Materials

21 pages, 33522 KB

Open AccessEditor’s ChoiceArticle

Microstructure and Properties of Cu-Ni-W-Si Gradient Coating on Copper Alloy by Laser Cladding

by Kaiyu You, Qi Zhong, Hanchang Ye, Yuxiang Jiang, Chenjiayue Ji, Haoran Ouyang, Pengyuan Zhai, Fengcheng Li and Zhenyang Cai

Materials 2026, 19(13), 2781; https://doi.org/10.3390/ma19132781 - 30 Jun 2026

Cited by 1 | Viewed by 300

Abstract

To enhance the surface hardness and wear resistance of copper alloy workpieces, a Cu-Ni-W-Si gradient coating was fabricated on a Cu-Cr-Zr alloy substrate using coaxial powder-feeding laser cladding technology. Employing surface macroscopic morphology, flaw detection results, and cross-sectional microstructure as evaluation methods, along [...] Read more.

To enhance the surface hardness and wear resistance of copper alloy workpieces, a Cu-Ni-W-Si gradient coating was fabricated on a Cu-Cr-Zr alloy substrate using coaxial powder-feeding laser cladding technology. Employing surface macroscopic morphology, flaw detection results, and cross-sectional microstructure as evaluation methods, along with the coating’s surface microhardness as a performance indicator, orthogonal experiments were sequentially conducted on the laser cladding process parameters for the Cu-Ni-10(W,Si) bottom layer and the Cu-Ni-20(W,Si) top layer. The optimized process parameters were identified as follows: a laser power of 4500 W (5000 W for the top layer), a scanning speed of 30 mm/s (60 mm/s for the top layer), and a scanning step of 2 mm. Subsequently, the phase composition and microstructure of the Cu-Ni-W-Si gradient coating were analyzed, and the microhardness distribution as well as the room-temperature friction and wear performance were evaluated. The results show that the coating achieves a hardness of 417 HV, which is 5.8 times higher than that of the substrate, and exhibits a wear rate of 3.52 × 10⁻⁴ mm³/Nm, corresponding to 49.1% of the substrate’s wear rate. The excellent performance of the coating is attributed to the favorable gradient metallurgical bonding between the coating and the substrate, as well as the presence of finely dispersed WSi₂ high-hardness wear-resistant phases within the coating. Full article

(This article belongs to the Special Issue Advances in Functional Coatings and Films for Thermal, Wear and Corrosion Protection)

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17 pages, 7588 KB

Open AccessEditor’s ChoiceArticle

Structural Characteristics and Properties of Zinc Coatings on Steel Structural Elements

by Małgorzata Witkowska, Marcin Kowalski, Joanna Kowalska and Kinga Chronowska-Przywara

Materials 2026, 19(13), 2727; https://doi.org/10.3390/ma19132727 - 25 Jun 2026

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Abstract

This paper presents the structural characterization of zinc coatings on S235JR steel elements. The study offers a novel and comprehensive assessment of zinc coatings applied to profiled steel elements through hot-dip galvanizing. It examines coatings formed under real industrial production conditions, providing practical [...] Read more.

This paper presents the structural characterization of zinc coatings on S235JR steel elements. The study offers a novel and comprehensive assessment of zinc coatings applied to profiled steel elements through hot-dip galvanizing. It examines coatings formed under real industrial production conditions, providing practical insight into their behavior on complex geometries. The characterization includes metallographic, mechanical, diffraction, and tribological tests. Metallographic observations revealed the layered structure of zinc coatings, consisting of the η, ζ, δ, and Γ phases, each with varying chemical compositions and microhardness. All coatings exhibited similar resistance to damage initiation; however, microscopic analysis revealed differences in their subsequent degradation. The thickest coating showed earlier formation of adhesive cracks, indicating increased stress concentration and a faster progression of damage. Full article

(This article belongs to the Special Issue Advanced Surface Engineering: Mechanisms, Properties, and Applications)

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19 pages, 3881 KB

Open AccessEditor’s ChoiceArticle

Mechanical Properties of 3D-Printed ABS Composites Reinforced with Multi-Scale Carbon/Kevlar Hybrid Fibers

by Shaoqi Dong, Shixian Li and Wanying Zhu

Materials 2026, 19(13), 2690; https://doi.org/10.3390/ma19132690 - 23 Jun 2026

Viewed by 424

Abstract

Fused deposition modeling (FDM) provides a flexible manufacturing route for continuous fiber-reinforced thermoplastic composites, but weak interlaminar bonding and the trade-off between load-bearing capacity and deformation capability still limit their structural applications. In this study, multi-scale carbon/Kevlar fiber hybridization was introduced into acrylonitrile [...] Read more.

Fused deposition modeling (FDM) provides a flexible manufacturing route for continuous fiber-reinforced thermoplastic composites, but weak interlaminar bonding and the trade-off between load-bearing capacity and deformation capability still limit their structural applications. In this study, multi-scale carbon/Kevlar fiber hybridization was introduced into acrylonitrile butadiene styrene (ABS)-based composites by combining continuous carbon fiber (CCF) or continuous Kevlar fiber (CKF) with short carbon fiber-filled ABS (ABS/SCF) or short Kevlar fiber-filled ABS (ABS/SKF). Four hybrid configurations and two continuous-fiber baseline composites were fabricated by FDM and evaluated through three-point bending tests, floating roller peel tests, peeled-surface SEM observations, and Rule-of-Mixtures-based hybrid effect analysis. The flexural results showed that short-fiber-filled matrices improved the flexural properties of both CCF- and CKF-based composites, but the degree of improvement depended on the fiber combination. Among the investigated configurations, CCF + ABS/SCF exhibited the highest flexural modulus and strength, which were 34.31% and 27.26% higher than those of CCF + ABS, respectively. For the CKF-based composites, CKF + ABS/SCF increased the flexural modulus and strength by 31.51% and 26.78%, compared with CKF + ABS, while maintaining the progressive deformation behavior associated with Kevlar reinforcement. The peel results showed that all hybrid composites had higher interlaminar peel resistance than their corresponding baselines, with increases ranging from 18.66% to 54.42%. The peeled-surface SEM observations indicated that the short-fiber-filled matrices changed the crack-propagation features, with more matrix tearing, fiber pull-out, and irregular peeling areas. The RoM-based comparison showed that the measured flexural properties of all hybrid configurations were higher than the corresponding RoM reference values. Overall, CCF + ABS/SCF was more suitable for improving stiffness and load-bearing capacity, whereas CKF + ABS/SCF showed a more balanced response in terms of flexural performance, interlaminar peel resistance, and progressive deformation behavior. Full article

(This article belongs to the Special Issue Structural Design and Mechanical Properties of Fiber Composites (Second Edition))

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12 pages, 6488 KB

Open AccessEditor’s ChoiceArticle

Utilization of Municipal Solid Waste Ash in Concrete Blends in Israel Part B: Combustion in a Semi-Industrial Incinerator

by Sarit Nov, Shay Barak, Haim Cohen and Yaniv Knop

Materials 2026, 19(13), 2686; https://doi.org/10.3390/ma19132686 - 23 Jun 2026

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Abstract

This study (Part B) examines the potential utilization of municipal solid waste (MSW) ash, produced in a semi-industrial incinerator in Israel, as a partial substitute for cement and natural sand in industrial concrete mixtures. The ash was produced at the temperature range 600–850 [...] Read more.

This study (Part B) examines the potential utilization of municipal solid waste (MSW) ash, produced in a semi-industrial incinerator in Israel, as a partial substitute for cement and natural sand in industrial concrete mixtures. The ash was produced at the temperature range 600–850 °C, and the ash was characterized using XRD and SEM to determine its mineralogical composition and morphology. The results indicate that ash composition is dominated by calcium-rich phases, with hatrurite (Ca₃SiO₅) representing approximately 51–66 wt.% of the identified crystalline phases, along with calcite, MgO, and silica phases. The ash consists of irregular, porous particles with a broad distribution. Concrete performance was evaluated in both fresh and hardened states. In terms of fresh concrete properties, it is observed that concrete containing ash showed improved workability, better workability retention, and better concrete density compared to concrete without ash. In terms of hardened concrete properties, the use of MSW ash as a partial sand replacement preserved the mechanical performance of the concrete, with compressive strength remaining within approximately 2% of the reference mixture. These findings suggest that semi-industrially produced MSW ash is more suitable as a fine aggregate replacement than as a supplementary cementitious material and represents a promising route for reducing landfill disposal and promoting circular economy practices in the construction industry. Full article

(This article belongs to the Special Issue Incorporating Advanced New or Recycled Materials in Reinforced Concrete Structures)

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14 pages, 3149 KB

Open AccessEditor’s ChoiceArticle

Anisotropic Graphene Oxide Aerogels for Vegetable Oil Absorption

by Daniel Ordóñez Oviedo, Nelly Maria Rosas-Laverde, Arturo Barjola, Enrique Giménez and Alina Iuliana Pruna

Materials 2026, 19(12), 2680; https://doi.org/10.3390/ma19122680 - 22 Jun 2026

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Abstract

Oil spills represent a critical environmental challenge. The wastewater treatment with porous sorbents presents the advantage of higher uptake and recyclability. In this work, highly porous and low-density three-dimensional reduced graphene oxide aerogels were obtained by hydrothermal reduction followed by lyophilization. The porosity [...] Read more.

Oil spills represent a critical environmental challenge. The wastewater treatment with porous sorbents presents the advantage of higher uptake and recyclability. In this work, highly porous and low-density three-dimensional reduced graphene oxide aerogels were obtained by hydrothermal reduction followed by lyophilization. The porosity and reduction degree of the aerogels were controlled by the addition of reducing species, namely ethylenediamine, and hydrothermal conditions. The aerogels were characterized using scanning electron microscopy, Raman spectroscopy, and energy-dispersive X-ray analysis. The sorption measurements were performed with vegetable oils, namely canola and olive oil, at varying operating temperatures. The morphological analysis revealed a well-defined porosity gradient along the aerogel length, along with a functionalization gradient. The sorption performance is highly dependent on their combined action. The maximum gravimetric absorption capacity was about 122 g g⁻¹ at room temperature, increasing to 156 g g⁻¹ at 60 °C, with the absorption rate increasing from about 1 g g⁻¹ s⁻¹ to 15 g g⁻¹ s⁻¹ within 10 s. These results demonstrate that anisotropic gradient aerogels could be obtained by simple tailoring of the synthesis conditions, and such aerogels could benefit the sorption of oils with higher viscosities in terms of rate, pore filling and retention. Full article

(This article belongs to the Section Carbon Materials)

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18 pages, 70867 KB

Open AccessEditor’s ChoiceArticle

Effect of La and Ce Microalloying on the Corrosion Resistance of 0.4Sb Low-Alloy Steel in a Harsh Marine Atmospheric Environment

by Qing Li, Xinyu Wang, Guowei Yang, Da Wei, Junjie Chen, Zhigao Wang, Jun Wang, Xiaojia Yang, Kui Xiao, Xiaogang Li and Zhong Li

Materials 2026, 19(12), 2685; https://doi.org/10.3390/ma19122685 - 22 Jun 2026

Viewed by 332

Abstract

In this study, low-alloy structural steels with different La and Ce contents were prepared via vacuum smelting and controlled rolling and controlled cooling technologies, and their microstructures were characterized. The influence of La and Ce on the corrosion resistance of low-alloy steels was [...] Read more.

In this study, low-alloy structural steels with different La and Ce contents were prepared via vacuum smelting and controlled rolling and controlled cooling technologies, and their microstructures were characterized. The influence of La and Ce on the corrosion resistance of low-alloy steels was compared through indoor cyclic-immersion accelerated tests simulating tropical marine atmospheres. The corrosion mechanism of low-alloy steels with different La and Ce contents in simulated tropical marine atmospheres was investigated using electrochemical measurements and corrosion product analysis. The results show that La and Ce improve the uniform corrosion resistance of low-alloy steels. With increasing La/Ce content, the corrosion current density decreased from 1.8936 × 10⁻⁶ A cm⁻² for 0LaCe to 1.29 × 10⁻⁶ A cm⁻² for 0.3LaCe, corresponding to a reduction of approximately 31.9%. This is attributed to the fact that La/Ce addition promotes rust layer stabilization and densification, as suggested by the evolution of major rust phases and the presence of La/Ce-related oxidized species. Meanwhile, alloying with La and Ce improves the cracking of the rust layer, reduces the number of pores, and stabilizes the rust layer structure. Full article

(This article belongs to the Special Issue Study on Electrochemical Behavior and Corrosion of Materials)

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25 pages, 1703 KB

Open AccessEditor’s ChoiceReview

Osteoimmunology-Driven Design of Dental Implant Materials: From Immune Response to Osseointegration

by Julia Kloc, Kinga Janusiewicz, Karolina Jędrzejczyk, Agnieszka Kijora, Aleksandra Jankowska, Marcelina Księżopolska-Markiewicz, Weronika Pająk, Jakub Kleinrok and Jacek Baj

Materials 2026, 19(12), 2627; https://doi.org/10.3390/ma19122627 - 18 Jun 2026

Viewed by 950

Abstract

The success of dental implantation depends on both mechanical stability and the host’s immune response to the implanted biomaterials. Osteoimmunology emphasizes that early immune responses at the implant-tissue interface are critical for bone healing and long-term osseointegration. The immune response primarily consists of [...] Read more.

