatic Pulse Technique

• Elena Ungureanu ¹, Diana Maria Vranceanu ¹, Alina Vladescu (Dragomir) ², Anca Constantina Parau ², Anisoara Cimpean ³ and Cosmin Mihai Cotrut ¹

¹ 

National University of Science and Technology POLITEHNICA of Bucharest, 313 Independeței Street, 060042 Bucharest, Romania

² 

National Institute of Research and Development for Optoelectronics INOE 2000, 409 Atomistilor St., 077125 Magurele, Romania

³ 

Department of Biochemistry and Molecular Biology, University of Bucharest, 91-95 Independentei Street, 050095 Bucharest, Romania

Introduction: Hydroxyapatite coatings are a rapidly expanding field that focuses on the addition of various elements to obtain tunable properties. The electrochemical techniques enable the assessment of coatings based on hydroxyapatite doped with various elements that promote cell growth and osteogenic differentiation while exhibiting antibacterial properties.

Methods: The aim of this study was to obtain hydroxyapatite-based coatings doped with Sr and Ag through the galvanostatic pulse technique. The electrolytes were obtained by subsequently dissolving in ultra-pure water of the following chemical reagents, Ca(NO₃)₂·4H₂O, NH₄H₂PO₄, Sr(NO₃)_2, and AgNO₃ in different concentration with respect to a Ca/P ratio of 1.67. The electrolyte’s pH was adjusted to 5. The coatings were characterized in terms of morphology, elemental and phasic composition, wettability, and roughness. Subsequently, the hydroxyapatite-based coatings were tested in vitro by evaluating their electrochemical behavior and their cellular response to preosteoblast cell cultures.

Results and Discussion: The galvanostatic pulse technique has allowed the development of uniform and compact hydroxyapatite-based coatings, undoped and doped with Sr and/or Ag, that registered a Ca/P ratio closer to 1.67. The XRD analysis highlighted hydroxyapatite as the main phase in all coatings. The contact angle analysis with simulated body fluid (SBF) showed that all coatings have a strong hydrophilic character, registering contact angles within 8–10°. The average roughness (Ra) registered values between 300 and 700 nm and a tendency toward a symmetrical topography. The best electrochemical behavior was registered by undoped HAp-based coatings. The studies regarding the response of the preosteoblasts indicated that these surfaces favor the adhesion and proliferation capacity of preosteoblasts, while the addition of Sr exerted beneficial effects on preosteoblast response, irrespective of the presence or absence of Ag.

Conclusions: Thus, the undoped and doped hydroxyapatite coatings with strontium and/or silver obtained at pH 5 denoted enhanced and tunable properties for medical applications.

9.5. Carbon-Based Nanocoatings with Advanced Antimicrobial Performance

• Mohammed Suleman Beg, Daniel Redman, Antonios Kelarakis and Ashraf Khallel Ibrahim Al-baghdadi

• UCLan Research Centre for Smart Materials, School of Pharmacy and Biomedical Sciences, University of Central Lancashire, Preston PR12HE, UK

Introduction: The development of advanced coatings can play a pivotal role in combating antimicrobial resistance infections and the severe threats they pose to modern societies. To this end, the presentation will focus on a new family of layer-by-layer antimicrobial coatings that capitalise on the electrostatic attractions between negatively charged Nafion and positively charged graphene quantum dots (GQDs) and graphene oxide (GO).

Methods: Quartz crystal microbalance is used to monitor the build-up of nanocoatings in real time. Zeta potential measurements, Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), and contact angle measurements were used to characterise the materials that were also assessed with respect to their antimicrobial performance against E. coli and S. aureus.

Results: Nafion demonstrates superior chemical, thermal, and mechanical stability stemming from its Teflon-like backbone coupled with its long-range bacteria exclusion zone (EZ) associated with the presence of charged pendant groups. The chemical modes of the bactericide activity of GQDs and GO are related to the induction of membrane stress and the release of reactive oxygen species (ROS), as well as binding with DNA to restrain cell proliferation and arrest gene expression. The Nafion/GO and Nafion/GQD nanocoatings can effectively inhibit the growth of representative Gram-positive and Gram-negative bacteria by more than 99%, and this performance is not compromised following extensive thermal annealing.

Conclusion: In addition to their excellent antimicrobial performance, the nanocoatings combine a number of attractive characteristics including structural and chemical stability, non-toxic characteristics, superior UV barrier properties along with their waterborne, transparent, and colourless nature. The nanocoatings are able to withstand dry heat sterilisation and are ideal for surgical blades, surfaces used for food processing and storage, and packaging for cosmetics, drugs, and biological materials.

9.6. Copper-Doped Hydroxyapatite-Based Coatings for Medical Applications

• Georgiana Cioranu ¹, Elena Ungureanu ¹, Anca Constantina Parau ², Alina Vladescu (Dragomir) ², Diana Maria Vranceanu ³ and Cosmin Mihai Cotrut ³

¹ 

National University of Science and Technology Politehnica Bucharest, 313 Splaiul Independentei, 060042 Bucharest, Romania

² 

National Institute of Research and Development for Optoelectronics—INOE 2000, 77125 Magurele, Romania

³ 

National University of Science and Technology POLITEHNICA Bucharest, 313 Independentei Street, 060042 Bucharest, Romania

The success of an implant depends on its osseointegration, while its long-term survival is determined by its resistance to bacterial infections. Titanium, commonly used for its mechanical properties and corrosion resistance, has limitations regarding its osteointegration and antibacterial efficiency [1,2]. The present work’s aim is to functionalize the Ti surface with hydroxyapatite doped with copper, known for its antibacterial properties and ability to stimulate bone regeneration.

