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Coatings, Volume 15, Issue 5 (May 2025) – 109 articles

Cover Story (view full-size image): Graphene’s incorporation into epoxy coatings raises concerns regarding the galvanic corrosion of metallic substrates due to its high electrical conductivity. In this study, we explore the galvanic corrosion risk of mild steel coated with graphene-embedded epoxy using AC-DC-AC accelerated aging, which simulates real-world delamination by promoting interfacial degradation and ionic transport. Our results showed the minimal risk of cathodic reactions shifting to dispersed graphene within the epoxy matrix, confirming its limited role in galvanic corrosion. While graphene enhanced structural integrity, it weakened adhesion at the steel interface, making the system more prone to delamination. These findings are critical for designing more effective graphene-based coatings, balancing protection and adhesion stability. View this paper
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16 pages, 1604 KiB  
Article
Effect of Desulfurization Ash Content on the Low-Temperature Rheological Properties of Asphalt Mastic
by Yinghui Zhang, Kai Li, Yong Wu and Zhigang Zhou
Coatings 2025, 15(5), 604; https://doi.org/10.3390/coatings15050604 (registering DOI) - 18 May 2025
Abstract
Circulating fluidized bed combustion flue gas desulfurization generates large volumes of dry desulfurization ash requiring sustainable management. This study evaluated the impacts of substituting desulfurization ash for mineral powder filler in asphalt mastic on low-temperature rheological properties. Asphalt mastics were produced with 0–100% [...] Read more.
Circulating fluidized bed combustion flue gas desulfurization generates large volumes of dry desulfurization ash requiring sustainable management. This study evaluated the impacts of substituting desulfurization ash for mineral powder filler in asphalt mastic on low-temperature rheological properties. Asphalt mastics were produced with 0–100% ash replacing mineral powder at 0.8–1.2 powder-binder mass ratios. Ductility and bending beam rheometer testing assessed flexibility and crack resistance. Burgers’ model fitted bending creep compliance to derive relaxation time, m(t)/S(t) index, and low-temperature compliance parameter for analytical insight. Scanning electron microscopy and Fourier transform infrared spectroscopy probed microstructural development and interaction mechanisms. Results showed that the inclusion of desulfurization ash reduced the low-temperature performance of the asphalt mastic compared to the mineral powder asphalt mastic. Additionally, as the temperature decreased further, the effect of the powder-to-gum ratio on the slurry’s crack resistance became less pronounced. Desulfurization ash primarily interacted with the base bitumen through physical means, and the performance of desulfurization ash asphalt slurry mainly depended on the degree of swelling between the desulfurization ash and the base asphalt. Full article
(This article belongs to the Special Issue Novel Cleaner Materials for Pavements)
14 pages, 3346 KiB  
Article
Thin Films of PNDI(2HD)2T and PCPDTBT Polymers Deposited Using the Spin Coater Technique for Use in Solar Cells
by Michał Sładek, Patryk Radek, Magdalena Monika Szindler and Marek Szindler
Coatings 2025, 15(5), 603; https://doi.org/10.3390/coatings15050603 (registering DOI) - 18 May 2025
Abstract
Conductive polymers play a crucial role in the advancement of modern technologies, particularly in the field of organic photovoltaics (OPVs). Due to advantages such as flexibility, low specific weight, ease of processing, and low production costs, polymeric materials present an attractive alternative to [...] Read more.
Conductive polymers play a crucial role in the advancement of modern technologies, particularly in the field of organic photovoltaics (OPVs). Due to advantages such as flexibility, low specific weight, ease of processing, and low production costs, polymeric materials present an attractive alternative to traditional photovoltaic materials. This study investigates the properties of a polymer blend composed of PCPDTBT (donor) and PNDI(2HD)2T (acceptor), used as the active layer in bulk heterojunction (BHJ) solar cells. The motivation behind this research was the search for a novel n-type polymer material with potentially better properties than the commonly used P(NDI2OD-T2). Comprehensive characterization of thin films made from the individual polymers and their blend was conducted using Fourier Transform Infrared Spectroscopy (FTIR), Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), Ultraviolet-Visible Spectroscopy (UV-Vis), four-point probe conductivity measurements, and photovoltaic testing. The prepared films were continuous, uniform, and exhibited low surface roughness (Ra < 2.5 nm). Spectroscopic analysis showed that the blend absorbs light in a broad range of the spectrum, with slight bathochromic shifts compared to individual polymers. Electrical measurements indicated that the blend’s conductivity (9.1 µS/cm) was lower than that of pure PCPDTBT but higher than that of PNDI(2HD)2T, with an optical band gap of 1.34 eV. Photovoltaic devices fabricated using the blend demonstrated an average power conversion efficiency (PCE) of 6.45%, with a short-circuit current of 14.37 mA/cm² and an open-circuit voltage of 0.89 V. These results confirm the feasibility of using PCPDTBT:PNDI(2HD)2T blends as active layers in BHJ solar cells and provide a promising direction for further optimization in terms of polymer ratio and processing conditions. Full article
(This article belongs to the Special Issue Recent Developments in Thin Films for Technological Applications)
16 pages, 20780 KiB  
Article
Effect of Si on Mechanical Properties and Oxide Film Formation of AFA Alloy at Low Oxygen Pressure
by Qijun Jia, Xiaoqiang Jiang, Changjun Wu, Junxiu Chen, Xiangying Zhu, Ya Liu and Xuping Su
Coatings 2025, 15(5), 602; https://doi.org/10.3390/coatings15050602 (registering DOI) - 18 May 2025
Abstract
The Cr2O3 film on the outer surface of traditional cracking furnace tubes is prone to spalling, which shortens the tube life. Fe-Ni-Cr-based austenitic stainless steel (AFA alloy) with added Al has attracted attention because it can form a more stable [...] Read more.