The success of dental implantation depends on both mechanical stability and the host’s immune response to the implanted biomaterials. Osteoimmunology emphasizes that early immune responses at the implant-tissue interface are critical for bone healing and long-term osseointegration. The immune response primarily consists of immune cells, particularly macrophages, neutrophils, and lymphocytes, which interact with osteogenic cells through cytokine networks and signalling pathways, such as RANK/RANKL/OPG. Additionally, it modulates both bone formation and resorption. This review focuses on summarizing the mechanisms that shape the immune response around implants by dental implant materials. It describes mechanisms related to bulk composition, surface topography, and mechanical properties, and highlights macrophage polarization and the transition from inflammation to regeneration. The review discusses current immunomodulatory strategies, including bioactive surfaces, ion doping, nanopatterning, drug-releasing surfaces, and responsive materials, as well as advances enabled by additive manufacturing. The review also discusses experimental models used to study osteoimmunological interactions and the clinical significance of immune dysregulation in peri-implant diseases. The design of biomaterials based on osteoimmunology represents a shift toward immune-compatible implants that aim to improve regenerative outcomes and long-term implant success. Full article

(This article belongs to the Special Issue Advanced Biomaterials for Tissue Engineering and Dental Applications: Design, Fabrication and Characterization)

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25 pages, 5578 KB

Open AccessFeature PaperEditor’s ChoiceArticle

Optimizing Potassium-Based Activator Formulation for Balanced Reactivity, Flowability, Setting Time and Mechanical Performance of Alkali-Activated Materials

by Gulsen Nazerian, Jun Gu, Tine Tysmans and Hubert Rahier

Materials 2026, 19(12), 2604; https://doi.org/10.3390/ma19122604 - 17 Jun 2026

Viewed by 394

Abstract

Alkali-activated materials (AAMs) based on industrial by-products, such as ground granulated blast furnace slag (GGBFS), are increasingly considered sustainable alternatives to Ordinary Portland Cement (OPC) due to their lower environmental impact and favorable mechanical performance. Among the key parameters controlling the behavior of [...] Read more.

Alkali-activated materials (AAMs) based on industrial by-products, such as ground granulated blast furnace slag (GGBFS), are increasingly considered sustainable alternatives to Ordinary Portland Cement (OPC) due to their lower environmental impact and favorable mechanical performance. Among the key parameters controlling the behavior of alkali-activated systems, the chemical composition and modulus of the alkaline activator play critical roles in determining the reaction kinetics and material properties. This study investigates the influence of potassium silicate modulus (Ms), defined as the molar ratio of silica to alkali oxide (SiO₂/K₂O), on the reactivity, setting time, flowability, and mechanical properties of alkali-activated slag pastes. Potassium silicate solutions with moduli ranging from 1.0 to 2.5 were used as activators for GGBFS. Paste specimens with different activator moduli were prepared and cured at 20 °C and 75% relative humidity for mechanical testing. The results show that the activator modulus significantly affects the fresh properties, particularly at higher modulus values. Increasing the modulus delays reactivity and prolongs the setting time, whereas the flowability of the fresh paste decreases. Nevertheless, the flowability of the mixtures remained sufficient to allow proper penetration between open textile meshes, which is essential for textile-reinforced cement/concrete (TRC) applications. No clear systematic trends were observed in the mechanical properties, including the elastic modulus, flexural strength, and compressive strength. Full article

(This article belongs to the Special Issue Geopolymers and Alkali-Activated Materials: Preparation and Properties (Second Edition))

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14 pages, 1690 KB

Open AccessEditor’s ChoiceArticle

Tailoring PLA-Based Composite Membranes with Ionic Liquids for Efficient H₂/CO₂ Separation in Reforming Processes

by Dionysios Vroulias, Athina Nikolopoulou, Theophilos Ioannides and Vassilios Dracopoulos

Materials 2026, 19(12), 2567; https://doi.org/10.3390/ma19122567 - 13 Jun 2026

Viewed by 421

Abstract

Hydrogen (H₂), produced from syngas and the Water–Gas Shift reaction, plays a vital role as both an energy carrier and an essential industrial feedstock. This preliminary study examines the effect of incorporating ionic liquids into PLA membranes for the separation of [...] Read more.

Hydrogen (H₂), produced from syngas and the Water–Gas Shift reaction, plays a vital role as both an energy carrier and an essential industrial feedstock. This preliminary study examines the effect of incorporating ionic liquids into PLA membranes for the separation of hydrogen (H₂) from carbon dioxide (CO₂), aiming to provide a more energy-efficient alternative to the conventional Pressure Swing Adsorption process. Specifically, neat PLA and composite membranes containing cholinium-based ionic liquids at concentrations of 3% and 10% were fabricated. Their thermal properties and microstructural characteristics were systematically analyzed, alongside their gas separation performance. The most promising membrane was further evaluated under humid conditions to assess the impact of water presence. The PLA membrane incorporating 3% cholinium glycinate ionic liquid demonstrated the best performance, achieving a hydrogen permeability of 111 Barrer and an H₂/CO₂ selectivity of 8.2, surpassing the Robeson Upper Bound reported in 2008. However, the presence of water led to a decline in separation performance, indicating that effective water removal is necessary prior to membrane application in hydrogen purification. Full article

(This article belongs to the Special Issue Ionic Liquid-Based Materials: Fundamentals and Applications)

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16 pages, 3770 KB

Open AccessEditor’s ChoiceArticle

Quantum-Confined Stark Effect in Polar InGaN/GaN Quantum Wells of Different Widths Studied by Photoluminescence Under Hydrostatic Pressure

by Tadek Suski, Grzegorz Staszczak, Witold Trzeciakowski, Lukas Uhlig, Jannina Jacqueline Tepaß, Mateusz Hajdel and Grzegorz Muzioł

Materials 2026, 19(12), 2473; https://doi.org/10.3390/ma19122473 - 9 Jun 2026

Viewed by 385

Abstract

Low-temperature photoluminescence (PL) has been studied under hydrostatic pressure and varying excitation powers in three samples of single In_0.17Ga_0.83N quantum wells with different widths: 2.6 nm, 5.2 nm, and 10.4 nm. Transitions involving ground states were strong in the [...] Read more.

Low-temperature photoluminescence (PL) has been studied under hydrostatic pressure and varying excitation powers in three samples of single In_0.17Ga_0.83N quantum wells with different widths: 2.6 nm, 5.2 nm, and 10.4 nm. Transitions involving ground states were strong in the 2.6 nm well, weak in the 5.2 nm well, and absent in the 10.4 nm well. Pressure coefficients of PL lines have been used to estimate the electric field in the wells. In the widest well, the field seems to be fully screened (at high excitation powers). Simulations involving Poisson and Schrödinger equations allowed us to identify the experimental PL lines. Pressure evolution of the PL spectra agreed with the simulation. We present diagrams showing the dependence of the field in the well on pressure and on carrier concentration. In wide wells, these diagrams illustrate the transition from a 2D-like system to a 3D-like system. Full article

(This article belongs to the Special Issue Advances in Electronic and Photonic Materials)

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17 pages, 3876 KB

Open AccessEditor’s ChoiceArticle

Molecular Design of Underwater Adhesive Copolymers: Synergy Between Long-Chain Alkyl Crystallization–Melting Switching and Carboxyl Group Interfacial Interactions

by Han Liu and Lei Hou

Materials 2026, 19(11), 2407; https://doi.org/10.3390/ma19112407 - 5 Jun 2026

Viewed by 441

Abstract

Achieving strong adhesion in underwater or humid environments remains challenging because the interfacial hydration layer prevents direct contact between the adhesive and the substrate. Conventional adhesives typically fail under these conditions, so new strategies are needed to actively displace the water layer and [...] Read more.

Achieving strong adhesion in underwater or humid environments remains challenging because the interfacial hydration layer prevents direct contact between the adhesive and the substrate. Conventional adhesives typically fail under these conditions, so new strategies are needed to actively displace the water layer and create stable interfacial interactions. In this study, we prepared a series of copolymers with different monomer ratios via photocuring, using methacrylic acid (MAA) and stearyl methacrylate (SMA) as monomers. We focused on their thermal transition behavior and adhesion performance under both dry and underwater conditions. The results show that at an SMA molar fraction of 85%, the copolymer exhibits crystalline melting between 30 and 40 °C, where the storage modulus drops from approximately 10⁷ Pa to 10⁴ Pa, indicating a stiff-to-soft transition. Under dry conditions, this composition shows an adhesion strength of 1.67 MPa to glass, which remains 1.2 MPa underwater, and it can support a hanging load of 5 kg. The copolymer adheres well to glass and aluminum but shows weak adhesion to PTFE. After surface abrasion, the adhesion strength to glass increases to 1.6–1.8 MPa. In summary, the copolymer achieves effective underwater adhesion through the synergy of hydrophobic water displacement, thermally induced stiff-to-soft switching, and hydrogen bonding. Full article

(This article belongs to the Section Polymeric Materials)

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20 pages, 8477 KB

Open AccessEditor’s ChoiceArticle

Systematic Evaluation of Strain Rate and Environmental Conditions Effects on Stress Corrosion Cracking of an Al-Cu Alloy

by Sergio Lorenzi, Lorenzo Nani, Samuel Ferrari, Mattia Locatelli, Luca Gritti, Sara Bocchi and Marina Cabrini

Materials 2026, 19(11), 2414; https://doi.org/10.3390/ma19112414 - 5 Jun 2026

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Abstract

The aim of this study is to comprehensively investigate and quantify the effect of strain rate (SR) and environmental parameters on the stress corrosion cracking (SCC) behavior of a high-strength, aluminum–copper alloy. Slow strain rate (SSR) tests were carried out in air at [...] Read more.

The aim of this study is to comprehensively investigate and quantify the effect of strain rate (SR) and environmental parameters on the stress corrosion cracking (SCC) behavior of a high-strength, aluminum–copper alloy. Slow strain rate (SSR) tests were carried out in air at 25 °C, over a SR range from 10⁻⁴ to 10⁻⁷ s⁻¹ and controlled relative humidity (RH) between 40% and 80%. The influence of the pre-soaking period in 3.5 wt.% NaCl solution was also assessed. A major effect of pre-soaking was identified, as it was necessary for the onset of SCC. Increasing RH over 40% and decreasing SR below 10⁻⁵ s⁻¹ significantly intensified SCC susceptibility, leading to ductility loss up to 84%. SSR test results were supported by microstructural investigations, with particular emphasis on the role of second phases. Their electrochemical activity was examined by scanning Kelvin probe force microscopy (SKPFM), while intergranular corrosion (IGC) susceptibility was evaluated according to the ISO 11846 standard. The pronounced IGC susceptibility of the alloy led to predominantly intergranular fracture morphologies in cross-section peripheral areas after SSR testing. The results confirmed the synergistic effect among microstructure, IGC susceptibility and SCC behavior, identifying a critical window of mechanical and environmental parameters governing SCC. Full article

(This article belongs to the Special Issue Corrosion Behavior and Mechanical Properties of Metallic Materials (3rd Edition))

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22 pages, 3931 KB

Open AccessEditor’s ChoiceArticle

One-Pot Sr-Free LaFeO₃/CeO₂-Based Electrocatalytic Composites: Effect of Cerium and Lanthanum Interplay Between Perovskite and Fluorite

by Laura Valentino, Francesca Deganello, Leonarda Francesca Liotta, Giuseppe Marcì and Chiara Aliotta

Materials 2026, 19(11), 2361; https://doi.org/10.3390/ma19112361 - 2 Jun 2026

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Abstract

Perovskite-type oxides are among the most promising cathodes for intermediate-temperature solid oxide fuel cells (IT-SOFCs) due to their mixed ionic–electronic conductivity and compositional flexibility. Many high-performance cathodes rely on Sr substitution at the A-site, often associated with surface segregation and long-term degradation. In [...] Read more.