The coatings were obtained by electrochemical deposition of HAp on Ti and subsequent doping by an ion exchange method with a copper solution. The HAp deposition was carried out in pulsed galvanostatic mode at 75 °C from two types of electrolytes: Ca nitrate and Ca chlorate salts. The coatings were characterized in terms of morphology, chemical and phase composition, surface roughness, and thickness. SEM images showed that the HAp coating morphology consists of ribbon-like crystals, irrespective of the electrolyte or the presence of Cu. The EDS analysis highlighted the presence of Cu ions and a (Ca + Cu)/P ratio between 1.54 and 1.59. In terms of coating thickness, it was noted that when chloride salts were used, the thickness was smaller than when nitrates were used. Cu addition to HAp resulted in a slight decrease in thickness, regardless of the electrolyte. XRD analysis confirmed the presence of the HAp phase and HAp coatings successfully doped with Cu.

In conclusion, it can be stated that hydroxyapatite-based coatings obtained through electrochemical techniques can be successfully doped with copper by using the ion exchange method.

References

[1] F. A. Al-Mulhim, M. A. Baragbah, M. Sadat-Ali, A. S. Alomran, M. Q. Azam, Int Surg 2014, 99, 264.

[2] D. M. Vranceanu, E. Ungureanu, I. C. Ionescu, A. C. Parau, V. Pruna, I. Titorencu, M. Badea, C.-Ștefania Gălbău, M. Idomir, M. Dinu, A. V. (Dragomir), C. M. Cotrut, Biomimetics 2024, 9, 244.

9.7. Development of Biofunctional Textiles: Microencapsulation of Lemongrass Oil and Salicylic Acid for Dermocosmetic Applications

• Fabricio Bezerra ¹, Murilo Pereira Moises ², Manuel Jose Lis ³ and Juan P Hinestroza ⁴

¹ 

Federal University of Technology Paraná (UTFPR), Apucarana 86812-460, PR, Brazil

² 

Chemistry (COLIQ), Federal University of Technology—Paraná (UTFPR), Apucarana 86812-460, PR, Brazil

³ 

Laboratory of Surfactants and Detergency, Terrassa School of Engineering, 08222 Barcelona, Spain

⁴ 

Fiber Science Program, Department of Human Centered Design, College of Human Ecology, Cornell University, Ithaca, New York 14853, United States

Introduction: Textile finishes have long been used to add functional properties to fabrics. These functionalities can be applied to textile substrates in various ways. However, one of the most common approaches is through the use of microcapsules, which provide protection to the encapsulated active compounds against potential adversities. Microcapsules are widely employed in various fields, including textiles, pharmaceuticals, and cosmetics. In the textile sector, they are used in the development of biofunctional textiles, which serve as vehicles for transporting encapsulated actives, allowing them to come into contact with the skin and perform cosmetic or medicinal functions. This study introduces a novel textile finish based on microcapsules containing lemongrass essential oil and salicylic acid, produced via in situ polymerization—a unique combination not previously reported in the literature. Methods: The microcapsules were characterized using scanning electron microscopy (SEM) for morphology, dynamic light scattering (DLS) for particle size, and Fourier-transform infrared spectroscopy (FTIR) for chemical composition. Loading efficiency, thermal stability (via thermogravimetric analysis, TGA), and free formaldehyde detection were assessed to ensure safety compliance. The microcapsules were applied to 100% cotton fabric using the pad-dry technique, with functionalization confirmed by SEM and TGA. Results: SEM revealed an irregular morphology, while DLS indicated an average particle diameter of 1.95 µm. FTIR confirmed the chemical composition, and loading analysis showed 67.90 ± 1.41% lemongrass oil in the core. TGA and formaldehyde detection confirmed compliance with Brazilian Health Regulatory Agency (ANVISA) safety standards. Successful application to cotton fabric was validated by SEM and TGA, demonstrating effective functionalization. Conclusion: The microcapsules produced via in situ polymerization show significant potential for dermocosmetic applications and textile functionalization. This study underscores the innovative potential of combining lemongrass oil and salicylic acid in microcapsules, paving the way for new cosmetotextile products and further exploration in this field.

9.8. Development of Ceramic-Like Surfaces on Mg-Based Screw Implants for Orthopedic Application via PEO (Plasma Electrolytic Oxidation) Process

• Anna Buling and Pouria Ghiasi

• ELB Eloxalwerk Ludwigsburg GmbH, 71642 Ludwigsburg, Germany

Magnesium (Mg) and its alloys have recently arisen as promising biomaterials fulfilling the requirement of functional bone tissue support and aid to its regeneration. Permanent non-biodegradable implants such as titanium (Ti), cobalt–chrome, and stainless steel can cause inflammation, toxicity (infection), and sometimes improper bone healing. Thus, an additional or alternative surgical procedure is required to remove these implants from the body after the healing process. Mg shows bioresorbable, biodegradable, and biocompatible properties. Furthermore, it degrades without causing any toxicity, and henceforth, additional surgery can be avoided. Apart from its biocompatible properties, it also demonstrates good mechanical properties like low density and elastic modulus in the range compatible with bone structures [3].