The Cr2O3 film on the outer surface of traditional cracking furnace tubes is prone to spalling, which shortens the tube life. Fe-Ni-Cr-based austenitic stainless steel (AFA alloy) with added Al has attracted attention because it can form a more stable Al2O3 film on the surface. However, the alloy’s mechanical performance and the stability and oxidation resistance of the oxide film need to be improved simultaneously. This investigation examined silicon concentration variations (0–1.5 wt.%) on AFA alloy’s ambient-temperature tensile performance and oxidation response under reduced oxygen partial pressures (10−18–10−16 bar). The findings demonstrate that the alloy was composed of the FCC, B2-NiAl, and M23C6 phases. With Si addition, the B2-NiAl phase volume fraction increased. Mechanical testing demonstrated progressive elevation in tensile strength and hardness coupled with reduced elongation, attributable to combined solid-solution hardening and B2-NiAl precipitation strengthening. At low oxygen pressure, a continuous multi-layer oxide film developed on the alloy’s surface: the outermost layer was composed of a continuous Cr2O3 layer, with a fraction of MnCr2O4 spinel phase enriched on the outer surface. The middle layer was SiO2, which evolved from a particulate to a continuous layer with increasing Si content. The innermost layer was composed of Al2O3. Accelerated manganese diffusion through Cr2O3 facilitated MnCr2O4 spinel layer formation. Full article
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9 pages, 1798 KiB  
Article
Magnetoplasmonic Resonators Designed with Hexagonally Arrayed Au/BIG Bilayer Nanodisks on Au Thin Film Layers for Enhanced MOKE and Refractive Index Sensing
by Ziqi Wang, Xiaojian Cui and Yujun Song
Coatings 2025, 15(5), 601; https://doi.org/10.3390/coatings15050601 (registering DOI) - 18 May 2025
Abstract
A kind of magnetoplasmonic resonators is numerically designed with hexagonally arrayed Au/bismuth iron garnet (BIG) bilayer nanodiscks on Au thin film layers. Multi-physics coupling calculation on their magnetoplasmonic resonance features suggest that there exists a strong resonant coupling between the surface plasmon excited [...] Read more.
A kind of magnetoplasmonic resonators is numerically designed with hexagonally arrayed Au/bismuth iron garnet (BIG) bilayer nanodiscks on Au thin film layers. Multi-physics coupling calculation on their magnetoplasmonic resonance features suggest that there exists a strong resonant coupling between the surface plasmon excited by the hexagonal grating and the waveguide modes induced by Au-BIG-Au, which can significantly enhance the transverse magneto-optical Kerr effect. Interestingly, a new type of circular oscillating can be induced in the optical-transparent BIG layers as the thickness of BIG layers is between 2 nm and 22 nm. This circular oscillating exhibits a distinct thickness-dependent feature, which can be attributed to the near field interference of the excited localized plasmon resonance between the two interfaces formed by the middle BIG nanodiscs in the top Au nanodisks and the bottom Au thin film layers according to the simulation. These unique magnetoplasmonic features endow this kind of magnetoplasmonic resonators with a greatly enhanced refractive index sensing property, with a calculated figure of merit (FOM) value of up to 7527 RIU−1. Full article
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11 pages, 9609 KiB  
Article
Research on the Influence of Laser Cleaning Parameters on the Removal Effectiveness of Al Metal Layers from Ceramic Substrate Surfaces
by Yuqin Li, Hangchao Wang, Weizhuo Hua, Hang Wang and Yuchang Qing
Coatings 2025, 15(5), 600; https://doi.org/10.3390/coatings15050600 (registering DOI) - 18 May 2025
Abstract
This study explores a novel method for removing Al metal coatings by using nanosecond pulsed lasers to clean Al metal layers from ceramic substrate surfaces. The impact of laser power and pulse width on the effectiveness of the removal of the Al metal [...] Read more.
This study explores a novel method for removing Al metal coatings by using nanosecond pulsed lasers to clean Al metal layers from ceramic substrate surfaces. The impact of laser power and pulse width on the effectiveness of the removal of the Al metal layer from the ceramic substrate was examined. The findings revealed that a laser with a power of 120 W, a pulse width of 200 ns, a frequency of 240 kHz, and a speed of 6000 mm/s could effectively remove the Al metal layer (50 μm) in a single laser cleaning cycle without causing damage to the ceramic substrate. The mechanism behind the removal of the Al metal layer from the ceramic substrate surface was also investigated. It was discovered that local high temperatures caused by laser irradiation and the difference in thermal expansion coefficients between the metal layer and the ceramic substrate both contribute to the removal of the Al metal layer during the laser cleaning process. This research provides an effective process for removing the Al metal layer. Full article
(This article belongs to the Special Issue Advanced Coating Material for Heritage Preservation, 2nd Edition)
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36 pages, 8297 KiB  
Review
Research Progress of the Coatings Fabricated onto Titanium and/or Titanium Alloy Surfaces in Biomaterials for Medical Applications for Anticorrosive Applications
by Qin Rao, Jinshuang Zhang, Yaqing Chen, Yujin Yang, Xu Chen, Donghao Liu, Ruilu Zhu, Ang Li, Yanping Lv and Shunli Zheng
Coatings 2025, 15(5), 599; https://doi.org/10.3390/coatings15050599 (registering DOI) - 17 May 2025
Abstract
Titanium (Ti) and its alloys have attracted more interest, as they are widely employed as biomaterials due to their great biocompatibility, excellent strength ratio, and lightweight. However, corrosion occurs slowly due to an electrochemical reaction once the Ti material has been placed in [...] Read more.