Perovskite-type oxides are among the most promising cathodes for intermediate-temperature solid oxide fuel cells (IT-SOFCs) due to their mixed ionic–electronic conductivity and compositional flexibility. Many high-performance cathodes rely on Sr substitution at the A-site, often associated with surface segregation and long-term degradation. In this work, we explore an alternative strategy based on defect engineering and phase interactions in Sr-free composites. Perovskite-fluorite composites based on LaFe_0.8Co_0.2O₃ were synthesized through a one-pot route designed to promote the formation of a perovskite phase and a limited amount of fluorite-type ceria. This approach allows the introduction of small fractions of Ce into the perovskite lattice, favoring the cooperative coexistence with La-doped CeO₂. Structural, microstructural and spectroscopic characterization indicates that Ce influences the crystallization pathway and composite defect chemistry. Variations in lattice parameters and Raman features suggest modifications of perovskite structure consistent with defect formation and lattice distortion. Reduction properties and electrical conductivity measurements indicate that Ce incorporation in the perovskite and oxide interaction affect charge transport and oxygen mobility. The electrochemical results demonstrate that the optimal trade-off between activation energy (Ea) and polarization resistance (Rp) is achieved for the sample, with a nominal cerium content, Ce/(La + Ce) of 0.16. Moreover, the electrochemical properties are found to correlate with the nominal cerium content, which regulates defect chemistry and the resulting composite composition. Overall, results suggest that the one-pot synthesis promotes beneficial interactions between the perovskite and ceria phases, allowing the development of Sr-free ferrite-based materials with enhanced functional properties, minimizing the amount of ceria in the composite. Full article

(This article belongs to the Special Issue Application of Electrocatalytic and Electrochemical Materials in Energy)

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24 pages, 10631 KB

Open AccessEditor’s ChoiceArticle

Non-Destructive Characterization of Cultural Heritage Materials Using a Modified Acoustic Resonance Approach

by Filip Pantelić, Miloš Radomir Vasić, Marko Stojanović, Anja Terzić, Bojan Miljević and Snežana Vučetić

Materials 2026, 19(11), 2291; https://doi.org/10.3390/ma19112291 - 28 May 2026

Viewed by 371

Abstract

This study explores non-destructive techniques for characterizing the mechanical properties of materials pertinent to cultural heritage, emphasizing the preservation of sample integrity. A modified acoustic resonance method (MARM), utilizing a two-microphone configuration, is introduced for the simultaneous, fully non-contact determination of dynamic elastic [...] Read more.

This study explores non-destructive techniques for characterizing the mechanical properties of materials pertinent to cultural heritage, emphasizing the preservation of sample integrity. A modified acoustic resonance method (MARM), utilizing a two-microphone configuration, is introduced for the simultaneous, fully non-contact determination of dynamic elastic modulus and damping (loss factor). The method is validated through comparison with the impulse excitation technique (IET) and ultrasonic pulse velocity testing (UT). The approach is applied to two material categories exhibiting contrasting porosities: dense natural stone and highly porous unfired clay. Results demonstrate strong concordance among all methods for stone, confirming the reliability of non-destructive techniques for homogeneous materials. Conversely, unfired clay displays greater variability attributable to its heterogeneous and porous nature, alongside increased damping. This investigation reveals that conventional modulus–strength correlations are not directly applicable to unfired clay. To address this, a simplified strength estimation model incorporating the estimated elastic modulus and porosity is proposed. The model achieves improved alignment with experimental data and delineates applicability boundaries for porous materials. The presented framework facilitates consistent, non-destructive evaluation of mechanical properties, with notable implications for the assessment and preservation of cultural heritage materials. Full article

(This article belongs to the Section Advanced Materials Characterization)

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10 pages, 1803 KB

Open AccessEditor’s ChoiceArticle

Impact of Printing Orientation and Printer Type on the Accuracy of 3D-Printed Dental Splints

by Mohammed Hammamy, Neeraj Surathu, Nitish Surathu, Nathaniel C. Lawson and Andrea C. Dardashtian

Materials 2026, 19(11), 2266; https://doi.org/10.3390/ma19112266 - 27 May 2026

Viewed by 549

Abstract

Additive manufacturing has expanded the fabrication of occlusal splints; however, the influence of printing technology and build orientation on accuracy remains unclear. This study evaluated the effect of printing technology (Liquid Crystal Display [LCD] and Digital Light Processing [DLP]) and build orientation (0°, [...] Read more.

Additive manufacturing has expanded the fabrication of occlusal splints; however, the influence of printing technology and build orientation on accuracy remains unclear. This study evaluated the effect of printing technology (Liquid Crystal Display [LCD] and Digital Light Processing [DLP]) and build orientation (0°, 45°, and 90°) on the trueness of additively manufactured occlusal splints under standardized conditions. A maxillary occlusal splint was digitally designed from a scanned typodont and used as the reference model. Specimens (n = 10/group) were fabricated using two LCD printers (Ackuretta SOL, Phrozen Mini 8K S) and one DLP printer (SprintRay Pro 95S) with a single photopolymer resin (KeySplint Soft). All samples were printed at 100 µm layer thickness and subjected to standardized post-processing. Trueness was assessed by comparing scanned splints to the reference STL using Geomagic Control X and expressed as root mean square (RMS) values. Data were analyzed using two-way ANOVA and Tukey post hoc tests (α = 0.05). Printing technology and build orientation significantly affected trueness (p < 0.001), with RMS values increasing as build orientation increased, and no significant interaction between factors (p > 0.05). LCD systems demonstrated lower RMS values than the DLP system across all orientations. Within the limitations of this study, both factors influenced trueness; however, all systems produced clinically comparable results, supporting the use of LCD technology as a cost-effective option for occlusal splint fabrication. Full article

(This article belongs to the Special Issue Advanced Biomaterials for Dental Applications (2nd Edition))

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26 pages, 34335 KB

Open AccessEditor’s ChoiceArticle

Investigating Process–Structure–Property Relationships in Large-Scale Additively Manufactured Carbon-Filled PETg

by Christopher Bock, Brett Ellis and Masoud Rais-Rohani

Materials 2026, 19(11), 2270; https://doi.org/10.3390/ma19112270 - 27 May 2026

Viewed by 511

Abstract

Properties of a material fabricated by large-scale additive manufacturing exhibit strong process dependence by way of processing and microstructure. This study seeks to experimentally evaluate this process–structure–property linkage for carbon-fiber-reinforced PETg. To facilitate this investigation, an experimental design involving eight different combinations of [...] Read more.

Properties of a material fabricated by large-scale additive manufacturing exhibit strong process dependence by way of processing and microstructure. This study seeks to experimentally evaluate this process–structure–property linkage for carbon-fiber-reinforced PETg. To facilitate this investigation, an experimental design involving eight different combinations of layer height, feed rate, bead spacing and screw speed in the printing process is considered. Forty-five microstructure specimens are excised and imaged to reveal the fiber orientation and porosity, and nearly 180 flexural samples are tested to evaluate their strength and stiffness. Measured mean values for modulus along the bead range from 13.3 to 18.6 GPa, and for strength, it is between 158 to 189 MPa. Mean values for the inter-layer stiffness range from 2.9 to 3.2 GPa, and for strength, it ranges between 31.4 and 45.0 MPa. Results indicate a strong relationship between screw speed and fiber orientation and between fiber orientation and stiffness and strength. Additional insights into the fracture behavior of the material are provided using high-speed photography of the moment of fracture and microscopy of the fracture surfaces. This work provides a cohesive process–structure–property dataset that can be used as a reference for validation of process–structure, structure–property, and process–structure–property models. Full article

(This article belongs to the Section Manufacturing Processes and Systems)

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24 pages, 10296 KB

Open AccessEditor’s ChoiceArticle

Sustainable Conversion of Pistachio Shells into Functional Biocarbons: Structural Evolution, Surface Properties, and Adsorptive Removal of Methyl Orange

by Barbara Charmas, Katarzyna Jedynak, Barbara Wawrzaszek and Lizaveta Tuflina

Materials 2026, 19(11), 2231; https://doi.org/10.3390/ma19112231 - 25 May 2026

Viewed by 340

Abstract

This study aimed to produce biocarbons from pistachio shells and estimate the effect of physical activation with CO₂ and overheated steam on their physicochemical, thermal, and adsorption properties in relation to methyl orange. Biocarbons were obtained by pyrolysis at 800 °C and [...] Read more.

This study aimed to produce biocarbons from pistachio shells and estimate the effect of physical activation with CO₂ and overheated steam on their physicochemical, thermal, and adsorption properties in relation to methyl orange. Biocarbons were obtained by pyrolysis at 800 °C and subsequently activated under different conditions. From the results, the type of activating agent substantially determined the development of pore structure and surface chemistry. CO₂ activation favored the formation of primarily microporous materials with a very large specific surface area, whereas steam activation led to a more open, hierarchical pore system with a greater pore volume and a larger contribution to external surface area. The most favorable textural properties were found for the samples PM-8-CO₂-3 and PM-8-H₂O-2. The FTIR, Raman, Boehm titration, CHN, SEM-EDS, and TG/DTG/DTA analyses confirmed that activation caused reconstruction of the carbon matrix, modification of the surface functional groups, and a decrease in thermal stability with increasing activation intensity. The adsorption studies proved that the sample PM-8-H₂O-2 exhibited the largest efficiency in methyl orange removal. The adsorption kinetics were best described by the pseudo-second-order model, whereas the equilibrium data were best fitted by the Freundlich model. The adsorption process was spontaneous and exothermic. Full article

(This article belongs to the Special Issue Advanced Adsorbent Materials: Preparation, Performance, Applications)

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45 pages, 6746 KB

Open AccessEditor’s ChoiceReview

Adhesives and Sealants in Packaging: Functional Roles and System-Level Classification (Part I)

by Calogero Volpe and Leonardo Pagnotta

Materials 2026, 19(11), 2210; https://doi.org/10.3390/ma19112210 - 24 May 2026

Cited by 1 | Viewed by 456

Abstract

Adhesives and sealants are critical yet still underrepresented components in packaging science. Existing reviews mainly address specific chemistries, sealing technologies, or application niches, whereas integrated analyses of adhesive and sealant families within a unified packaging-system framework remain limited. This review addresses this gap [...] Read more.

Adhesives and sealants are critical yet still underrepresented components in packaging science. Existing reviews mainly address specific chemistries, sealing technologies, or application niches, whereas integrated analyses of adhesive and sealant families within a unified packaging-system framework remain limited. This review addresses this gap by proposing a three-dimensional classification framework—functional role, material chemistry and activation mechanism, and performance constraints—that connects functional roles, processing routes, regulatory constraints, and circularity requirements. The framework is applied across natural, synthetic, hot-melt, pressure-sensitive, and tie-layer adhesives, as well as conventional thermoplastic, barrier-oriented, and biodegradable sealant systems. Special attention is given to hybrid systems operating at the boundary between bonding and sealing, and to the performance–recyclability trade-offs that arise in multilayer architectures. Structure–property–function relationships are analysed qualitatively with respect to bond and seal strength, seal initiation temperature, hot-tack behaviour, and end-of-life compatibility. Part I establishes the classification and functional groundwork for the two-part review; Part II will extend the analysis to quantitative performance data, advanced materials, and emerging technologies. Full article

(This article belongs to the Special Issue Packaging and Polymer-Based Materials)

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33 pages, 15100 KB

Open AccessEditor’s ChoiceArticle

Effects of Heat Treatment Procedures and Diamond Burnishing on Tensile Properties and Surface Integrity of Additively Manufactured 17-4PH Steel Cylindrical Parts

by Galya Duncheva, Jordan Maximov, Vladimir Dunchev, Angel Anchev, Vladimir Todorov, Yaroslav Argirov, Kalin Anastasov and Hristian Mitev

Materials 2026, 19(11), 2192; https://doi.org/10.3390/ma19112192 - 22 May 2026

Viewed by 512

Abstract

This article presents a new combined post-processing concept to improve the quality of laser powder bed fusion (LPBF) of 17-4PH stainless steel (SS) cylindrical parts fabricated from N₂-atomised LaserForm 17-4PH (B) powder. The concept is based on consecutive heat treatment procedures [...] Read more.

This article presents a new combined post-processing concept to improve the quality of laser powder bed fusion (LPBF) of 17-4PH stainless steel (SS) cylindrical parts fabricated from N₂-atomised LaserForm 17-4PH (B) powder. The concept is based on consecutive heat treatment procedures and diamond burnishing (DB) processes. A two-stage study was conducted. The first stage was an LPBF process experiment. The following combination of LPBF parameter values was selected after optimisation: a laser power of

P = 150 W

, laser scanning speed of v = 1200 mm/s, and layer thickness of

t = 40 μ m

. In the second stage, this combination was used to evaluate the effects of two heat treatment procedures (HT1 and HT2) and two DB processes (using burnishing forces of 100 N and 300 N) on the tensile properties and surface integrity of LPBF 17-4PH SS cylindrical samples. The HT2 procedure, including annealing

(1200^{\circ}

,

4 h)

, solution treatment (

1060^{\circ}

,

1 h)

, cooling (

{- 70}^{\circ} C, 2 h

), and ageing (

482^{\circ}

,

4 h

) led to yield limit, tensile strength, and Vickers hardness values of

Y L = 1071 M P a

,

T S = 1410 M P a

, and

523 H V,

respectively. The concept presented takes advantage of the combination of the transformation, precipitation and strain-hardening effects. The combined effect was most pronounced in the samples subjected to the HT2 procedure and subsequent DB (300 N), for which a retained austenite fraction of 6.93%, surface microhardness of

{563 H V}_{0.05}

and the maximum values of the compressive axial and hoop RSs of

- 1426.3 M P a

and

- 1095.9 M P a

, respectively, were measured. Full article

(This article belongs to the Special Issue Advanced Welding Technologies and Additive Manufacturing of Alloys and Metals (3rd Edition))

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30 pages, 11986 KB

Open AccessEditor’s ChoiceArticle

Electrical Resistance Activation of Embedded Fe-SMA Rebars in Pre-Cracked UHPFRC Beams: Internal Temperature Evolution and Calibrated Electro-Thermal Simulation

by Alireza Tabrizikahou, Jan Białasik, Karol Nowak, Krzysztof Lehmann, Grzegorz Trzmiel and Arkadiusz Dobrzycki

Materials 2026, 19(10), 2163; https://doi.org/10.3390/ma19102163 - 21 May 2026

Viewed by 438

Abstract

Iron-based shape memory alloy (Fe–SMA) rebars can generate internal prestress in cement-based members after restrained thermal activation; however, the temperature actually reached by embedded rebars in cracked UHPFRC is difficult to infer from exposed bar segments. This study investigates electrical resistance activation of [...] Read more.