Despite all the virtues of Mg, its swift corrosion rate and degradation in an in vivo atmosphere may cause early fracture before complete bone healing, greatly hindering its application as an implant material. Furthermore, gas evaluation due to fast degradation may cause encapsulating processes. To overcome such corrosion behavior, a refinement on Mg-based screw implants by a PEO (plasma electrolytic oxidation) process is developed, ensuring a dimensional stability of 2 months in a corrosive environment. The current work was accomplished under various PEO regimes to obtain the desired thickness and other essential properties best suited for Mg-based screw implants.

The microstructure, chemical composition, and surface properties of the PEO were investigated and compared via scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). SEM/EDS analysis illustrated the morphology of PEO, the elemental/phase distribution, and the formed barrier layer at the substrate/oxide layer interface for different process parameters, drastically altering the corrosion behavior and mechanical properties. The corrosion resistance of various PEO surfaces was studied by using electrochemical analysis techniques such as electrochemical impedance spectroscopy in 0.9-wt% NaCl solution at 36 °C. The results showed significant improvement in the corrosion behavior of PEO samples when compared with uncoated Mg surfaces.

9.9. Eco-Friendly Alginate Films Embedding Zinc Oxide Nanostructures: Assessing the Oral Bioaccessibility of Zinc in a Dynamic Mode Using a Fully Automatic Flow-Through System

• Antonica Valeria Montefusco ^1,2, Miguel Oliver Rodríguez ³, Maria Magdalena Pons Guasp ³, Margherita Izzi ¹, Nicola Cioffi ¹, Rosaria Anna Picca ¹ and Manuel Miró Lladó ³

¹ 

Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, Via E. Orabona 4, 70126 Bari, Italy

² 

Dipartimento di Ingegneria Elettrica e dell’Informazione, Politecnico di Bari, Via E. Orabona 4, 70126 Bari, Italy

³ 

FI-TRACE Group, Department of Chemistry, University of the Balearic Islands, Carretera de Valldemossa km 7,5, E-07122 Palma de Mallorca, Spain

Novel food packaging films based on biopolymers combined with antimicrobial inorganic nanostructures (NSs) have been developed to replace traditional plastics. However, little is known about their possible toxicity and oral bioaccessibility if accidentally ingested.

In this contribution, we studied the zinc bioaccessibility of ZnO NSs-modified alginate films, setting up a dedicated flow system utilizing sequential injection analysis (SIA) for its automatic evaluation over time through a dynamic approach mimicking human digestion by gastric fluid (GF).

Crosslinked ZnO NSs/alginate films were thus fabricated. NSs were prepared using an electrochemical–thermal method and added directly to the alginate solution. Films were formed by dry casting and crosslinked with Ca²⁺ solution. ICP-OES characterization was carried out to verify the real zinc content in the films before testing, as compared to the nominal mass content. An SIA system was designed to profile the temporal release of zinc ions from nanocomposites. The analysis started by pumping synthetic GF onto film pieces in a flow-through container under fluidized-bed conditions, and then, at fixed times, part of this fluid was automatically retrieved and mixed on-line with borate buffer and Zincon for in-line spectrophotometric detection. A sudden release occurred within the first 3 min of extraction followed by a more gradual release.

The proposed approach based on a dynamic extraction method using an automatic SIA system is deemed an interesting solution for the high-throughput assessment of metal ion bioaccessibility in antimicrobial-containing packages without using in vivo or in vitro cell tests. Moreover, it could be applied to other targets (e.g., plasticizers, antioxidant compounds) just by modifying the analytical method.

AVM acknowledges funding from the European Union—NEXTGENERATIONEU—NRRP MISSION 4, COMPONENT 1. MO and MM acknowledge financial support from the Spanish Ministry of Science and Innovation (MCIN), and the Spanish State Research Agency (AEI/10.13039/501100011033) through the project PID2020-117686RB-C33 (MCIN/AEI).

9.10. Effect of Hybrid Hierarchical PEO/PLA Coatings on Corrosion Performance of Additively Manufactured Ti6Al4V in Simulated Body Fluid

• Shaghayegh Javadi, Raul Arrabal, Maria Isabel Barrena and Endzhe Matykina

• Ingeniería Química y de Materiales, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Madrid 28040, Spain

Plasma electrolytic oxidation (PEO) coatings and biodegradable polymers such as polylactic acid (PLA) present interest as drug-eluting systems for osseointegrated biomedical implants. Given the biodegradable nature of PLA, the coating system may induce crevices at one or more interfaces during degradation. Crevices are known to severely affect the corrosion performance of additively manufactured (AM) Ti alloys. Therefore, understanding the interactions between the PEO/PLA system and titanium alloys is crucial for enhancing the longevity of implants. This study investigates the corrosion of mill-annealed and AM Ti-6Al-4V alloys functionalized with porous hybrid hierarchical coatings comprising a ceramic layer produced by plasma electrolytic oxidation and one or more polylactic acid layers.

PEO coatings were formed using an AC power supply on wrought and DMSL-produced Ti6Al4V. PLA was applied on PEO-coated samples by dip-coating using the “breath figures” technique. Optical profilometry, scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive spectroscopy (EDS) were utilized to assess the topography, morphology, phase composition, and elemental distribution in the coated alloys. Corrosion performance was evaluated through DC and AC electrochemical tests, including potentiodynamic polarization and electrochemical impedance spectroscopy (EIS), conducted in a simulated body-fluid at 37 °C to mimic real-world conditions, including the presence of a controlled-size crevice.