Titanium (Ti) and its alloys have attracted more interest, as they are widely employed as biomaterials due to their great biocompatibility, excellent strength ratio, and lightweight. However, corrosion occurs slowly due to an electrochemical reaction once the Ti material has been placed in the human body, contributing to infection and failure of implants in medical applications. Thus, the corrosion phenomenon has caused great concern in the biomedical field. It is desirable to make the surface modification to provide better corrosion resistance. The fabrication techniques of the coatings fabricated onto Ti and/or Ti alloy surfaces have been reported, including sol–gel, annealing, plasma spraying, plasma immersion ion implantation, physical vapor deposition, chemical vapor deposition, anodization, and micro-arc oxidation. This review first describes the corrosion types, including localized corrosion (both pitting and crevice corrosion), galvanic corrosion, selective leaching, stress corrosion cracking (SCC), corrosion fatigue (CF), and fretting corrosion. In the second part, the effects of corrosion on the human body were discussed, and the primary cause for clinical failure and allergies has been identified as the excessive release of poisonous and dangerous metal ions (Co, Ni, and Ti) from corroded implants into bodily fluids. The inclusion and exclusion criteria during the selection of literature are described in the third section. In the last section, we emphasized the current research progress of Ti alloy (particularly Ti6Al4V alloy) coatings in biomaterials for medical applications involving dental, orthopedic, and cardiovascular implants for anticorrosive applications. However, there are also several problems to explore and address in future studies, such as the release of excessive metal ions, etc. This review will draw attention to both researchers and clinicians, which could help to increase the coatings fabricated onto Ti and/or Ti alloy surfaces for anticorrosive applications in biomaterials for medical applications. Full article
(This article belongs to the Special Issue Innovative Coatings for Corrosion Protection of Alloy Surfaces)
14 pages, 2627 KiB  
Article
Effect of TiC Addition on Microstructure and Performances of Double Pulse Electrodeposited Ni-TiC Coatings
by Haijun Liu, Hui Wang and Fafeng Xia
Coatings 2025, 15(5), 598; https://doi.org/10.3390/coatings15050598 (registering DOI) - 17 May 2025
Abstract
Nickel–titanium carbide (Ni-TiC) coatings were synthesized on Q235 steel via double-pulse electrodeposition to enhance surface properties. The influence of TiC concentration on surface morphology, microstructure, and performance was systematically studied using SEM, TEM, XRD, microhardness testing, wear analysis, and electrochemical methods. At low [...] Read more.
Nickel–titanium carbide (Ni-TiC) coatings were synthesized on Q235 steel via double-pulse electrodeposition to enhance surface properties. The influence of TiC concentration on surface morphology, microstructure, and performance was systematically studied using SEM, TEM, XRD, microhardness testing, wear analysis, and electrochemical methods. At low TiC concentrations (2–4 g/L), the coatings exhibited typical cell-like morphology. At 8 g/L, the coating showed a dense structure, refined grains, and broad Ni diffraction peaks. TEM analysis revealed nickel and TiC grain sizes of 97.82 nm and 34.75 nm, respectively. The plating rate remained stable (~36.94 mg·cm⁻2·h⁻1), while surface roughness increased with TiC content. The 8 g/L TiC coating achieved the highest microhardness (743.13 HV), lowest wear loss (5.43%), and superior corrosion resistance, with a self-corrosion current density of 5.27 × 10⁻6 A·cm⁻2 and polarization resistance of 7705.62 Ω·cm2. These enhancements are attributed to uniform TiC dispersion and grain boundary pinning. Thus, 8 g/L TiC is optimal for fabricating Ni-TiC coatings with improved mechanical and electrochemical performance. This work demonstrates a practical strategy for developing high-performance Ni-based composite coatings via double-pulse electrodeposition. Full article
31 pages, 823 KiB  
Review
Traditional and Recent Alternatives for Controlling Bacterial Foodborne Pathogens in Fresh Horticultural Commodities—A Review
by Silvia Bautista-Baños, Zormy Nacary Correa-Pacheco, Rosa Isela Ventura-Aguilar, Patricia Landa-Salgado, Mónica Cortés-Higareda and Margarita de Lorena Ramos-García
Coatings 2025, 15(5), 597; https://doi.org/10.3390/coatings15050597 (registering DOI) - 17 May 2025
Abstract
Fresh horticultural products have proven to be an excellent source of minerals, vitamins, and functional compounds for human consumption, resulting in horticultural production evolving from a local to a worldwide condition. However, during their commercialization, there can be side effects, such as the [...] Read more.