Iron-based shape memory alloy (Fe–SMA) rebars can generate internal prestress in cement-based members after restrained thermal activation; however, the temperature actually reached by embedded rebars in cracked UHPFRC is difficult to infer from exposed bar segments. This study investigates electrical resistance activation of 4% prestrained Fe–SMA rebars embedded in pre-cracked UHPFRC beams and clarifies the activation-control problem by combining thermocouple measurements with a calibrated two-dimensional electro-thermal simulator. Twelve beams (150 × 150 × 600 mm) containing either Dramix 3D or Dramix 4D hooked steel fibers were first loaded in three-point bending to a mid-span displacement of 4 mm. The 4D series reached a 9.47% higher average pre-cracking load, confirming that fiber geometry modified the cracked state before heating. During activation, the exposed rebar segment reached 200 °C after approximately 77 s, whereas the embedded working segment reached the same target only after approximately 213 s; at that moment, the exposed segment was already close to 350 °C. The calibrated simulator reproduced the target activation time with an error of approximately 3 s and visualized the localized heat transfer from Fe–SMA to UHPFRC. The results demonstrate that activation control based only on exposed-bar temperature may cause under-activation of the embedded reinforcement, and that direct internal temperature monitoring is required for reliable Fe–SMA activation in cracked UHPFRC members. Full article

(This article belongs to the Special Issue Shape Memory Materials: Processing, Properties, and Applications)

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32 pages, 31177 KB

Open AccessEditor’s ChoiceReview

Engineering Nanomaterials for Next-Generation Electrochemical Food Safety Sensors: A Comprehensive Review

by Shakila Parveen Asrafali, Thirukumaran Periyasamy and Jaewoong Lee

Materials 2026, 19(10), 2170; https://doi.org/10.3390/ma19102170 - 21 May 2026

Viewed by 408

Abstract

Rising global demand for safe, high-quality foods has accelerated the development of rapid, sensitive, and cost-effective analytical technologies for detecting harmful substances and quality markers. Electrochemical sensors have emerged as promising tools for food safety monitoring due to their high sensitivity, fast response, [...] Read more.

Rising global demand for safe, high-quality foods has accelerated the development of rapid, sensitive, and cost-effective analytical technologies for detecting harmful substances and quality markers. Electrochemical sensors have emerged as promising tools for food safety monitoring due to their high sensitivity, fast response, portability, and affordability compared with conventional laboratory methods. This review highlights recent advances in nanostructured electrochemical sensors for detecting key food analytes, including antioxidants, mycotoxins, allergens, and flavor compounds in diverse food matrices. It examines advanced nanomaterials such as metal oxides, MXenes, doped carbon nitrides, and noble metal-decorated graphene, which enhance sensor performance through improved surface area, conductivity, and electrocatalytic activity. Integrated with screen-printed or glassy carbon electrodes, these materials achieve ultra-low detection limits, wide linear ranges, and strong selectivity in complex food systems. The review also explores next-generation applications such as NFC-enabled smart packaging for continuous, non-invasive monitoring across the supply chain. Emerging trends in miniaturization, multiplex sensing, and artificial intelligence are discussed, along with key challenges in translating laboratory innovations into practical commercial solutions for global food safety. Full article

(This article belongs to the Special Issue Advances in Nanomaterials for Electrochemical Sensor and Biosensor Applications)

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13 pages, 2995 KB

Open AccessEditor’s ChoiceArticle

Influence of Nickel Content and Heat Treatment Parameters on Kinetics of Crystallisation, Magnetic Properties and Brittleness of Nanocrystalline Fe-Ni-B Alloys Obtained by Ultra-Rapid Annealing with Joule Heating

by Jarosław Ferenc, Zofia Czyżewska, Maciej Kowalczyk, Krzysztof Sielicki and Dariusz Oleszak

Materials 2026, 19(10), 2157; https://doi.org/10.3390/ma19102157 - 21 May 2026

Viewed by 556

Abstract

Metallic glasses can be transformed into nanocrystalline–amorphous alloys via controlled crystallisation with fast nucleation and slow grain growth. This can be achieved either through appropriate chemical composition of amorphous precursors or by applying ultra-rapid annealing (URA). Typically, heating between preheated copper blocks is [...] Read more.

Metallic glasses can be transformed into nanocrystalline–amorphous alloys via controlled crystallisation with fast nucleation and slow grain growth. This can be achieved either through appropriate chemical composition of amorphous precursors or by applying ultra-rapid annealing (URA). Typically, heating between preheated copper blocks is used to ensure the URA conditions. In this work, ribbons were heated by an electric current flowing along their length, and the temperature was monitored using pyrometers. The investigated alloys were Fe_86-xNi_xB₁₄ (at. %), where x = 4, 6 or 10. Properly adjusted isothermal annealing at 380–410 °C for 1–20 s induced crystallisation, with the nanocrystalline bcc-Fe(Ni) phase occupying 0–55% of the volume. With increasing annealing time, the coercive field increased from 9 A/m in the amorphous state to 25 A/m and 17 A/m for x = 4 and x = 10, respectively. Transmission electron microscopy confirmed that samples annealed at higher temperatures for shorter times exhibited smaller grain sizes compared to those annealed at lower temperatures for longer times, which resulted in improved magnetic softness. An increase in nickel content reduced coercivity, improved ductility, and offered a wider window for the choice of annealing temperature. Full article

(This article belongs to the Special Issue Advances in Magnetic Materials and Applications)

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20 pages, 6365 KB

Open AccessEditor’s ChoiceArticle

Topological Weyl and Nodal Line Half-Metals in Two-Dimensional van der Waals Material EuOX (X = F, Cl, Br, I)

by Sheng-Hsiung Hung and Horng-Tay Jeng

Materials 2026, 19(10), 2154; https://doi.org/10.3390/ma19102154 - 21 May 2026

Viewed by 475

Abstract

Two-dimensional magnetic materials with an atomic-thick layered structure have long been a focal point in condensed matter physics owing to the intrinsic long-range magnetic order, the monolayer limit with high tunability and potential in nano-scale spintronics. In this study, we report a novel [...] Read more.

Two-dimensional magnetic materials with an atomic-thick layered structure have long been a focal point in condensed matter physics owing to the intrinsic long-range magnetic order, the monolayer limit with high tunability and potential in nano-scale spintronics. In this study, we report a novel family of two-dimensional (2D) materials, EuOX (where X = F, Cl, Br, I), displaying 2D half-metallicity with topological properties. Specifically, the spin-up conducting channel demonstrates metallic behavior, while the spin-down channel exhibits an insulating band gap at the Fermi level. The presence of Weyl points and nodal lines coexists in the spin-up conductive channel of EuOX monolayers. These topological properties, alongside the half-metallic behavior, evolve systematically with the strong-correlation Hubbard U. These findings provide crucial insights into the design of 2D topological spintronic devices, offering a promising platform for future spintronic applications in the nano scale. Full article

(This article belongs to the Section Materials Physics)

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21 pages, 11838 KB

Open AccessEditor’s ChoiceArticle

Process Strategies Enabling Selective Polymer Valorization from Textile Fiber Blends

by Diana Smarandache, Bruno Godinho, Marina Matos, Susana C. Pinto, Cătălina Ionescu, Nicoleta Cioateră, Artur Ferreira and Nuno Gama

Materials 2026, 19(10), 2100; https://doi.org/10.3390/ma19102100 - 16 May 2026

Viewed by 446

Abstract

The increasing complexity of textile waste, particularly blended fibers, represents a major challenge for conventional recycling approaches. This study proposes a selective valorization strategy for mixed textile waste streams by applying tailored chemical recycling routes to individual fiber type. Preliminary tests identified suitable [...] Read more.

The increasing complexity of textile waste, particularly blended fibers, represents a major challenge for conventional recycling approaches. This study proposes a selective valorization strategy for mixed textile waste streams by applying tailored chemical recycling routes to individual fiber type. Preliminary tests identified suitable methodologies for each fiber type: dissolution–precipitation for acrylic (poly(acrylonitrile)—PAN), acidolysis for nylon, glycolysis for polyester (PeS) and acetylation for cotton. Structural characterization confirmed that the incorporation of recycled products did not significantly change the chemical structure or crystallinity of the resulting materials. Furthermore, thermal analysis revealed comparable or slightly improved thermal stability in most recycled systems. Additionally, mechanical performance was observed to vary depending on the polymer type. Recycled acrylic and cellulose acetate showed reduced ductility, while nylon exhibited increased stiffness due to possible recrystallization effects. In contrast, PeS displayed enhanced elongation at break, suggesting increased chain mobility or plasticization effects. Overall, the results demonstrate that selective chemical valorization is a promising route for the efficient recycling of complex textile waste, enabling the recovery of high-quality materials with retained functional properties. Full article

(This article belongs to the Special Issue Advanced Materials for Circularity: Recycling of Polymer Blends and Composites)

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15 pages, 5177 KB

Open AccessEditor’s ChoiceArticle

Influence of Particle Size and Mineralogical Composition on the Mechanical and Tribological Properties of Resin-Regolith-Composites for Non-Structural Applications

by Nicola Calisi, Stefano Caporali and Rosa Taurino

Materials 2026, 19(10), 2066; https://doi.org/10.3390/ma19102066 - 15 May 2026

Viewed by 430

Abstract

The development of resin-regolith composites represents a promising In Situ Resource Utilization (ISRU) strategy for future lunar missions. While unsuitable for primary habitat construction due to the payload cost of transporting polymers from Earth, these composites offer a highly efficient solution for manufacturing [...] Read more.

The development of resin-regolith composites represents a promising In Situ Resource Utilization (ISRU) strategy for future lunar missions. While unsuitable for primary habitat construction due to the payload cost of transporting polymers from Earth, these composites offer a highly efficient solution for manufacturing non-structural, everyday items (e.g., containers, tools, and plant cultivation pots) directly on the Moon via mold–casting. This approach significantly reduces the volume and mass of pre-formed plastic payloads. In this work, the influence of the particle size distribution of a lunar highland simulant (LHS-1E) on the mechanical properties of epoxy-based composites was systematically investigated for such applications. First, the regolith-to-resin ratio was optimized for castability, establishing a maximum regolith content of 60 wt.%. Then, four different size fractions of the simulant were prepared by sieving (>200 µm, 200–100 µm, 100–50 µm, and <50 µm), and composite samples were cast maintaining this optimal ratio. X-ray microtomography revealed that using larger particles (>200 µm) increased composite porosity, whereas smaller fractions promoted more compact structures. Three-point bending tests showed that intermediate particle sizes (200–100 µm and 100–50 µm) led to enhanced flexural strength, while the smallest particles (<50 µm) decreased mechanical performance, likely due to a lower basalt content in this finer fraction. Finally, ball-on-disk tribological analyses highlighted that composites made with larger particles (>200 µm) exhibited superior wear resistance, whereas particle size had negligible effects on the coefficient of friction. Overall, the results demonstrate that both particle size and mineralogical composition significantly influence the performance of regolith–epoxy composites, providing essential guidelines for the in situ manufacturing of functional, non-structural objects for lunar outposts. Full article

(This article belongs to the Section Advanced Composites)

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28 pages, 3739 KB

Open AccessEditor’s ChoiceReview

Corrosion Behaviour in CO₂ Pipeline Transport: A Review of the Impact of Condensates and Impurities

by Luca Gritti, Denny Coffetti, Lorenzo Nani, Sergio Lorenzi and Marina Cabrini

Materials 2026, 19(10), 2048; https://doi.org/10.3390/ma19102048 - 14 May 2026

Cited by 1 | Viewed by 683

Abstract

The high emissions of carbon dioxide (CO₂) into the atmosphere have driven the development of carbon capture, transport, and storage (CCTS) technologies. These focus on capturing CO₂ from industrial exhaust gases and transporting it through existing pipeline networks. Although various [...] Read more.