The results revealed ~3.5–5.5 µm thick anatase- and rutile-based coatings enriched in several bioactive elements, at.%: 7.6% Ca, 5.76% P, 0.23% Zn, 1.5% Mg, 3.52%Si. The ~2 µm thick PLA layer featured a 1–6 µm pore size and ~75,000 pores mm⁻². The PEO coating helped in avoiding the localized corrosion of AM Ti6Al4V. The post-corrosion characterization also elucidates the role of biodegradable sealing layers in crevice formation.

In conclusion, the PEO/PLA system is a viable coating material for enhancing the durability of AM Ti6Al4V. This research provides a foundation for future studies aimed at exploring alternative biodegradable materials as drug-eluting media.

9.11. Experimental Design-Based Optimization of Bioactive Coatings for Sustainable Antimicrobial Applications

• Margherita Izzi ^1,2, Alessandro Faranda ¹, Claudio Stucchi ¹, Antonica Valeria Montefusco ^1,2,3, Barbara Giussani ⁴, Rosaria Anna Picca ^1,2 and Nicola Cioffi ^1,2

¹ 

Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, Via E. Orabona 4, 70126 Bari, Italy

² 

CSGI (Center for Colloid and Surface Science), Unità di Bari, Via E. Orabona 4, 70126 Bari, Italy

³ 

Dipartimento di Ingegneria Elettrica e dell’Informazione, Politecnico di Bari, Via E. Orabona 4, Bari, Italy

⁴ 

Dipartimento di Scienza e Alta Tecnologia, Università degli Studi dell’Insubria, Via Valleggio 11, 22100 Como, Italy

The uncontrolled spread of infectious diseases has driven the development of innovative materials designed to control microbial transmission and combat harmful pathogens. In this context, inorganic materials have emerged as promising candidates for bioactive coatings, offering intrinsic antimicrobial properties, biocompatibility, and potential eco-friendly applications. However, in accordance with the atom economy and safety criteria outlined by the Green Chemistry Principles, it is essential to ensure the use of the minimal effective dose of antimicrobial agents. This approach minimizes potential toxic effects while optimizing antimicrobial action. Chemometric tools have proven invaluable in designing and refining experimental protocols to achieve these objectives.

This communication proposes innovative strategies for synthesizing and characterizing bioactive coatings based on nanostructured and hybrid inorganic materials. Specifically, two cases of study are presented, focusing on zinc oxide and silver phosphate nanostructures. These materials were synthesized using green electrochemical and precipitation methods and subsequently embedded in polymeric matrices, such as polyvinyl alcohol (PVA), to develop bioactive films via self-standing procedures. Special emphasis was placed on optimizing experimental parameters through chemometric tools.

The chemometric approach enabled the development of materials with reproducible and tuneable properties, ensuring a synthetic yield exceeding 85%. Comprehensive analytical characterization—including electron microscopy, spectroscopy techniques, and solubility studies—was performed to establish correlations between synthesis conditions, material properties, and their potential applications. The antimicrobial structures have nano- and microscale dimensions, and the composite films ensure a controlled release of the metal ions over time.

The findings highlight the potential of these bioactive coatings for industrial-scale production, addressing critical challenges in antimicrobial resistance and promoting sustainable material development.

M.I. acknowledges the financial support from the ERC SEEDS UNIBA programme, project H93C23000660001, “REAL—More for less: REthinking AntimicrobiaL materials”. A.V.M. acknowledges funding by the European Union –NEXTGENERATIONEU—NRRP MISSION 4, COMPONENT 1.

9.12. Gelatin–Chitosan Hydrogels with Encapsulated Essential Oils: A Novel Antibacterial Coating for Biomedical Applications

• Alexandru Vasile Rusu ¹, Paul Andor ², Monica Trif ³, Alexandra Trif ⁴, Mihai Domnutiu Suciu ⁵ and Gulden Goksen ⁶

¹ 

CENCIRA Agrofood Research and Innovation Centre, Ion Meșter 6, 400650 Cluj-Napoca, Romania

² 

University of Agricultural Sciences and Veterinary Medicine, 400372 Cluj-Napoca, Romania

³ 

Centre for Innovative Process Engineering (CENTIV) GmbH, 28816 Stuhr, Germany

⁴ 

University of Oradea, 410087 Oradea, Romania

⁵ 

Department of Urology, Clinical Institute of Urology and Kidney Transplant, “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania

⁶ 

Department of Food Technology, Vocational School of Technical Sciences at Mersin Tarsus Organized Industrial Zone, Tarsus University, Mersin 33100, Türkiye

Gelatin-based hydrogels incorporating chitosan-encapsulated essential oil microcapsules have emerged as promising antimicrobial materials for biomedical applications. These hydrogels offer a biocompatible and biodegradable platform with enhanced antibacterial efficacy against Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) bacteria. Chitosan provides inherent antimicrobial properties while acting as an effective carrier for essential oils, ensuring controlled release and prolonged antibacterial activity. The hydrogel matrix typically consists of 5–15% (w/v) gelatin and 1–5% (w/v) chitosan, and crosslinking agents at 0.1–1% (w/v) are used to enhance mechanical stability. Chitosan acts as both a structural component and an antimicrobial agent while also serving as an effective carrier for essential oils. Essential oils such as peppermint (1–2%), clove (0.5–2%), cinnamon (1–3%), and ginger (1–1.5%) were encapsulated (essential oil-to-chitosan ratio: 1:3 to 1:5), and an encapsulation efficiency of 70–90% was achieved. The antibacterial mechanism is attributed to chitosan’s electrostatic interactions with bacterial cell membranes and the sustained controlled release of bioactive compounds. The hydrogels also offer moisture retention, mechanical stability, and barrier protection, making them highly suitable for wound dressings, tissue engineering, and infection prevention. Recent studies have shown that gelatin–chitosan hydrogels incorporating essential oils not only enhance antibacterial efficacy but also support cellular proliferation and tissue regeneration. Therefore, due to their multifaceted advantages, the hydrogels represent a significant advancement in biomedical coatings. Further research is needed to optimize formulation parameters and evaluate long-term biocompatibility for clinical applications.