Fresh horticultural products have proven to be an excellent source of minerals, vitamins, and functional compounds for human consumption, resulting in horticultural production evolving from a local to a worldwide condition. However, during their commercialization, there can be side effects, such as the risk of contamination of foodborne illness outbreaks caused largely by bacterial microorganisms. To reduce their incidence, there exist conventional strategies that include mainly chemical and physical methods. Some of them have already been adopted by the horticultural food industry, while others are still under investigation, such as biological control. In recent years, research about the development and application of coatings has increased. There is a growing trend to design and evaluate active formulations based on naturally and non-toxic occurring compounds with antimicrobial effects against foodborne pathogens including, among others, essential oils, plant extracts, organic acids, and chitosan. Furthermore, nanomaterial-based formulations have also been recently tested, resulting in excellent materials to control them. Nevertheless, it is paramount to assess the safety and risk of these materials associated with human consumption. In this review, the current situation of foodborne pathogens in fruit and vegetables, the traditional control methods, and the future development of coating formulations with new materials are reviewed. In addition, the overall action mechanisms of the antimicrobial coating components were briefly described. Full article
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17 pages, 3659 KiB  
Article
Tribological Performance of TiN–WS2 Soft–Hard Multifunctional Composite Coatings Deposited by Magnetron Sputtering
by Hu Qiao, Shengchao Zhu, Suixin Fan, Jiawei Kang, Peichao Tian, Jianxin Yang and Youqing Wang
Coatings 2025, 15(5), 596; https://doi.org/10.3390/coatings15050596 (registering DOI) - 17 May 2025
Abstract
Titanium nitride (TiN) is a widely used industrial hard coating material, known for its excellent hardness and chemical stability. However, its relatively high coefficient of friction (COF) often leads to interfacial heat accumulation and adhesive wear during service, limiting its applicability in high-temperature [...] Read more.
Titanium nitride (TiN) is a widely used industrial hard coating material, known for its excellent hardness and chemical stability. However, its relatively high coefficient of friction (COF) often leads to interfacial heat accumulation and adhesive wear during service, limiting its applicability in high-temperature tribological environments. To enhance its tribological performance, a TiN–WS2 soft–hard composite coating was fabricated on cemented carbide substrates using reactive co-sputtering magnetron deposition. By adjusting the sputtering parameters and target power ratio, a synergistic deposition of the hard (TiN) and lubricating (WS2) phases was achieved and compared with a pure TiN coating. The results revealed that the incorporation of WS2 significantly reduced the COF at both room temperature (25 °C) and an elevated temperature (200 °C), with the average values decreasing from 0.61 to 0.39 at 25 °C and from 0.53 to 0.36 at 200 °C. A white light interferometry analysis showed that the TiN–WS2 coating exhibited narrower wear tracks and less surface damage than TiN at elevated temperatures, demonstrating superior friction-reducing and wear-resistant capabilities. In terms of mechanical properties, the composite coating showed a reduction in the hardness, the reduced elastic modulus (Er), and the adhesion strength by 27.3%, 19.8%, and 9.5%, respectively, compared to pure TiN. These findings indicate that the introduction of a quantitatively controlled lubricating WS2 phase allows for a balance between nanoscale hardness and wear resistance, offering promising potential for engineering applications under complex working conditions. Full article
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16 pages, 4581 KiB  
Article
PLA-Based Green Antimicrobial and Flame-Retardant Biocomposites Reinforced with Sida hermaphrodita Fibers
by Sandra Bischof, Tea Bušac, Tomislav Ivanković, Sabine Rolland du Roscoat, Bratislav Lukic and Zorana Kovačević
Coatings 2025, 15(5), 595; https://doi.org/10.3390/coatings15050595 (registering DOI) - 17 May 2025
Abstract
Enhanced demand for the development of sustainable materials has generated significant research interest in products containing biomass-derived fibers, such as the fibers extracted from the energy crop Sida hermaphrodita (SH). Green chemicals and green methods, such as microwave treatment, have been used for [...] Read more.
Enhanced demand for the development of sustainable materials has generated significant research interest in products containing biomass-derived fibers, such as the fibers extracted from the energy crop Sida hermaphrodita (SH). Green chemicals and green methods, such as microwave treatment, have been used for the isolation of fibers from biomass waste. In this study, long extracted fibers were used as a reinforcement of the PLA matrix to give them high strength, which is required for high-performance biocomposites. To enable composite usage in automotive industry, several additives were applied to enhance their mechanical, thermal, and antimicrobial properties. Therefore, vegetable drying oil, montmorillonite nanoclay (MMT), and milled cork were used to improve their mechanical and thermal properties. Zinc oxide (ZnO) was applied to enhance the biocomposite’s antimicrobial properties, which were confirmed through significant bacterial reduction across all tested biocomposite variants, particularly in samples functionalized with ZnO, cork, and montmorillonite. Additionally, X-ray microtomography provided detailed insight into fiber dispersion and internal structural heterogeneity, which is crucial for evaluating mechanical performance and flame-retardant behavior. All characterization methods, including mechanical ones, lead to the conclusion that green and sustainable biocomposites based on PLA and Sida hermaphrodita fibers treated with antimicrobial (AM) and flame-retardant (FR) agents can be successfully applied for a wide variety of antimicrobial and flame-retardant products. Full article
(This article belongs to the Special Issue Engineered Coatings for a Sustainable Future)
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10 pages, 2206 KiB  
Article
Experimental Investigation of Lubrication Performance of Rhombic-Textured TiN-Coated Surfaces Under Lubricated Conditions
by Juan Chen, Jie Zhou, Binbin Ji, Liangcai Zeng, Yang Mao and Jun Wei
Coatings 2025, 15(5), 594; https://doi.org/10.3390/coatings15050594 (registering DOI) - 17 May 2025
Abstract
Surface texture and titanium nitride (TiN) coating have been established as effective methods for enhancing the tribological properties of mechanical friction pairs. This work aims to investigate the lubrication performance of rhombic-textured TiN-coated surfaces under oil-lubricated conditions using a pin-on-disk test mode. A [...] Read more.