The high emissions of carbon dioxide (CO₂) into the atmosphere have driven the development of carbon capture, transport, and storage (CCTS) technologies. These focus on capturing CO₂ from industrial exhaust gases and transporting it through existing pipeline networks. Although various capture techniques are available, they may introduce impurities such as O₂, N₂, Ar, H₂O, NH₃, and others into the CO₂ stream. These contaminants can significantly alter the thermophysical behaviour of the fluid, making the phase behaviour predictions, reliable for pure CO₂, much more complex. Pressure and temperature variations along pipelines can induce unexpected phase transitions, affecting fluid composition and potentially triggering corrosion. This review examines the formation of condensates within pipelines and their role in initiating corrosion phenomena, with a focus on top of the line corrosion (TLC) and conventional CO₂-induced corrosion (sweet corrosion). The main literature findings highlight how phase changes and altered fluid composition due to corrosion processes can significantly intensify degradation mechanisms during CO₂ transport. Full article

(This article belongs to the Special Issue Corrosion and Materials in Interacting Systems)

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20 pages, 5516 KB

Open AccessEditor’s ChoiceArticle

Development and Performance Assessment of Single- and Double-Layer TbAG:Ce and YAG:Ce Composite Scintillators on GAGG:Ce Substrates for Optimized α–γ Discrimination and Pulse-Shape Analysis

by Abdellah Bachiri, Agnieszka Syntfeld-Każuch, Vitalii Gorbenko, Sandra Witkiewicz-Lukaszek, Tetiana Zorenko, Yurii Syrotych, Lukasz Adamowski, Lukasz Swiderski, Vasyl Stasiv, Yaroslav Zhydachevskyy and Yuriy Zorenko

Materials 2026, 19(10), 2001; https://doi.org/10.3390/ma19102001 - 12 May 2026

Viewed by 591

Abstract

In this work, we report the fabrication and characterization of single-film and double-film composite epitaxial garnet structures based on single-crystalline films (SCFs) and bulk single-crystal (SC) scintillators for enhanced α–γ discrimination in mixed radiation fields. These composite scintillators consist of TbAG:Ce and YAG:Ce [...] Read more.

In this work, we report the fabrication and characterization of single-film and double-film composite epitaxial garnet structures based on single-crystalline films (SCFs) and bulk single-crystal (SC) scintillators for enhanced α–γ discrimination in mixed radiation fields. These composite scintillators consist of TbAG:Ce and YAG:Ce SCFs grown by liquid-phase epitaxy (LPE) on Czochralski-grown Gd₃Ga_2.5Al_2.5O₁₂ (GAGG:Ce) bulk SC substrates. Single- and double-film architectures were designed to optimize the energy absorption and pulse-shape discrimination (PSD) performance for low-penetrating α-particles and high-energy γ-rays. Energy calibration was performed using different γ-ray sources (⁵⁷Co, ⁵¹Cr, and ¹³⁷Cs), enabling the conversion of detector signals to a calibrated electron-equivalent energy scale (keVee). Integration gates were systematically optimized, yielding maximum figures of merit (FOM) of 1.4 for the GAGG:Ce SC substrate, 1.9 for the single-film composite, and 5.0 for the double-film composite, demonstrating a progressive improvement in α–γ discrimination with increasing structural complexity. Two-dimensional PSD density maps reveal well-separated α and γ events, with the highest separation observed for the double-film composite. These results indicate that the engineering of LPE-grown composites provides tunable scintillation decay profiles, enhanced temporal separation, and increased light yields, making them promising candidates for applications such as mixed radiation field detection, dosimetry, and radiation monitoring. Full article

(This article belongs to the Section Optical and Photonic Materials)

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19 pages, 4766 KB

Open AccessEditor’s ChoiceArticle

Experimental Evaluation of the Mechanical Healing Performance of Precast Concrete Incorporating Hybrid Capsules Under Load Reapplication for Smart Construction Material

by Yong Jic Kim, Sung-Rok Oh, Myounghwi Kim and Hyung-Suk Kim

Materials 2026, 19(10), 2003; https://doi.org/10.3390/ma19102003 - 12 May 2026

Viewed by 353

Abstract

This study experimentally evaluates the mechanical healing performance of precast concrete incorporating hybrid capsules under load reapplication conditions. Hybrid capsule systems are defined as self-healing systems that combine solid capsules (SCs) and liquid capsules (LCs), to enable multi-scale crack healing. In this study, [...] Read more.

This study experimentally evaluates the mechanical healing performance of precast concrete incorporating hybrid capsules under load reapplication conditions. Hybrid capsule systems are defined as self-healing systems that combine solid capsules (SCs) and liquid capsules (LCs), to enable multi-scale crack healing. In this study, four mix proportions (HC-0, HC-1, HC-3, and HC-5), corresponding to 0%, 1%, 3%, and 5% replacement of fine aggregate by volume with hybrid capsules, were prepared. The hybrid capsules consisted of SCs and LCs in a fixed ratio of 7:3. Among the mixtures, a representative intermediate content (3%) was selected to examine the feasibility of mechanical recovery compared to plain concrete, rather than to determine an optimal dosage. Mechanical recovery was evaluated through compressive and flexural strength tests after preloading and healing periods. The results confirm that the incorporation of hybrid capsules enables partial recovery of mechanical properties after damage. These findings provide preliminary experimental evidence of the feasibility of hybrid capsule systems in precast concrete. Further studies are required to investigate the influence of capsule content and to establish optimal mixture conditions. Full article

(This article belongs to the Special Issue Self-Healing Materials for Smart Manufacturing Systems)

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13 pages, 10636 KB

Open AccessEditor’s ChoiceArticle

Mechanism Research on Thieno-Fused Bis-BODIPY Bifunctional Photosensitizers

by Yuejia Wang, Di Wang, Xinyu Chen, Yishan Sun, Guoguo Shi and Jianfang Cao

Materials 2026, 19(10), 1987; https://doi.org/10.3390/ma19101987 - 11 May 2026

Viewed by 500

Abstract

This study is dedicated to the development of novel boron-dipyrromethene (BODIPY)-based photosensitizers, focusing on investigating the regulatory mechanism of introducing different electron-donating groups at the α-position on the photosensitizing performance of thieno-bis-BODIPY derivatives, aiming to provide a theoretical basis for cancer photodynamic therapy [...] Read more.

This study is dedicated to the development of novel boron-dipyrromethene (BODIPY)-based photosensitizers, focusing on investigating the regulatory mechanism of introducing different electron-donating groups at the α-position on the photosensitizing performance of thieno-bis-BODIPY derivatives, aiming to provide a theoretical basis for cancer photodynamic therapy (PDT). Five thieno-bis-BODIPY molecules (FD1-FD5) were constructed by connecting two BODIPY units via a thiophene π-bridge and introducing various substituents at the α-position of their phenyl groups. Systematic theoretical studies revealed that unilaterally substituted molecules exhibit superior photophysical properties compared to their bilaterally substituted counterparts. The key mechanisms involve structural planarization, increased electrostatic potential difference, and the formation of hybrid LE/CT characteristics in the excited state, all of which collectively promote the intersystem crossing (ISC) process. Specifically, the pyrrole-substituted FD4 exhibits the highest ISC efficiency due to its stronger electron-donating ability and greater molecular planarity, and it is predicted to possess a stronger singlet oxygen generation capability than the methoxy-substituted FD2 while maintaining fluorescence emission. In contrast, bilateral substitution leads to structural distortion, which favors fluorescence emission, as seen in FD5 which exhibits the longest absorption wavelength. This research elucidates the key mechanisms for enhancing ISC and photosensitizing performance from the perspectives of electronic structure and excited-state characteristics, providing theoretical guidance for overcoming limitations such as insufficient tissue penetration in traditional BODIPY photosensitizers and clarifying structure–activity relationships. Full article

(This article belongs to the Section Materials Chemistry)

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29 pages, 42206 KB

Open AccessEditor’s ChoiceArticle

Acoustic Source Localisation of Crack Initiation During Laser-Based DED: Experimental Validation and Challenges

by Md Jonaet Ansari, Elias J. G. Arcondoulis, Anthony Roccisano, Christiane Schulz, Thomas Schläfer and Colin Hall

Materials 2026, 19(10), 1967; https://doi.org/10.3390/ma19101967 - 10 May 2026

Viewed by 409

Abstract

This study evaluates the feasibility of airborne acoustic source localisation (ASL) for in situ crack localisation in industrial laser-based directed energy deposition (DED-LB/M) fabricated structures. A four-microphone array combined with a Generalised Cross-Correlation with Phase Transform (GCC-PHAT) algorithm was used to estimate crack [...] Read more.

This study evaluates the feasibility of airborne acoustic source localisation (ASL) for in situ crack localisation in industrial laser-based directed energy deposition (DED-LB/M) fabricated structures. A four-microphone array combined with a Generalised Cross-Correlation with Phase Transform (GCC-PHAT) algorithm was used to estimate crack positions from time differences of arrival (TDOAs) extracted from raw acoustic emissions during multi-layer single-track fabrication. Prior to experimentation, the microphone array geometry was numerically optimised under industrial placement constraints by introducing controlled TDOA perturbations and minimising three-dimensional localisation uncertainty using alpha-shape volume analysis. Experimental validation was performed on six-layer single-track structures, with estimated crack positions compared against post-process microscopic measurements. Localisation errors ranged from 12 to 68 mm in the X-direction, 0.7–32 mm in the Y-direction, and 5–100 mm in the Z-direction. While horizontal localisation demonstrated centimetre-scale accuracy for most cracks, depth estimation exhibited greater variability. The results confirm that airborne ASL can provide meaningful spatial information regarding crack formation during DED-LB/M. However, localisation performance remains sensitive to TDOA estimation accuracy, microphone array constraints, and the complex acoustic environment inherent to the process. This work demonstrates the industrial feasibility of ASL for in situ crack investigation while highlighting the need for further advancements in array design and signal processing to achieve robust three-dimensional defect localisation in additive manufacturing systems. Full article

(This article belongs to the Special Issue Additive and Subtractive Manufacturing of Advanced Material: Modeling and Surface Integrity)

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28 pages, 4810 KB

Open AccessEditor’s ChoiceArticle

Recycled Polypropylene Composites Reinforced with Microcellulose Fibres and Microcellulose-Derived Biochar: Thermal, Rheological and Mechanical Performance

by Wiktor Wyderkiewicz, Justyna Miedzianowska-Masłowska, Anna Sowińska-Baranowska and Marcin Masłowski

Materials 2026, 19(10), 1942; https://doi.org/10.3390/ma19101942 - 9 May 2026

Viewed by 601

Abstract

The mechanical recycling of mono-material biaxially oriented polypropylene (BOPP) packaging films produces recycled polypropylene (rPP) with degraded properties, limiting its use in higher-performance applications. This study investigates rPP reinforcement with 6–12 µm microcellulose fibres (MCFs, 2–10 pbw) and microcellulose-derived biochar (BC, 5–20 pbw), [...] Read more.

The mechanical recycling of mono-material biaxially oriented polypropylene (BOPP) packaging films produces recycled polypropylene (rPP) with degraded properties, limiting its use in higher-performance applications. This study investigates rPP reinforcement with 6–12 µm microcellulose fibres (MCFs, 2–10 pbw) and microcellulose-derived biochar (BC, 5–20 pbw), characterized by DSC, TGA/DTG, MVR/MFR, temperature-dependent rheology, mechanical testing and water contact angle (WCA) measurements. Both fillers acted as heterogeneous nucleating agents, shifting crystallization by up to 4 °C and increasing crystallinity by 2–4%. MCF introduced an additional low-temperature degradation step, whereas BC increased onset and peak degradation temperatures by up to 20 °C and increased char yield. Low MCF loadings increased MVR/MFR by 20–25% and reduced melt viscosity, while BC decreased flow indices by up to 50% and stiffened the melt. Tensile and flexural moduli increased by 15–25% with MCF and 40–50% with BC, with a stiffness–toughness trade-off at the highest BC contents. MCF reduced the water contact angle to 63.0° at 10 pbw, while BC increased it to 108.1° at 20 pbw, indicating opposite effects on surface wettability. Converting a single cellulosic feedstock into fibrous or carbonised fillers enables bio-based upgrading of rPP, in line with circular economy principles. Full article

(This article belongs to the Special Issue Advanced Polymer Matrix Nanocomposite Materials (3rd Edition))

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13 pages, 2279 KB

Open AccessEditor’s ChoiceArticle

One-Pot Synthesis of PtBi-Co_X Alloys for Electrochemical Nitrate Reduction to Ammonia

by Yingfei Liu, Yuxuan Wang, Xiyuan Sun, Chong Peng, Zhe Pang, Dafu Zhao, Kefeiyang Hu, Jiaqian Que, Xingbo Huang and Yong Liu

Materials 2026, 19(10), 1953; https://doi.org/10.3390/ma19101953 - 9 May 2026

Viewed by 395

Abstract

The electrochemical nitrate reduction reaction (NO₃RR) represents a promising strategy for wastewater remediation and sustainable ammonia (NH₃) production. However, its practical application is hindered by low selectivity and competition from the hydrogen evolution reaction (HER). Herein, a series of [...] Read more.