9.13. Graft Copolymer of Cellulose and Saturated Polyester as a Compatibilizer in an Epoxy Composite

• Irina Vikhareva

• South Ural State University, Lenin Prospect 76, 454080 Chelyabinsk, Russia

Cellulose is a biopolymer of great interest for biomedical applications, providing increased rigidity and strength in polymer matrices, biocompatibility, and non–toxicity. However, the hydrophilic structure of cellulose leads to the aggregation of its particles in hydrophobic matrices. The presence of OH groups in the cellulose structure opens up wide possibilities for its chemical modification in order to improve compatibility. Most cellulose modification processes involve expensive toxic solvents, which helps to reduce the environmental friendliness of the process.

Graft copolymerization of cellulose and polyester resin based on sebacic acid was carried out by the method of mechanochemical activation, and a compatibilizer was obtained. The IR spectroscopy method shows the grafting of polyester to cellulose and selects the optimal amount of polyester for the complete interaction of the hydroxyl groups of cellulose. Epoxysmole was chosen as the matrix. Composites with different contents of graft copolymers of cellulose and polyester were obtained. The surface structure of the composites was analyzed using scanning electron microscopy. The uniformity of the filler distribution in the matrix and the uniformity of the structure were shown regardless of the amount of filler. The main physical, mechanical, and operational characteristics of the composites weredetermined. In comparison with the unfilled composite, the samples demonstrated an 8% increase in the strength of composites at a content of 0.5% and a 20% increase at a content of 1%; a significant increase was also observed in the modulus of elasticity (200% and 270%, respectively), and the deformation index increased with a low filler content, followed by a slight decrease. Thermal analysis of the composites did not show a noticeable decrease in the thermal stability of the samples.

Bisompatible and biodegradable graft copolymers of cellulose and polyester resin were obtained with the possibility of use in various polymer matrices for medical purposes.

9.14. Innovations in Biomedical Coatings: Nanostructured and Biodegradable Solutions

• Medha Gayatri Bhatiprollu

• Department of Pharmacy Sarojini Naidu Vanita Pharmacy Maha Vidyalaya, Tarnaka, Telangana, India-500017

The use of nanostructured and biodegradable coatings is of great importance in the field of biomedical engineering with regard to implantable medical devices, drug delivery systems and even controlled release mechanisms for medicine. These types of coatings utilize the advantages of nanotechnology to improve the surface properties of diverse materials, which include structures that are more compatible with biological tissues, enhanced mechanical strength, and functionalization. Coatings that include nanoparticles or nanofibers, for example, are referred to as nanostructured coatings. These coatings have enhanced antimicrobial properties, greater cell adhesion, and controlled release of drugs. Such characteristics make them suitable for the treatment of wounds, surgical implants, and tissue engineering scaffolds.

Some biodegradable coatings are fabricated from polylactic acid (PLA), polycaprolactone (PCL), and even chitosan, which reduce environmental impacts and do not require surgical extraction after application. They are especially useful in drug-eluting systems, where the degradation of the coating material after the process is used to ensure that controlled and sustained release of the drug is achieved, which dramatically increases the desirable therapeutic action and significantly decreases side effects.

It is also noteworthy that the merging of nanostructured features and biodegradable materials produces hybrid coatings suitable for stents, orthopedic implants, and biosensors, which employ composite materials with composite properties. These coatings also aid in early diagnosis and treatment through personalized medicine. As materials science and nanotechnology progress, the world’s focus is on integrating the use of nanostructured and biodegradable coatings, which will surely help modern biomedical applications with their great innovations, safety, and improvements in patient treatment.

9.15. Innovations in Needle Coatings: Reducing Tissue Trauma and Improving Accuracy in Medical Procedures

• Soraya Babaie ¹, Azizeh Farshbaf-Khalili ¹, Azizeh Rahmani Del Bakhshayesh ² and Bina Eftekharsadat ³

¹ 

Physical Medicine and Rehabilitation Research Center, Aging Research Institute, Tabriz University of Medical Sciences, Tabriz, Iran

² 

Department of Tissue Engineering, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran

³ 

Physical Medicine and Rehabilitation Research Center, Aging Research Institute, Department of Physical Medicine and Rehabilitation, Tabriz University of Medical Sciences, Tabriz, Iran

Background: Needle penetration is crucial in various fields, especially in medical applications. Recent studies indicate that, in addition to size and point type, needle coatings significantly impact penetration forces. During needle insertion, the needle body directly contacts biological soft tissue, often leading to tissue adhesion and varying degrees of tissue damage. Therefore, coating needles can substantially reduce tissue trauma during insertion.