Surface texture and titanium nitride (TiN) coating have been established as effective methods for enhancing the tribological properties of mechanical friction pairs. This work aims to investigate the lubrication performance of rhombic-textured TiN-coated surfaces under oil-lubricated conditions using a pin-on-disk test mode. A total of 17 sets of samples were designed, including a control sample (with no rhombic texture and no TiN coating), a TiN-coated sample and rhombic-textured TiN-coated samples. The rhombic surface texture was fabricated using the end surface of a brass bar. TiN coating deposited TiN on the textured surface. This study focuses on measuring and comparatively analyzing the lubrication load capacity, friction coefficient (COF) and binding force of TiN coatings/substrates in the pin-on-disk friction test mode. Compared with the bare control sample, a rhombic texture can enhance lubrication load-carrying capacity by generating hydrodynamic lubrication effects, thereby reducing friction. Additionally, a rhombic texture enables the mitigation of third-body wear due to wear debris. This research provides valuable insights into the design and fabrication of mechanical friction pairs with high wear resistance under oil-lubricated conditions. For lubrication property enhancement, the influence of groove depth was larger than that of the length of the rhombic side. Full article
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17 pages, 1518 KiB  
Article
Magnetite-Modified Asphalt Pavements in Wireless Power Transfer: Enhancing Efficiency and Minimizing Power Loss Through Material Optimization
by Xin Cui, Aimin Sha, Liqun Hu and Zhuangzhuang Liu
Coatings 2025, 15(5), 593; https://doi.org/10.3390/coatings15050593 - 16 May 2025
Abstract
Wireless power transfer (WPT) is recognized as a critical technology to advance carbon neutrality in transportation by alleviating charging challenges for electric vehicles and accelerating their adoption to replace fossil fuel. To ensure durability under traffic loads and harsh environments while avoiding vehicle [...] Read more.
Wireless power transfer (WPT) is recognized as a critical technology to advance carbon neutrality in transportation by alleviating charging challenges for electric vehicles and accelerating their adoption to replace fossil fuel. To ensure durability under traffic loads and harsh environments while avoiding vehicle obstructions, WPT primary circuits should be embedded within pavement structures rather than surface-mounted. This study systematically investigated the optimization of magnetite-modified asphalt material composition and thickness for enhancing electromagnetic coupling in WPT systems through integrated numerical and experimental approaches. A 3D finite element model (FEM) and a WPT platform with primary-side inductor–capacitor–capacitor (LCC) and secondary-side series (S) compensation were developed to assess the electromagnetic performance of magnetite content ranging from 0 to 25% and pavement thickness ranging from 30 to 70 mm. Results indicate that magnetite incorporation increased efficiency from 80.3 to 84.7% and coupling coefficients from 0.236 to 0.242, with power loss increasing by only 0.25 W. This enhancement is driven by improved equivalent permeability, which directly enhances magnetic coupling efficiency. A critical pavement thickness of 50 mm was identified, beyond which the reduction in transmission efficiency increased significantly due to magnetic flux dispersion. Additionally, the nonlinear increase in power loss is partially attributed to the significant rise in hysteresis and eddy current losses at elevated magnetite content levels. The proposed design framework, which focuses on 10% magnetite content and a total pavement thickness of 50 mm, achieves an optimal energy transfer efficiency. This approach contributes to sustainable infrastructure development for wireless charging applications. Full article
(This article belongs to the Special Issue Synthesis and Application of Functional Polymer Coatings)
31 pages, 1018 KiB  
Review
Modern Innovations and Applications in Plasma Electrolytic Oxidation Coatings on Aluminum, Magnesium, and Titanium
by Angus G. McCarroll and Pradeep L. Menezes
Coatings 2025, 15(5), 592; https://doi.org/10.3390/coatings15050592 - 16 May 2025
Abstract
Plasma electrolytic oxidation (PEO) is an electrochemical surface modification technique for producing dense oxide layers on valve metals. This review compiles the various modifications to the PEO process that have been used to improve the produced coatings and make them suitable for specific [...] Read more.
Plasma electrolytic oxidation (PEO) is an electrochemical surface modification technique for producing dense oxide layers on valve metals. This review compiles the various modifications to the PEO process that have been used to improve the produced coatings and make them suitable for specific applications, with a focus on examples of aluminum, magnesium, and titanium substrates. An overview of the PEO process is given, highlighting the various process parameters and their effects on the final surface. The challenges with light metals that motivate the use of surface modifications are summarized, along with some of the other modifications that attempt to overcome them. Two broad categories of modifications to the PEO process are presented: in situ modifications, influencing the properties of the coating during its formation, and ex situ modifications, augmenting the properties of an already-formed coating. Finally, specific examples of applications for modified PEO processes are discussed, including battery, biomedical, water treatment, and energy production applications. Full article
16 pages, 3780 KiB  
Article
The Properties of Self-Compacting Ultra-High Performance Concrete with Different Types of Mineral Admixtures
by Lin Wang, Xiying Tian, Yuefan Pan, Dingyuan Wu, Shengli Xu, Hangyang Wang, Xiaolu Tian, Yubo Xu, Hong Guo and Min Zou
Coatings 2025, 15(5), 591; https://doi.org/10.3390/coatings15050591 - 16 May 2025
Abstract
This paper investigates the effects of silica fume, cenosphere, fly ash, and ground slag powder on the rheological properties and mechanical strengths of self-compacting ultra-high performance concrete (UHPC). The mass ratio of each mineral admixture varies from 0% to 15%, while the water-binder [...] Read more.