The electrochemical nitrate reduction reaction (NO₃RR) represents a promising strategy for wastewater remediation and sustainable ammonia (NH₃) production. However, its practical application is hindered by low selectivity and competition from the hydrogen evolution reaction (HER). Herein, a series of PtBi-Co_X (X = 4.9, 5.3, and 6.1) ternary alloy nanoplates was synthesized via a one-pot method with tunable Co content. Structural characterization indicates that Co incorporation does not significantly alter the hexagonal crystal structure of the PtBi phase. Electrochemical measurements reveal that the NO₃RR performance varies with PtBi-Co_X (X = 4.9, 5.3, 6.1), with PtBi-Co_5.3 exhibiting the optimal balance of activity and selectivity among the studied samples. At −0.5 V vs. RHE, it achieves a Faradaic efficiency (FE) of 97.75 ± 0.75% and an NH₃ yield rate of 9.33 ± 0.50 mg h⁻¹ mg_cat⁻¹ under the tested conditions. In addition, the catalyst exhibits relatively suppressed HER activity compared to samples with higher Co content, along with good stability. These findings provide useful insights into the design of PtBi-based ternary alloy catalysts for efficient nitrate reduction. Full article

(This article belongs to the Special Issue Sustainable Electrochemical and Chemical Synthesis of Functional Materials)

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21 pages, 1390 KB

Open AccessEditor’s ChoicePerspective

Calcination of Ca-Based Sorbents in the Presence of Steam for Sorption-Enhanced Gasification Applications

by William A. González, Susanna Nilsson, Diego Fuentes-Cano, Alicia Ronda and Alberto Gómez-Barea

Materials 2026, 19(10), 1959; https://doi.org/10.3390/ma19101959 - 9 May 2026

Viewed by 531

Abstract

The calcination kinetics of limestone and dolomite under conditions relevant to sorption-enhanced gasification (SEG) were investigated: mild temperature (775–850 °C), low CO₂ partial pressure (0.05–0.10 bar), and a steam-rich (H₂O balance) atmosphere. Experiments with two Ca-based sorbents (limestone and dolomite) [...] Read more.

The calcination kinetics of limestone and dolomite under conditions relevant to sorption-enhanced gasification (SEG) were investigated: mild temperature (775–850 °C), low CO₂ partial pressure (0.05–0.10 bar), and a steam-rich (H₂O balance) atmosphere. Experiments with two Ca-based sorbents (limestone and dolomite) were conducted in a fluidized bed reactor to assess both initial calcination kinetics and multicycle deactivation during 10 cycles under SEG carbonation conditions at 650 °C. Dolomite exhibited markedly higher calcination rates than limestone, which is consistent with the structural modifications induced by MgCO₃ decomposition and the presence of MgO, resulting in a slightly lower apparent activation energy (115.96 kJ mol⁻¹ for dolomite compared to 120.27 kJ mol⁻¹ for limestone). Both sorbents showed a strong sensitivity to the deviation from the equilibrium CO₂ partial pressure, with reaction orders near 2. The presence of steam was confirmed to have a significant catalytic effect, accelerating the first-cycle calcination rate compared to dry N₂ conditions. Sorbent deactivation caused by sintering was more pronounced at higher temperatures and CO₂ pressures. Dolomite showed significantly less deactivation, compared to limestone, which can be attributed to the increase in structural stability due to the presence of MgO. The kinetics obtained in this work contribute to the design of stable SEG based on dual fluidized bed reactors, particularly to assist in the selection of calcination operating conditions to minimize sorbent deactivation and in the development of stable CO₂-sorbents. Full article

(This article belongs to the Section Energy Materials)

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14 pages, 3013 KB

Open AccessEditor’s ChoiceArticle

Enhanced Aging Stability of Ordered Mesoporous Silica Materials Synthesized via True Liquid Crystal Templating—A Small-Angle X-Ray Scattering Study

by Xiangyin Tan, Boshra Atwi, Huy Bui Duc, Michael R. Buchmeiser and Frank Giesselmann

Materials 2026, 19(10), 1923; https://doi.org/10.3390/ma19101923 - 8 May 2026

Viewed by 465

Abstract

The long-term structural stability of ordered mesoporous silica (OMS) materials—specifically the durability of their pore architecture and pore lattice over time—is critical for their performance in catalysis, separation, drug carrier and nanoconfinement applications. SBA-15-type silica materials are synthesized via two different routes, namely [...] Read more.

The long-term structural stability of ordered mesoporous silica (OMS) materials—specifically the durability of their pore architecture and pore lattice over time—is critical for their performance in catalysis, separation, drug carrier and nanoconfinement applications. SBA-15-type silica materials are synthesized via two different routes, namely the conventional “liquid crystal templating” (LCT) and the much less common “true liquid crystal templating” (TLCT) of micellar structures formed by the amphiphilic block copolymer Pluronic P123 in water. Here, we report that SBA-15 materials age very differently depending on the synthesis route: Under ambient conditions, OMS materials obtained via the LCT route undergo significant structural changes over time, especially in microporous regions, while SBA-15 materials obtained via the TLCT route show less or even no structural changes even after a year of storage. We attribute this enhanced aging stability of TLCT materials to their narrow mesopore size distribution and their much lower degree of microporosity. Full article

(This article belongs to the Section Porous Materials)

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28 pages, 12481 KB

Open AccessEditor’s ChoiceArticle

Quantitative Damage Detection and Evolution in Composite Structures Using Digital Image Correlation, Machine Learning, and Peridynamics

by Tomas Vaitkūnas, Elena Jasiūnienė, Justas Griškevičius, Vykintas Samaitis and Paulius Griškevičius

Materials 2026, 19(10), 1917; https://doi.org/10.3390/ma19101917 - 7 May 2026

Viewed by 485

Abstract

Structural health monitoring (SHM) of composite structures using surface strain fields measured by digital image correlation (DIC) has been widely demonstrated; however, accurate damage quantification remains challenging. This study proposes a hybrid framework integrating finite element (FE) modeling, machine learning (ML), and peridynamics [...] Read more.

Structural health monitoring (SHM) of composite structures using surface strain fields measured by digital image correlation (DIC) has been widely demonstrated; however, accurate damage quantification remains challenging. This study proposes a hybrid framework integrating finite element (FE) modeling, machine learning (ML), and peridynamics (PD). A CFRP specimen with a notch was subjected to cyclic loading, and damage evolution was monitored using DIC and validated by ultrasound measurements. A validated FE model generated synthetic strain-field datasets for ML training, enabling defect detection and quantitative characterization directly from surface strains. The trained models achieved high accuracy, including perfect notch detection and low prediction errors. A calibrated PD model captured internal damage evolution and fatigue behavior. The combined DIC–ML–PD approach enables accurate, non-contact damage identification and prognosis, supporting physics-informed digital twins for composite structures. Full article

(This article belongs to the Special Issue Intelligent Damage Detection of Materials and Structural Health Monitoring Technology)

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14 pages, 6596 KB

Open AccessEditor’s ChoiceArticle

Conformal SiNx Coating on Carbon Nanotubes via Transient UV–Ozone Functionalization and Two-Step Atomic Layer Deposition

by Young Woo Kang, Haneul Kim, Inseo Lee, Yongkyung Kim, In-Sung Park and Jinho Ahn

Materials 2026, 19(10), 1919; https://doi.org/10.3390/ma19101919 - 7 May 2026

Viewed by 559

Abstract

A conformal SiNx coating on carbon nanotubes (CNTs) was achieved by combining transient UV–ozone surface functionalization with a two-step atomic layer deposition (ALD) process. UV–ozone treatment gradually increased the defect density of CNTs, with the I_D/I_G ratio increasing from 0.05 [...] Read more.

A conformal SiNx coating on carbon nanotubes (CNTs) was achieved by combining transient UV–ozone surface functionalization with a two-step atomic layer deposition (ALD) process. UV–ozone treatment gradually increased the defect density of CNTs, with the I_D/I_G ratio increasing from 0.05 for pristine CNTs to 0.25 after 7 min of exposure, while the overall fibrous CNT network remained intact. However, prolonged UV–ozone exposure beyond 10 min led to a sharp increase in the I_D/I_G ratio to 0.46, accompanied by structural degradation of the CNT membrane. Hydroxyl (-OH), epoxy (C-O-C), and carbonyl (C=O) groups were introduced by UV–ozone treatment and were partially removed during subsequent high-temperature processing. Accordingly, direct high-temperature ALD resulted in incomplete SiNx coverage of the CNTs, suggesting insufficient nucleation. A two-step ALD process, consisting of several cycles of low-temperature nucleation at 100 °C followed by high-temperature growth at 700 °C, enabled more conformal deposition of SiNx on CNTs. In addition, both annealing and ALD reduced the defect level toward that of pristine CNTs, supporting the transient nature of UV–ozone-induced functionalization. Full article

(This article belongs to the Special Issue Advances in Atomic Layer Deposition Process, Applications and Modeling)

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11 pages, 2028 KB

Open AccessEditor’s ChoiceArticle

Synergistic Chemical and Field-Effect Passivation Inhibits Sn²⁺ Oxidation and Non-Radiative Recombination in Tin–Lead Perovskite Solar Cells

by Jiahao Liu, Xucheng Wang, Pan Li, Huiyan Chen, Xing Tang, Weidong Lin, Ye Yuan and Xuehui Xu

Materials 2026, 19(10), 1914; https://doi.org/10.3390/ma19101914 - 7 May 2026

Viewed by 631

Abstract

Narrow-bandgap tin–lead (Sn–Pb) perovskite solar cells (PSCs) are essential for high-performance tandem photovoltaics, yet their operational stability and efficiency suffer from spontaneous Sn²⁺ oxidation, interfacial defects, and non-radiative recombination. Current passivation strategies often provide only a single modification mode and struggle to [...] Read more.

Narrow-bandgap tin–lead (Sn–Pb) perovskite solar cells (PSCs) are essential for high-performance tandem photovoltaics, yet their operational stability and efficiency suffer from spontaneous Sn²⁺ oxidation, interfacial defects, and non-radiative recombination. Current passivation strategies often provide only a single modification mode and struggle to adequately stabilize Sn²⁺ without introducing charge-transport barriers. Here, we introduce morpholine acetate (MPAC) as a novel interfacial passivator to achieve synergistic chemical and field-effect passivation in Sn–Pb perovskites. The acetate group of MPAC coordinates with undercoordinated metal cations, suppressing Sn²⁺ oxidation and minimizing defect states. Simultaneously, the morpholine moiety forms an interfacial dipole layer that aligns energy levels to facilitate charge extraction. Consequently, MPAC-modified PSCs achieve a champion power conversion efficiency of 22.64%. Under continuous AM 1.5G illumination without optical filters (xenon lamp, 65 °C, open-circuit conditions), the unencapsulated devices maintain over 90% of their initial efficiency after 192 h, providing a promising route to balance performance and durability. Full article

(This article belongs to the Special Issue Advanced Optoelectronic Materials and Functional Devices: Development, Characterization, and Application)

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15 pages, 17267 KB

Open AccessEditor’s ChoiceArticle

Microwave-Sintered Lunar Regolith Bricks for Lunar Infrastructure: Fracture Behavior, Tribological Performance, and Electromagnetic Wave Transmission

by Kelei Zhu, Juntao Guo, Qiqi Ning, Zhaobo Han, Longxiang Xu, Zhen Liu, Bo Gao and Jinping Li

Materials 2026, 19(9), 1907; https://doi.org/10.3390/ma19091907 - 6 May 2026

Viewed by 708

Abstract

Microwave-sintered lunar regolith bricks are promising candidates for in situ construction of lunar infrastructure, where structural load-bearing capacity and multifunctional performance are simultaneously required. Currently, there remains a research gap concerning the service performance of microwave-sintered lunar soil bricks under predictable load-bearing, wave-transparent, [...] Read more.