Methods: Optimizing the needle surface, particularly through coatings, can effectively address these issues. Various coatings, including biocompatible hydrophilic, metallic glass, silicone, and composite materials, have been studied. These coatings can reduce friction during insertion, minimize tissue adhesion, and decrease insertion and extraction forces.

Results: Coating surgical needles with a composite material (Polytetrafluoroethylene, Polydopamine, and Activated Carbon) reduced insertion and extraction forces, showing promising results with a reduction in insertion force by up to 49% and tissue damage by 39% in bovine kidney experiments. This coating also minimized tissue damage during percutaneous procedures. A biocompatible hydrophilic coating on a needle reduced tissue damage and adhesion during a puncture biopsy procedure. A silicone coating enhanced the durability and sharpness of surgical needles when passing through certain tissues, and a metallic glass coating on tattoo needles reduced skin trauma and improved tattoo quality.

Conclusions: These innovations in needle coatings show promise for minimizing tissue damage, improving precision, and promoting faster healing.

9.16. Multifunctional Synthesized Flavonoid Complexes for Novel Anticancer Drug Coating Applications

• Ana Kandić ¹, Malte Bethke ², Stefan Nikolić ¹, Monica Trif ² and Ljiljana Mihajlović ¹

¹ 

Innovative Centre Faculty of Chemistry Belgrade Ltd., Belgrade, Serbia

² 

Centre for Innovative Process Engineering (CENTIV) GmbH, 28816 Stuhr, Germany

Flavonoid-based compounds have attracted significant attention in cancer research due to their potent anticancer properties, including their antioxidant, anti-inflammatory, and anti-proliferative effects. However, their application is often hindered by challenges such as their poor solubility, low bioavailability, and instability under physiological conditions. The MET-EFFECT project (EU-funded under HORIZON-MSCA-SE-2021) aims to address these limitations and focuses on the development of novel multifunctional flavonoid complexes based on rhenium and iridium, with the aim of these serving as metallodrugs and homogenous catalysts. Additionally, the project will propose personalized drug design delivery systems using new green methodologies for valorization in order to improve the delivery and bioavailability of active constituents with potential anticancer properties. These coatings will be tailored to provide controlled release mechanisms that enhance the bioavailability of the active compounds and ensure their targeted delivery to cancerous tissues. The ability to immobilize these biofunctional molecules within films and coatings holds significant potential in advancing the field of drug delivery, enhancing therapeutic efficacy, and contributing to the development of next-generation anticancer therapies. Therefore, the MET-EFFECT project will offer a cutting-edge approach to overcoming the current barriers in cancer treatment by harnessing the power of novel flavonoid-based complexes incorporated into functionalized coatings, presenting a promising solution for localized drug delivery and improved therapeutic outcomes.

9.17. Novel Composite Films Starting from Black Soldier Fly Protein Extract

• Francesco Iannielli ¹, Margherita Izzi Izzi ², Carmen Scieuzo ¹, Andrea Brattelli ², Rosanna Salvia ¹, Maria Chiara Sportelli ², Luigi Gentile ², Rosaria Anna Picca ², Nicola Cioffi ² and Patrizia Falabella ¹

¹ 

University of Basilicata, Via dell’Ateneo Lucano 10, 85100 Potenza, Italy

² 

University of Bari Aldo Moro, Via E. Orabona 4, 70126 Bari, Italy

In the last decades, green biomaterials have been explored as alternatives to conventional petroleum-based polymers for applications in the health and food sectors [1]. Biomass-related proteins present intriguing biopolymers to be used as sustainable, biocompatible, and biodegradable building blocks to design innovative coatings and films [2]. Insect-derived proteins are a promising and novel building block for functional coatings. Hermetia illucens, commonly known as Black Soldier Fly (BSF), has the ability to convert organic waste into a valuable larval biomass. The latter is rich in proteins of high biological value and has gained attention mainly as animal feed [3]. In this contribution, BSF proteins are proposed as raw material for bioplastics due to their film-forming properties. The preparation of composite films based on BSF protein extract, along with their spectroscopic and mechanical characterization, is presented. Protein extraction was performed on defatted BSF larvae powder, using a modified method basedon Caligiani et al. [4]. A critical step for suitable dry-casted film formation was protein solubilization. The proper combination of sodium dodecyl sulphate (SDS) as surfactant and glycerol as plasticizer was evaluated based on tensile strength and strain tests. Infrared characterization demonstrated good film homogeneity. Preliminary experiments on the incorporation of antimicrobial zinc-based materials [5] for coating preparation were also carried out. In conclusion, our results demonstrate the potential of BSF proteins as a novel source for bio-based film preparations, opening the door to their use for diverse technological applications.

References

[1]. Q. Lin et al., ACS Biomaterials Science & Engineering 10 (2024) 6751–6765

[2]. S. Gopalakrishnan et al., Adv. Sustainable Syst. 5 (2021) 2000167.

[3]. K. B. Barragan-Fonseca et al., Journal of Insects as Food and Feed 3 (2017) 105–120.

[4]. A. Caligiani et al., Food research international 105 (2018) 812–820.

[5]. M.C. Sportelli et al., Nanomaterials 10(2020) 473.