This paper investigates the effects of silica fume, cenosphere, fly ash, and ground slag powder on the rheological properties and mechanical strengths of self-compacting ultra-high performance concrete (UHPC). The mass ratio of each mineral admixture varies from 0% to 15%, while the water-binder ratios are set at 0.18, 0.20, and 0.22. The slump flow and plastic viscosity of fresh UHPC are measured, and the corresponding flexural and compressive strengths of UHPC cured for 3 days and 28 days are determined. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) are employed to elucidate the mechanisms underlying the observed performance changes. The results indicate that the addition of silica fume and mineral powder negatively impacts the fluidity of fresh UHPC but positively affects its plastic viscosity. Conversely, the inclusion of cenosphere and fly ash enhances the fluidity of fresh UHPC while having the opposite effect on its plastic viscosity. Increasing the water-binder ratio improves the fluidity of fresh UHPC but reduces its plastic viscosity. Mechanically, silica fume enhances the strengths of UHPC. In contrast, the cenosphere, fly ash, and mineral powder decrease the strengths of UHPC cured for 3 days but increase those cured for 28 days. UHPC containing silica fume exhibits the most compact hydration products and the lowest content of Ca(OH)2. Full article
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15 pages, 10425 KiB  
Article
The Effects of CeO2 Content on the Microstructure and Property of Duplex Stainless Steel Layer Obtained by Plasma Arc Cladding Technology
by Juan Pu, Di Wu, Xiaohui Shi, Fei Long and Huawei Sun
Coatings 2025, 15(5), 590; https://doi.org/10.3390/coatings15050590 - 16 May 2025
Abstract
The mixture powders were designed by adding 0 wt.%~1.0 wt.% CeO2 into the 2205 duplex stainless steel (DSS) powders. The 2205 DSS cladding layer was prepared on the surface of Q345 steel by plasma arc cladding technology. The effects of different CeO [...] Read more.
The mixture powders were designed by adding 0 wt.%~1.0 wt.% CeO2 into the 2205 duplex stainless steel (DSS) powders. The 2205 DSS cladding layer was prepared on the surface of Q345 steel by plasma arc cladding technology. The effects of different CeO2 contents on the macro-morphology, microstructure composition, and corrosion resistance of the cladding layer were studied. The action mechanism of CeO2 in the cladding layer was also discussed. The results showed that the addition of CeO2 modified the appearance and decreased the defect of the cladding layer. Also, the austenite grains were refined, and the austenite proportion was increased under the action of CeO2. When the CeO2 content was 0.5 wt.%, the appearance of the cladding layer was optimum; the austenite proportion in the upper cladding layer and the lower cladding layer reached up to 52.6% and 55.5%, respectively, and the crystal changed from columnar to equiaxed. CeO2 decomposes into Ce element and O element under the action of the plasma arc, after which Ce element is easily absorbed at the grain boundary to reduce the surface tension and improve the fluidity of the liquid metal so as to modify the appearance of the cladding layer. Meanwhile, Ce element primarily reacts with O, S, Al, and Si elements to form low-melting-point oxygen sulfides and are then removed, which eliminates the defect of the cladding layer. Moreover, the high melting point of CeO2 acts as heterogeneous nucleation sites during solidification, thus improving the value of nucleation rate/growth rate of the grain and promoting the transformation from ferrite to austenite. According to the electrochemical corrosion testing result, Ce element inhibited the enrichment of Cr element at grain boundaries and promoted the formation of Cr2O3, which improved the corrosion resistance of the 2205 DSS cladding layer. It was optimum with the CeO2 content of 0.5 wt.%. Full article
(This article belongs to the Special Issue Laser Surface Engineering and Additive Manufacturing)
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16 pages, 18412 KiB  
Article
Research on the Influence of Surface Defects Under the Influence of Rail Corrosion on the Fatigue Damage of Wheel Rolling Contact
by Longzhi Zhao, Minghui Mou, Daoyun Chen and Minshi Zhong
Coatings 2025, 15(5), 589; https://doi.org/10.3390/coatings15050589 - 15 May 2025
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Abstract
Heavy rolling contact fatigue (RCF) may be caused by wheel surface defects under the influence of rail corrosion, which threatens the operational safety of rail vehicles. To investigate the role of surface defects on wheel RCF damage under the influence of rail corrosion, [...] Read more.
Heavy rolling contact fatigue (RCF) may be caused by wheel surface defects under the influence of rail corrosion, which threatens the operational safety of rail vehicles. To investigate the role of surface defects on wheel RCF damage under the influence of rail corrosion, a salt spray tester was used to corrode the rails, an impact testing machine was employed to create surface defects, and RCF tests were completed. The role of surface defects on wheel RCF damage was studied by monitoring the wheel defect surface and cross-section. The results indicate that the tendencies of the RCF crack extension of surface defects of different sizes are similar, and they all extend in a C-shape along the tangential force direction. However, the larger the defect size, the later the crack is initiated. The leading edge material is continuously squeezed into the defect by the tangential force, and a larger plastic deformation layer is formed, which causes the RCF at the leading edge to crack more severely. Meanwhile, under the effect of combined normal force and shear stress, the leading edge crack intersects with the middle edge crack, and the leading edge material is spalled off first. Wheel RCF damage and wear are aggravated by rail corrosion, the longer the corrosion time, the more serious the RCF damage and wear, and the earlier the material spalling time, the lower the fatigue life. Full article
(This article belongs to the Special Issue Advancements in Surface Engineering, Coatings and Tribology)
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14 pages, 5738 KiB  
Article
Fluoro-Silicon-Modified Polythiourethane Copolymer for Marine Antifouling Coatings
by Songbo Xie, Xiufen Liao, Yanye Fan, Jiacheng Li, Qiumei Jiang, Yihua Zheng, Zhimin Huang and Shella Li
Coatings 2025, 15(5), 588; https://doi.org/10.3390/coatings15050588 - 15 May 2025
Viewed by 75
Abstract
Traditional marine antifouling coatings function through releasing toxic antifouling agents, causing serious harm to marine ecosystems. To address this challenge, an eco-friendly fluoro-silicon-modified polythiourethane (FSi-PTU) coating has been prepared via a polymerization reaction with dihydroxy propyl silicone oil (HO-PDMS-OH), 1H,1H,2H,2H-perfluorohexanol (FTOH), hexamethylene diisocyanate [...] Read more.