Microwave-sintered lunar regolith bricks are promising candidates for in situ construction of lunar infrastructure, where structural load-bearing capacity and multifunctional performance are simultaneously required. Currently, there remains a research gap concerning the service performance of microwave-sintered lunar soil bricks under predictable load-bearing, wave-transparent, and friction working conditions. In this study, lunar bricks were fabricated at different microwave sintering temperatures, and the effects of temperature on their microstructure and engineering properties were systematically investigated. The sample sintered at 1000 °C achieved a density of 2.96 g/cm³ and a compressive strength of 260 MPa. Combined experimental observations and numerical simulations revealed a typical brittle fracture behavior, primarily governed by residual porosity within the material. Tribological tests showed a low wear rate of 6.51 × 10⁻⁵ mm³/(N·m), indicating good wear resistance and potential applicability for lunar road paving. Dielectric measurements in the X-band (8.2–12.4 GHz) demonstrated a high electromagnetic wave transmittance ranging from 49.8% to 94.6%, suggesting suitability for communication-related or protective wall structures. These results demonstrate that microwave sintering effectively enhances the densification of lunar regolith while enabling the coordinated optimization of mechanical, tribological, and electromagnetic properties, providing practical guidance for the design of multifunctional materials for lunar infrastructure construction. Full article

(This article belongs to the Section Construction and Building Materials)

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18 pages, 2217 KB

Open AccessEditor’s ChoiceArticle

Grain-Size-Dependent Hydrogen Evolution and Oxygen Evolution Reaction Behavior of a Non-Equiatomic Fe₄₁Mn₂₅Ni₂₄Co₈Cr₂ High-Entropy Alloy

by Hee-Tae Jeong and Woo Jin Kim

Materials 2026, 19(9), 1899; https://doi.org/10.3390/ma19091899 - 5 May 2026

Viewed by 627

Abstract

The grain-size dependence of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) behavior was systematically investigated in a non-equiatomic Fe₄₁Mn₂₅Ni₂₄Co₈Cr₂ high-entropy alloy. Six fully recrystallized specimens spanning grain sizes from 5.1 to 197 [...] Read more.

The grain-size dependence of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) behavior was systematically investigated in a non-equiatomic Fe₄₁Mn₂₅Ni₂₄Co₈Cr₂ high-entropy alloy. Six fully recrystallized specimens spanning grain sizes from 5.1 to 197 μm, produced by high-ratio differential speed rolling (HRDSR) and controlled annealing, were tested in 1 M KOH. Differential local Tafel-slope analysis revealed distinct and asymmetric grain-size-dependent behavior for the two half-reactions. For HER, the local Tafel slope at −3 mA cm⁻² showed the clearest correlation with log(d/μm) among the HER descriptors examined in the present dataset (R² = 0.682), indicating that grain-size effects were most clearly expressed in the near-onset to intermediate current-density regime. For OER, finer-grained specimens consistently exhibited more favorable apparent performance: the overpotential at 10 mA cm⁻² increased with log(d/μm) (R² = 0.715; slope = 1.09 × 10⁻² V dec⁻¹), whereas the current density at an overpotential of 0.33 V decreased with grain size (j_0.33; R² = 0.787). Overall, OER showed stronger and more consistent grain-size dependence than HER. These results identify grain size as a useful empirical microstructural descriptor of apparent electrocatalytic response in this composition-fixed bulk HEA system and show that microstructural control provides a practical route for tuning alkaline HER and OER behavior. Full article

(This article belongs to the Special Issue Advances in Catalytic Materials and Their Applications)

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28 pages, 2182 KB

Open AccessEditor’s ChoiceArticle

Magnetic Biocomposite Based on Aspen Biochar, Sodium Alginate, and Phaffia rhodozyma Yeast for Efficient Removal of Methylene Blue from Aqueous Solutions

by Paweł Staroń, Gabriela Gaik and Jarosław Chwastowski

Materials 2026, 19(9), 1894; https://doi.org/10.3390/ma19091894 - 4 May 2026

Viewed by 609

Abstract

The aim of this study was to produce and characterize a magnetic biocomposite based on aspen biochar, sodium alginate, and Phaffia rhodozyma yeast biomass, as well as to evaluate its suitability for removing methylene blue (MB) from aqueous solutions. The sorbent structure was [...] Read more.

The aim of this study was to produce and characterize a magnetic biocomposite based on aspen biochar, sodium alginate, and Phaffia rhodozyma yeast biomass, as well as to evaluate its suitability for removing methylene blue (MB) from aqueous solutions. The sorbent structure was confirmed by FTIR, XRD, and SEM, demonstrating successful immobilization of biotic components in an amorphous polymer matrix. Kinetic studies demonstrated a rapid process, with dynamic equilibrium established after 180 min. Experimental data from equilibrium studies (3 h and 24 h) were analyzed using the Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich models. The theoretical maximum sorption capacity (q_d) determined was 39.31 mg/g, with higher sorption values observed for 24 h confirming the contribution of intrapore diffusion and yeast biosorption activity. In temperature-effect studies, the highest process efficiency (q_e = 1.43 mg/g) was observed at 25 °C, while its decrease at 35 °C indicated the exothermic nature of the phenomenon and the thermal sensitivity of the biological structure. VSM analysis revealed superparamagnetic properties of the composite (Ms = 9.3 A·m²/kg), which enabled full phase separation. Regeneration studies demonstrated that despite the high efficiency of mineral acids, the use of ethanol as an eluent allows for maintaining the structural integrity of the sorbent and its effective use in at least four cycles. The results indicate that the developed biocomposite is a promising, low-cost, and easily recoverable alternative to conventional sorbents in industrial wastewater treatment technologies. Full article

(This article belongs to the Special Issue Next-Generation Sorbent Materials: From Fundamentals to Applications)

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14 pages, 15026 KB

Open AccessEditor’s ChoiceArticle

Electrospun Poly(vinylpyrrolidone)/Thymus vulgaris L. Mats for the Protection of Fresh Berries Against Spoilage

by Erika Adomavičiūtė, Egidijus Griškonis, Visvaldas Varžinskas and Virginija Jankauskaitė

Materials 2026, 19(9), 1874; https://doi.org/10.3390/ma19091874 - 1 May 2026

Viewed by 629

Abstract

The use of non-biodegradable plastic food packaging materials has become a major environmental concern. These plastics release chemicals and microplastics during degradation, harming wildlife and entering the food chain, posing risks to both environmental and human health. This study aimed to evaluate electrospun [...] Read more.

The use of non-biodegradable plastic food packaging materials has become a major environmental concern. These plastics release chemicals and microplastics during degradation, harming wildlife and entering the food chain, posing risks to both environmental and human health. This study aimed to evaluate electrospun poly(vinylpyrrolidone) (PVP) mats incorporating natural antibacterial Thymus vulgaris L. extract (TE) and natural crosslinker citric acid (CA) as alternative food packaging materials. Packaging mats with TE and/or CA combinations in PVP were evaluated for their structural, chemical, optical, and shelf-life-enhancing effects on blueberries. The results show that dissolving PVP in TE extract and adding CA in PVP ethanol-water or TE-based solutions significantly affected the viscosity and conductivity of the electrospinning solutions, thereby influencing the morphology of electrospun mats. FTIR analysis confirmed the incorporation of TE into the polymer and indicated CA induced hydrogen bonding, interactions that may reduce the polymer chain mobility and increase the brittleness of the electrospun mat. In tests with blueberries, it was estimated that the commonly used traditional food film minimized blueberry weight loss, whereas the porous electrospun PVP and PVP/TE mats allowed greater moisture release and preserved better visual quality by reducing wrinkling and dehydration. Overall, electrospun PVP-based mats functionalized with TE show promise as sustainable food packaging materials that balance moisture management with product appearance. Full article

(This article belongs to the Special Issue Functional/Structural Polymers and Composites Produced by the Addition of Plant Biomass or Waste Materials Using Various Production Technologies)

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26 pages, 15987 KB

Open AccessEditor’s ChoiceArticle

Thin Copper Foils: From Electrodeposition Conditions to Adhesion Performances

by Ivana O. Mladenović, Željko Radovanović, Dana G. Vasiljević-Radović, Rastko Vasilić, Miloš Vorkapić, Predrag Živković and Nebojša D. Nikolić

Materials 2026, 19(9), 1838; https://doi.org/10.3390/ma19091838 - 29 Apr 2026

Viewed by 728

Abstract

Cathodic electrodeposition of copper on molybdenum and stainless-steel substrates has been investigated with the aim of examining their potential to produce thin copper foils (TCFs). Copper in the form of a thin film was electrodeposited galvanostatically from the acidic sulfate electrolyte without and [...] Read more.

Cathodic electrodeposition of copper on molybdenum and stainless-steel substrates has been investigated with the aim of examining their potential to produce thin copper foils (TCFs). Copper in the form of a thin film was electrodeposited galvanostatically from the acidic sulfate electrolyte without and with an addition of suppressor/activator additives, such as chloride ions, polyethylene glycol 6000 and 3–mercapto–1–propanesulfonic acid. The cathodes and electrodeposited Cu films were characterized by SEM, AFM, and XRD techniques, while the adhesion of Cu films, as a crucial parameter in the production of Cu foils, was estimated by a lab-made prototype of a bending test machine made by applying additive technology. The adhesion parameter named “critical cycle number” (n_c), which defines the minimal number of cycles leading to a delamination (separation) of the film from the cathode was used for assessing the adhesion features of the films. The easiest delamination, i.e., the smallest n_c, showed nanocrystalline films obtained with the addition of all additives, whereupon the values were significantly smaller than the values obtained for microcrystalline films obtained without and with a partial combination of the additives. The easy delamination of the nanocrystalline films indicated that both substrates have a high potential for application in the production of TCFs. Full article

(This article belongs to the Special Issue Advances in Electrodeposition of Thin Films and Alloys)

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18 pages, 4310 KB

Open AccessEditor’s ChoiceArticle

An Investigation of the Influence of the Sequence of Laser Texturing and Heat Treatment Processes on the Coefficient of Friction of X165CrMoV12 Steel

by Yavor Sofronov, Boyan Dochev, Antonio Nikolov, Krum Petrov, Valentin Mishev, Rayna Dimitrova, Milko Yordanov, Milko Angelov, Georgi Todorov and Krassimir Marchev

Materials 2026, 19(9), 1781; https://doi.org/10.3390/ma19091781 - 28 Apr 2026

Viewed by 523

Abstract

The effect of nanosecond laser modification on X165CrMoV12 tool steel before and after heat treatment was investigated. Three laser texturing modes were applied to the studied material, with the variables being the frequency used and the pulse energy: 50 kHz/pulse energy 0.9 mJ, [...] Read more.

The effect of nanosecond laser modification on X165CrMoV12 tool steel before and after heat treatment was investigated. Three laser texturing modes were applied to the studied material, with the variables being the frequency used and the pulse energy: 50 kHz/pulse energy 0.9 mJ, 100 kHz/pulse energy 0.45 mJ, and 150 kHz/pulse energy 0.3 mJ. The other parameters of laser texturing were power—90%; speed—500 mm/s; hatching angle—0° (horizontal), +60°/−60° (or equivalent 120°), and +30°/−30° (or equivalent 150°); and Hatching Distance—0.02 mm. The surface laser modification process aims to obtain a homogeneous and adaptive surface relief optimizing the operational properties of the working surfaces of the parts under dry contact friction conditions. The influence of the used laser modification modes on the roughness class of the obtained surfaces, the structure of the formed modified surface and the friction coefficient was studied. The comparative analysis showed that the lowest roughness class (Ra—4.123 µm) was obtained when using an operating frequency of 50 kHz. The obtained friction coefficient values were lowest in the following sequence of processes: laser texturing and subsequent thermal treatment. The lowest friction coefficient (µ = 0.0041) was registered in the test bodies processed with a mode in which the operating frequency was 50 kHz and the pulse energy was 0.9 mJ, after which they were subjected to thermal treatment according to the used cycle. In this processing sequence, no diffusion-related defects (decarburization) were observed on the surface layer of the tested steel. Full article

(This article belongs to the Special Issue Enhanced Properties of Advanced Materials via Surface Modification and Composite Coatings)

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28 pages, 7162 KB

Open AccessEditor’s ChoiceArticle

Effect of Heating/Cooling Rate and Temperature on Microstructure and Electrical Properties of Sputter-Deposited PZT Thin Films Crystallized by Conventional Furnace Annealing

by Manfred Wich, Jan Helmerich, Philipp Ott, Oliver Ambacher and Stefan Johann Rupitsch

Materials 2026, 19(9), 1782; https://doi.org/10.3390/ma19091782 - 28 Apr 2026

Viewed by 1781

Abstract

Lead zirconate titanate (PZT) is a widely used material for applications in microsensors, actuators, and transducers. Due to its high piezoelectric coefficient, large dielectric constant, and strong polarization capability near the morphotropic phase boundary (Zr/Ti ≈ 52/48), it is considered one of the [...] Read more.