9.18. Plasma-Deposited Polymer Coatings for Improved Biocompatibility of Titanium Implants

• Aleksei Demakov, Elizaveta Sergeevna Permyakova and Dmitry Vladimirovich Shtansky

• National University of Science and Technology MISIS, Moscow, Russia

The surface modification of titanium implants is essential for improving osteointegration and cellular contact, since untreated surfaces may result in fibrous tissue growth and an elevated risk of infections, hence diminishing implant efficacy. Plasma chemical treatment is an environmentally sustainable technique for applying polymer coatings to various surfaces, enabling meticulous regulation of surface characteristics. The integration of functional groups, including carboxyl and amino groups, enhances hydrophilicity and tissue contact, rendering these coatings particularly advantageous for biomedical applications. This study examines the impact of several plasma chemical treatments on the surface characteristics of titanium implants.

Plasma modification was conducted with the ZP-COVANCE-RFPE-3MP plasma system (13.56 MHz). Three therapy modalities were evaluated, commencing with plasma chemical activation in an Ar/O₂ environment (200 W, 10 min). In the initial mode, activated samples were submerged in a 25% collagen solution for one hour. The second approach entailed the deposition of amino groups by cyclopropylamine (C₃H₅NH₂) in a CPA/Ar plasma at 50 W. The third mode introduced carboxyl groups via a gas combination of Ar, CO₂, and C₂H₄ at 150 W. Plasma-deposited polymer films were examined utilizing SEM, EDX, XPS, FTIR, and WCA techniques. The adhesion and proliferation of mesenchymal stem cells were quantitatively assessed through fluorescence microscopy.

Plasma deposition yielded homogenous, well-adhered layers devoid of pinholes or fissures, as evidenced by SEM micrographs. Wettability assessments demonstrated a substantial enhancement, with an approximately 100° decrease in the contact angle in the optimal mode alongside notable stability. The coatings facilitated improved adherence and proliferation of mesenchymal stem cells.

Plasma treatment of titanium implants enhanced surface characteristics and biocompatibility. These findings underscore the promise of plasma-deposited polymer coatings for biomedical applications.

This research was funded by the Russian Science Foundation (№24-79-10121).

9.19. Surface Engineering of Ti6Al4V Alloys by Bioactive Coatings

• Mayara Carla Uvida ¹, Silvia Rodriguez Fernandez ², Maria Elena Lombardo ², Pascale Chevallier ², Diego Mantovani ² and Peter Hammer ¹

¹ 

São Paulo State University (UNESP), Institute of Chemistry, Araraquara, SP, Brazil

² 

Laboratory for Biomaterials and Bioengineering, CRC-I, Dept of Min_Met-Materials Eng., & University Hospital Centre, Regenerative Medicine, Laval University, Quebec, QC, Canada

Surface engineering plays a key role in enhancing the performance of next-generation titanium-based implantable medical devices. Incorporating bioactive agents into protective coating offers a promising strategy to tailor surface properties to improve biological responses after implantation. This study aims to develop PMMA–silica coatings containing calcium and silver phosphates in the surface layer, acting simultaneously as an anticorrosion barrier and a bioactive layer. PMMA–silica coatings were synthesized by combining the sol–gel process of tetraethylorthosilicate (TEOS) with the radical polymerization of methyl methacrylate (MMA) and 3-methacryloxypropyl trimethoxysilane (MPTS). Bioactive agents, including hydroxyapatite (HA), β-tricalcium phosphate (β-TCP), and silver phosphate (Ag₃PO₄), were dispersed in the PMMA–silica solution. The coatings were deposited onto Ti6Al4V substrates by immersion, resulting in uniform layers with thicknesses of up to 17 µm, free of cracks and exhibiting excellent adhesion strength (>14 MPa). The influence of the additives on the structural properties of the nanocomposites was analyzed using infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, thermal analysis, and contact angle measurements. Electrochemical impedance spectroscopy conducted in simulated body fluid (SBF, ISO 23317) confirmed the excellent anticorrosion performance of the modified coatings, showing an impedance modulus of up to 70 GΩ cm² after 100 days in SBF, which is four orders of magnitude higher than that of uncoated Ti6Al4V. Additionally, apatite crystal deposits observed after 28 days of immersion in SBF are an indicator of the in vivo bone bioactivity of the coatings. Biological evaluations revealed enhanced proliferation of SaOS-2 osteoblasts after 7 days of culture on coatings containing β-TCP or HA combined with Ag₃PO₄. These results highlight the potential of modified PMMA–silica coatings as highly promising materials for improving the bioactive and anticorrosive properties of Ti-based implants.

Acknowledgments: This research received financial support from the Brazilian funding agencies CNPq and CAPES.

9.20. The Development of Extreme Wettability Coatings to Combat the Spread of Bacterial Infections and Their Testing in Hospital Conditions

• Alexandre Emelyanenko, Ludmila Boinovich and Kirill A. Emelyanenko

• Frumkin Institute of Physical Chemistry and Electrochemistry Russian Academy of Sciences, 31-4 Leninsky prospect, 119071 Moscow, Russia

The use of materials with extreme wettability [1,2] may become one of the most promising strategies to combat the spreading of bacterial infections through touch surfaces not only in medical facilities but also in public areas, including educational institutions, supermarkets, and fitness centers. The extreme-wettability coatings have both a nonspecific bactericidal effect against various types of bacteria and several more specific mechanisms that work against certain strains depending on the type of metal. At the same time, such coatings are effective against various ways of spreading the bacterial cells, be it through the deposition of an aerosol created when patients cough or sneeze or through contact transfer via patients’ hands. In this work, we will briefly summarize the existing strategies for producing materials with extreme wettability by aqueous media and overview their main characteristics. Then, the mechanisms behind the antibacterial effect of these materials will be discussed in detail, along with an analysis of some examples of testing the antibacterial efficacy of extreme-wettability surfaces in hospital settings. We will also discuss the prospects for the wider use of such antibacterial materials not only in medical institutions, but also in shopping centers, educational institutions, in transport, and other places characterized by increased risks of infection-related contact transmission. This will minimize human losses during the spread of future bacterial pandemics. In particular, a 22-week study [2] of extreme-wettability copper-coated high-touch surfaces in a hospital environment showed that the frequency of contamination with various microorganisms was 2.7 times lower than that of control surfaces.