Traditional marine antifouling coatings function through releasing toxic antifouling agents, causing serious harm to marine ecosystems. To address this challenge, an eco-friendly fluoro-silicon-modified polythiourethane (FSi-PTU) coating has been prepared via a polymerization reaction with dihydroxy propyl silicone oil (HO-PDMS-OH), 1H,1H,2H,2H-perfluorohexanol (FTOH), hexamethylene diisocyanate (HDI), and pentaerythritol tetrakis (3-mercaptopropionate) (PETMP). The FSi-PTU polymer incorporates siloxane segments and fluorinated side chains, which are inhomogeneously distributed on the coating surface and construct a hydrophobic surface. The FSi-PTU coating exhibits good hydrophobicity, strong adhesion (≥2.14 MPa), and improved mechanical properties. The antifouling properties of the FSi-PTU coating have been researched. The results of laboratory tests demonstrate that the FSi-PTU coating exhibits excellent anti-protein adsorption and anti-algal attachment performance. The FSi-PTU-2 coating shows certain antifouling properties in the actual seawater test for three months. The results provide a certain reference value for developing eco-friendly marine antifouling coatings. Full article
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17 pages, 15972 KiB  
Article
Structure and Properties of Silver-Platinum-Titanium Dioxide Nanocomposite Coating
by Andrzej Dziedzic, Dariusz Augustowski, Paweł Kwaśnicki, Stanisław Adamiak, Wojciech Bochnowski, Anna Żaczek, Patrycja Skała, Bogumił Cieniek, Piotr Potera, Jakub Dziedzic, Małgorzata Kus-Liskiewicz and Dariusz Płoch
Coatings 2025, 15(5), 587; https://doi.org/10.3390/coatings15050587 - 15 May 2025
Viewed by 71
Abstract
The aim of this study was to produce a coating for protective glass glued to touch displays with high antibacterial effectiveness. This paper presents the structural, mechanical, optical, and antibacterial properties of a TiO2:Ag–Pt coating prepared by dual reactive DC and [...] Read more.
The aim of this study was to produce a coating for protective glass glued to touch displays with high antibacterial effectiveness. This paper presents the structural, mechanical, optical, and antibacterial properties of a TiO2:Ag–Pt coating prepared by dual reactive DC and RF magnetron sputtering. Characterization techniques used include XRD, TEM with EDS, SEM, AFM, nanoindentation for hardness and Young’s modulus, wettability tests, and optical property analysis. The coating exhibited columnar crystals with a width of 30–50 nm. Crystals of anatase, rutile, silver, and platinum with a size of up to 3 nm were identified. The coating deposited on glass had a concentration of 5.0 ± 0.2% at. Ag and 4.4 ± 0.1% at. Pt. The value of the optical band gap energy, corresponding to the direct transition, was 3.36 eV, while Urbach’s energy was in the order of 500 meV. The hydrophilic coating had a roughness RMS = 1.8 ± 0.2 nm, hardness HV = 6.8 ± 0.5 GPa, and Young’s modulus E = 116 ± 8 GPa. A unique combination of the phase composition of the TiO2:Ag–Pt coating, metallic Ag and Pt nanoparticles in a ceramic matrix of anatase and rutile crystallites resulted a >90% reduction of Staphylococcus aureus bacteria. This antibacterial effect was attributed to the activation of the doped semiconductor under visible light via plasmon resonance of the Ag and Pt nanoparticles, as well as a light-independent antibacterial action due to Ag+ ion release. In contrast, commercial antibacterial coatings typically achieve only around 60% bacterial reduction. Full article
(This article belongs to the Special Issue Optical Properties of Crystals and Thin Films, Volume II)
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12 pages, 2253 KiB  
Article
Interfacial Adsorption Mechanisms of Arginine, Glutamic Acid, Aspartic Acid, and Valine on Magnesium and Magnesium Alloy Surfaces: A First-Principles Investigation
by Zhe Fang, Shuaiwei Xu, Rui Cao, Mingli Jiao, Keyi Liu, Quan Diao, Shaokang Guan and Yu Jia
Coatings 2025, 15(5), 586; https://doi.org/10.3390/coatings15050586 - 15 May 2025
Viewed by 64
Abstract
Elucidating the interfacial interaction mechanisms between biomolecules and metal surfaces is crucial for designing functionalized biomedical materials. This study employs first-principles calculations based on density functional theory (DFT) to investigate the adsorption behaviors of arginine (Arg), glutamic acid (Glu), aspartic acid (Asp), and [...] Read more.