Lead zirconate titanate (PZT) is a widely used material for applications in microsensors, actuators, and transducers. Due to its high piezoelectric coefficient, large dielectric constant, and strong polarization capability near the morphotropic phase boundary (Zr/Ti ≈ 52/48), it is considered one of the most attractive materials for micro-electromechanical systems (MEMS). These advantageous material properties strongly depend on the PZT layer’s microstructure and crystallinity, which are primarily determined by the choice of seed layer, deposition conditions, and the post-deposition annealing treatment that promotes the formation of the PZT’s perovskite phase. In this contribution, sputter-deposited PZT thin films were crystallized by conventional furnace annealing (CFA) to evaluate the effect of heating/cooling rates (1 °C·min⁻¹–7 °C·min⁻¹) within a temperature range of 450 °C to 700 °C on structural, electrical, and ferroelectric properties, with consideration of the seed layer preparation. We characterized the materials’ properties by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and measurements of the ferroelectric hysteresis, capacitance, and leakage current. All samples annealed at temperatures of at least 500 °C fully crystallized into the perovskite phase, independently of the heating/cooling rate. The best ferroelectric performance was achieved at 550 °C with a 1 °C·min⁻¹ heating/cooling rate, yielding a saturation polarization of 82.8 µC·cm⁻² and a remnant polarization of 36.9 µC·cm⁻² under a maximum applied field of 300 kV·cm⁻¹. Full article

(This article belongs to the Section Thin Films and Interfaces)

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36 pages, 2476 KB

Open AccessEditor’s ChoiceReview

Biodegradable Metals and Corrosion Control: Challenges, Limits and New Opportunities for Innovating in Orthopedic Fixations

by Abdelhakim Cherqaoui, Carlo Paternoster and Diego Mantovani

Materials 2026, 19(9), 1789; https://doi.org/10.3390/ma19091789 - 28 Apr 2026

Cited by 3 | Viewed by 1018

Abstract

Biodegradable metals represent a paradigm shift in orthopedic fixation by providing temporary mechanical support synchronized with bone healing while eliminating long-term complications associated with permanent implants. Conventional bioinert alloys, including stainless steels, Ti-based alloys, and Co-Cr alloys, exhibit high elastic moduli that induce [...] Read more.

Biodegradable metals represent a paradigm shift in orthopedic fixation by providing temporary mechanical support synchronized with bone healing while eliminating long-term complications associated with permanent implants. Conventional bioinert alloys, including stainless steels, Ti-based alloys, and Co-Cr alloys, exhibit high elastic moduli that induce stress shielding and often require secondary removal surgeries. In response, resorbable metallic systems based on Mg, Zn, and Fe have emerged as promising alternatives. Among these, Fe-Mn-C alloys stand out for load-bearing applications due to their exceptional strength-ductility balance governed by twinning-induced plasticity mechanisms, tunable degradation behavior, and intrinsic magnetic resonance imaging compatibility through austenitic phase stabilization. Focusing on Fe-Mn-C alloys, this review critically examines the metallurgical design principles underlying stacking fault energy optimization, phase stability, and Mn-controlled electrochemical behavior. Processing innovations, such as additive manufacturing, are discussed as tools to architecture porosity, refine microstructure, and accelerate degradation by graded designs while preserving mechanical structural support during healing. Hybrid metallic-bioactive systems, surface functionalization strategies, and functionally graded porous architectures were evaluated as advanced approaches to enhance osteointegration and modulate degradability. Despite these advances, significant barriers remain for clinical translation. Persistent discrepancies between in vitro and in vivo degradation rates, often attributed to biological encapsulation and degradation product accumulation, complicate lifetime prediction. Localized corrosion at microstructural heterogeneities such as twin boundaries and phase interfaces can undermine structural reliability under load-bearing conditions. Moreover, predictive multi-physics modeling frameworks capable of coupling electrochemical kinetics, mechanical loading, microstructural evolution, and bone remodeling remain underdeveloped, limiting reliable safety-margin estimation. Regulatory progress is further hindered by the absence of standardized testing protocols specifically tailored to Fe-based biodegradable alloys, including harmonized degradation rate windows, validated corrosion-mechanics coupling methodologies, and clinically defined Mn ion release thresholds. This review aims to discuss whether Fe-based alloys, especially Fe-Mn-C alloys, can transition from promising laboratory materials to clinically viable next-generation orthopedic implants capable of delivering patient-specific, mechanically compatible, and biologically synchronized temporary fixation. Full article

(This article belongs to the Special Issue Corrosion, Fatigue and Corrosion Protection of Metals and Their Alloys in Various Environments (2nd Edition))

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31 pages, 3684 KB

Open AccessEditor’s ChoiceReview

A Circular Material Value Retention Framework for Agricultural By-Product Valorisation

by Roxane Alizad, Yousef Haddad and Konstantinos Salonitis

Materials 2026, 19(9), 1796; https://doi.org/10.3390/ma19091796 - 28 Apr 2026

Viewed by 425

Abstract

While valorisation pathways are increasingly promoted as sustainable solutions, their ability to genuinely minimise environmental harm and contribute to long-term material circularity remains uneven. This study systematically identifies and maps existing valorisation routes across the EU and UK, with particular attention to their [...] Read more.

While valorisation pathways are increasingly promoted as sustainable solutions, their ability to genuinely minimise environmental harm and contribute to long-term material circularity remains uneven. This study systematically identifies and maps existing valorisation routes across the EU and UK, with particular attention to their environmental performance and economic viability through a material value retention lens. A literature review highlights a spectrum of practices—from soil amendment and composting to bioenergy recovery and bio-based construction materials—each offering different sustainability benefits but varying significantly in their capacity to preserve material quality and function. To address the absence of robust comparative approaches, this paper introduces a novel evaluative framework centred on intrinsic material value retention, a key principle in sustainable and circular material systems. Building on established scholarship, the framework provides a structured means of comparing valorisation options based on how effectively they conserve material properties, particularly in terms of the material’s structural and functional values, and enable high-value reuse. Supported by a dedicated classification tool and a set of guiding questions refined through expert interviews, the framework complements existing environmental assessment methods by foregrounding material circularity. In doing so, it supports more integrated, holistic decision-making for the development of a resilient and sustainable circular bioeconomy. This research is intended for academic audiences and may also be of relevance to industry practitioners. Full article

(This article belongs to the Section Green Materials)

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30 pages, 1378 KB

Open AccessEditor’s ChoicePerspective

Modeling of Biomechanical and Functional Parameters of Hydrogel–Cell Composites Fabricated by 3D Bioprinting Using AI-Supported Approach

by Izabela Rojek, Maciej Gniadek, Jakub Kopowski, Tomasz Kloskowski and Dariusz Mikołajewski

Materials 2026, 19(8), 1637; https://doi.org/10.3390/ma19081637 - 19 Apr 2026

Viewed by 583

Abstract

3D bioprinting of hydrogel–cell composites requires simultaneous consideration of the biomechanical properties of the printed structures, the construct’s geometric stability, and conditions conducive to cell survival and function. Hydrogel cross-linking techniques and their kinetics play a key role in this process, determining the [...] Read more.

3D bioprinting of hydrogel–cell composites requires simultaneous consideration of the biomechanical properties of the printed structures, the construct’s geometric stability, and conditions conducive to cell survival and function. Hydrogel cross-linking techniques and their kinetics play a key role in this process, determining the time of shape fixation, the mechanical strength of the structures, and the mechanical environment in which the cells are located immediately after printing. The relationships between bioprinting parameters, material properties, cross-linking strategies, and the presence of cells are highly nonlinear and often investigated through trial and error, leading to significant time and material costs. This paper proposes an approach based on artificial intelligence-assisted simulation, focusing on computer modeling of the biomechanical and functional parameters of hydrogel–cell composites produced by 3D bioprinting. The methodology is based on data generated from computer simulations and allows for analysis of the impact of printing parameters and different cross-linking strategies on mechanical strength, time-dependent geometric stability, and limitations related to cellular function, including exposure time to non-cross-linked matrices. The use of artificial intelligence methods allows for the integration of simulation results and predictive assessment of material behavior, providing a basis for future optimization of bioprinting parameters and process costs prior to experimental validation. Full article

(This article belongs to the Special Issue Design and Process Strategies for Mechanical Reinforcement in Polymer Additive Manufacturing)

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15 pages, 16547 KB

Open AccessEditor’s ChoiceArticle

Innovative Mycelium Bio-Composites (MB) from Birch Sanding Dust and Chitosan with Enhanced Heavy Metals Sorption Properties

by Oskars Bikovens, Anrijs Verovkins and Ilze Irbe

Materials 2026, 19(8), 1629; https://doi.org/10.3390/ma19081629 - 18 Apr 2026

Viewed by 1369

Abstract

Chitosan is a well-known heavy metal biosorbent and was incorporated into birch sanding dust mycelium bio-composites (MBs). The chitosan-hybridized MBs with different chitosan contents were characterized by microscopy, porous structure analyses (specific surface area and total pore volume), pH_pzc, functional group [...] Read more.

Chitosan is a well-known heavy metal biosorbent and was incorporated into birch sanding dust mycelium bio-composites (MBs). The chitosan-hybridized MBs with different chitosan contents were characterized by microscopy, porous structure analyses (specific surface area and total pore volume), pH_pzc, functional group content, and FTIR. Microscopy did not reveal any antifungal effect of chitosan on Trametes versicolor. The porous structure of the MBs decreased after hybridization with chitosan. The FTIR spectra and functional group analyses confirmed the presence of chitosan amino groups in the MBs. The chitosan-hybridized MBs were subjected to the adsorption of heavy metals, namely Cu(II) and Cd(II), and the removal percentage and adsorption isotherms were evaluated. Adsorption isotherms were analyzed using the Freundlich and Langmuir models. The results showed a significant increase in the maximum monolayer adsorption capacity for Cu(II), calculated using the Langmuir equation, from <2 mg/g for raw BSD and basic MB without chitosan to 19 mg/g for the MB with 15% chitosan. In the case of Cd(II), no significant increase in adsorption capacity was observed. These findings indicate that hybridization of MBs with chitosan is a promising approach to improve the Cu(II) adsorption capacity of MBs. Full article

(This article belongs to the Special Issue Sustainable and Functional Materials: From Design to Applications)

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21 pages, 9132 KB

Open AccessEditor’s ChoiceArticle

PLA Biocomposites Reinforced with Cinnamon-Treated Flax Fibers

by Magdalena Stepczyńska, Alona Pawłowska and Rafał Malinowski

Materials 2026, 19(8), 1632; https://doi.org/10.3390/ma19081632 - 18 Apr 2026

Viewed by 704

Abstract

In this research, PLA biocomposites reinforced with 20 wt% flax fibers modified with 1, 5, 10, and 20% concentrations of trans-cinnamic acid (TC) were prepared. The materials were systematically characterized to evaluate their structural, thermal, viscoelastic, surface, and functional properties. Thermal stability and [...] Read more.

In this research, PLA biocomposites reinforced with 20 wt% flax fibers modified with 1, 5, 10, and 20% concentrations of trans-cinnamic acid (TC) were prepared. The materials were systematically characterized to evaluate their structural, thermal, viscoelastic, surface, and functional properties. Thermal stability and phase transitions were analyzed using thermogravimetric analysis (TG) and differential scanning calorimetry (DSC), while viscoelastic behavior and molecular relaxation processes were investigated by dynamic mechanical analysis (DMA). To elucidate failure mechanisms and interfacial quality, fracture surface morphology after tensile testing was observed using scanning electron microscopy (SEM). Surface wettability was determined through water contact angle measurements, and antibacterial activity against Escherichia coli and Staphylococcus aureus was evaluated to assess the functional potential of the developed biocomposites. The results demonstrated that moderate fiber modification improved interfacial adhesion and enhanced thermo-mechanical performance. The highest contact angles were observed for 5% and 10% TC concentrations, indicating increased surface hydrophobicity, while strong antibacterial activity (R ≥ 6) was achieved for 10% and 20% TC. The research confirms that trans-cinnamic acid concentration governs multiple structure–property relationships, enabling controlled tuning of mechanical reinforcement and antibacterial functionality. Full article

(This article belongs to the Special Issue Advances in Biomass-Derived and Biodegradable Polymer Materials: Synthesis and Application)

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26 pages, 4044 KB

Open AccessEditor’s ChoiceReview

Ga-Based Liquid Metals: Advances in Interface Thermal and Electrical Regulations for Power Electronics Integration

by Canyu Liu, Tianqi Liu, Zhiwei Huang, Xiangyi Li, Jiabao Zheng, Guoxi Li, Gan Wang, Wentao Liu and Changqing Liu

Materials 2026, 19(8), 1599; https://doi.org/10.3390/ma19081599 - 16 Apr 2026

Viewed by 1091

Abstract

Ga-based liquid metals (GLMs) have been considered as promising thermal and electrical interface materials for advanced power electronics, combining high thermal conductivity (some types even >30 W/m·K) with fluidity at room temperature. This review systematically evaluates the dual roles of GLMs in power [...] Read more.

Ga-based liquid metals (GLMs) have been considered as promising thermal and electrical interface materials for advanced power electronics, combining high thermal conductivity (some types even >30 W/m·K) with fluidity at room temperature. This review systematically evaluates the dual roles of GLMs in power electronics packaging. Their function in thermal management as both thermal interface materials and active cooling media is first examined, followed by an analysis of their capabilities in forming electrical interconnections via low-temperature bonding in fluidic and solid states. However, reliable integration remains challenging due to interfacial reactions and instability with metal substrates. We discuss interfacial mechanisms with Cu and common metallizations, along with emerging regulation strategies such as surface coatings and process acceleration techniques. By examining these interfacial interactions, this work aims to guide the selection and design of surface modification strategies to either promote or inhibit reactions as needed, supporting the development of robust power electronic packaging. Full article

(This article belongs to the Special Issue Research Advances in Microelectronics Packaging and Devices: From Materials to Reliability)

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