References

[1] Emelyanenko, A.M.; Makvandi, P.; Moradialvand, M.; Boinovich, L.B. Surface Innovations, 2024, 12, 360–379.

[2] Emelyanenko, A.M.; Omran, F.S.; Teplonogova, M.A. et al. Int. J. Mol. Sci., 2024, 25, 4471.

The research was financially supported by the Russian Science Foundation Grant #23-73-30004, https://rscf.ru/en/project/23-73-30004/.

9.21. Theoretical Assessment of Antimicrobial Properties of Silver Coating for Medical Applications

• Adrian Moraru and Fattima Al-Abedj

¹ 

Science and Engineering of Oxide Materials and Nanomaterials Department, Faculty of Chemical Engineering and Biotechnologies, National University of Science and Engineering POLITEHNICA Bucharest, Bucharest, Romania

² 

Extreme Light Infrastructure—Nuclear Physics, Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering, Bucharest-Magurele, Romania

³ 

Faculty of Medicine, University of Medicine and Pharmacy “Carol Davila” Bucharest, Bucharest, Romania

Silver-based biomaterials have excellent antimicrobial properties, as shown by experimental studies on bacterial cultures, viruses, and fungi. The properties of silver nanoparticles have attracted attention around the development of materials that efficiently utilize these characteristics. Thus, silver has been incorporated into many medical products, such as anticancer agents, controlled-release systems, coatings for orthopedic materials and medical devices, as well as bandages, etc.

The aim of this study is to simulate the antimicrobial properties of silver coatings and observe the influence of the morphology and thickness of the silver layer on these properties. To achieve this, the variation in time of the silver concentration and the concentration of bacterial cultures in the selected medium (agar in a Petri dish) were monitored. In this study, the diffusion of silver ions through agar and their interaction with Gram-positive (S. aureus, S. epidermidis) and Gram-negative (E. coli, K. pneumoniae) bacterial cultures was simulated.

According to preliminary data, particles with cubic and spherical morphology exhibit the best antimicrobial properties, with a silver concentration above the minimum inhibitory concentration for both Gram-positive and Gram-negative bacteria. These results indicate the applicability of simulations as a preliminary method for determining the optimal parameters for designing materials with medical applications.

9.22. Unlocking the Potential of Flaxseed Oil: Innovative Coating Technologies and Blending Techniques for Enhanced Stability and Health Benefits

• Azra Behroozi Farde Mogaddam ^1,2, Sodeif Azadmard-Damirchi ¹, Soraya Babaie ² and Azizeh Farshbaf-Khalili ²

¹ 

Department of Food Science and Technology, Faculty of Agriculture, University of Tabriz, Tabriz, Iran

² 

Physical Medicine and Rehabilitation Research Center, Aging Research Institute, Tabriz University of Medical Science, Tabriz, Iran

Introduction: Plant-derived oils and fats are estimated to constitute at least 79% of annual global oil production. Flaxseed oil, which is rich in omega-3 fatty acids, has been linked to the prevention and reduction of several serious health conditions, including cancer, diabetes, atherosclerosis, hypertension, eczema, gastrointestinal disorders, and cardiovascular diseases. Despite its numerous health benefits, flaxseed oil is susceptible to oxidation. The process of extracting flaxseed oil from flaxseeds yields an equivalent to 32–45% of the seed mass, with the oil containing 55–57% alpha-linolenic acid (ALA) and 15–18% linolenic acid (n-6). Mixing flaxseed oil with other oils, such as olive and sesame, can create a balanced fatty acid profile while preserving oxidative stability. However, during storage, the peroxide and anisidine values of these oil blends tend to increase.

Methods and Materials: Microencapsulation techniques have been developed to enhance the stability and use of flaxseed oil in food products.

Results: Flaxseed, packed with alpha-linolenic acid, lignans, and fiber, provides multiple health benefits. A regular intake of flaxseed may enhance lipid metabolism, reduce hypertension, regulate blood sugar, and mitigate insulin resistance. Scientific studies focus on protective processing methods like coating milled flaxseed with Arabic gum, ascorbic acid, and hydrogenated fats to minimize its oxidation. Microencapsulation shields oxidation-sensitive compounds in foods, improving their stability. The key methods used in microencapsulation include physical (spray/freeze drying), chemical (interfacial polymerization/cross-linking), and physico-chemical (ionic gelation/coacervation) techniques. Incorporating flaxseed oil into zein films boosts their tensile strength and moisture resistance, while maltodextrin with sodium caseinate demonstrated the optimal encapsulation performance. These strategies enable the effective integration of flaxseed into foods while preserving their nutritional potency and absorption.

Conclusions: As a result, the food industry can develop functional products that harness the health-promoting properties of flaxseed oil while ensuring product stability and quality.