Elucidating the interfacial interaction mechanisms between biomolecules and metal surfaces is crucial for designing functionalized biomedical materials. This study employs first-principles calculations based on density functional theory (DFT) to investigate the adsorption behaviors of arginine (Arg), glutamic acid (Glu), aspartic acid (Asp), and valine (Val) on magnesium (Mg) and Mg alloy surfaces. The adsorption behaviors of four kinds of amino acids on Mg and Mg alloy surfaces were analyzed through optimized adsorption configurations, adsorption energies (Eads), bond lengths, projected densities of states (PDOSs), and differential charge densities. The calculated results of Eads followed the order of Arg > Glu > Asp > Val, driven by functional group spatial configurations and electron transfer efficiency. Alloying elements facilitated charge redistribution on the Mg and Mg alloy surfaces, enhancing the interaction between amino acids and the alloy surfaces. Notably, the guanidino group of Arg exhibited exceptional adsorption stability and multi-dentate bonding, increasing electron donation to the Mg(0001) surface, achieving the highest Eads (−1.67 eV). This work provides insights into the structure–activity relationships between amino acids and Mg and Mg alloy surfaces, offering a foundation for designing biomolecule-derived functional coatings and strategies for improving the biocompatibility of Mg and Mg alloy implants. Full article
(This article belongs to the Special Issue Advanced Alloy Degradation and Implants, 2nd Edition)
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16 pages, 6592 KiB  
Article
Hydrogen Embrittlement Resistance of Ferritic–Pearlitic Pipeline Steel with Non-Electrochemically Deposited Copper- or Nickel–Phosphorus-Based Coating
by Ladislav Falat, Lucia Čiripová, František Kromka, Viera Homolová, Róbert Džunda and Marcela Motýľová
Coatings 2025, 15(5), 585; https://doi.org/10.3390/coatings15050585 - 15 May 2025
Viewed by 70
Abstract
This work deals with the effects of a non-electrochemically deposited copper- or nickel–phosphorus-based coating on the resulting resistance of traditional X42 grade pipeline steel against hydrogen embrittlement (HE). The susceptibility to HE was determined by the evaluation of the hydrogen embrittlement index (HEI) [...] Read more.
This work deals with the effects of a non-electrochemically deposited copper- or nickel–phosphorus-based coating on the resulting resistance of traditional X42 grade pipeline steel against hydrogen embrittlement (HE). The susceptibility to HE was determined by the evaluation of the hydrogen embrittlement index (HEI) from the results of conventional room-temperature tensile tests using cylindrical tensile specimens. Altogether, three individual material systems were studied, namely uncoated steel (X42) and two coated steels, specifically with either a copper-based coating (X42_Cu) or a nickel–phosphorus-based coating (X42_Ni-P). The HEI values were calculated as relative changes in individual mechanical properties corresponding to the non-hydrogenated and electrochemically hydrogen-precharged tensile test conditions. Both applied coatings considerably improved the hydrogen embrittlement resistance of the investigated steel in terms of decreasing the HEI values related to the changes in the yield stress, ultimate tensile strength, and reduction of area. In contrast, the hydrogenation of both coated systems had detrimental effects on the value of total elongation, which resulted in an increase in the corresponding HEI value. This behavior was likely related to the earlier onset of necking during tensile straining due to strain localizations induced by the coatings’ surface imperfections. The findings from fractographic observations indicated that both studied coatings acted like protective barriers against hydrogen permeation. However, the surface quality in terms of pores and other superficial defects in the considered coatings remains a challenging issue. Full article
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23 pages, 6342 KiB  
Article
Nanostructured Coatings for Spinal Fixation Screws: A Dual-Function Approach Against Biofilm Formation and Implant Failure
by Tiberiu Gabriel Panaitescu, Adelina-Gabriela Niculescu, Valentina Grumezescu, Bogdan Costăchescu, Alexandra Cătălina Bircă, Paul Cătălin Balaure, Ovidiu Cristian Oprea, Ionela Cristina Voinea, Miruna S. Stan, Alina Maria Holban, Bogdan Ștefan Vasile, Alexandru Mihai Grumezescu and Daniel Mihai Teleanu
Coatings 2025, 15(5), 584; https://doi.org/10.3390/coatings15050584 - 14 May 2025
Viewed by 108
Abstract
Implant-associated infections represent challenging complications following orthopedic surgeries, with spinal fixation procedures being particularly linked with increased risks. Thus, urgent research is required to develop enhanced solutions to avoid bacterial colonization, associated implant failure, and severe issues. Our study is based on the [...] Read more.
Implant-associated infections represent challenging complications following orthopedic surgeries, with spinal fixation procedures being particularly linked with increased risks. Thus, urgent research is required to develop enhanced solutions to avoid bacterial colonization, associated implant failure, and severe issues. Our study is based on the laser coating of surfaces with a composite mixture of PLA/Fe3O4@CEF that can fight against infectious agents and preserve their activity for a prolonged time. In the present study, we synthesized Fe3O4@Ceftriaxone (CEF) nanoparticles by co-precipitation and blended them into polylactic acid (PLA)-based coatings that were thoroughly evaluated from physicochemical and biological points of view. The novelty of this work is the dual functionality of these coatings, combining localized, sustained antibiotic delivery with enhanced biocompatibility for spinal screw applications. The coatings exhibited substantial anti-biofilm effects, reducing Staphylococcus aureus colonization from 1.8 × 108 to 1.6 × 105 CFU/mL and Pseudomonas aeruginosa from 1.2 × 1011 to 1.9 × 106 CFU/mL after 24 h. Furthermore, in vitro assays with murine preosteoblasts and human osteoblasts demonstrated excellent biocompatibility, maintaining >95% cell viability and showing no significant cytotoxicity or inflammatory response. These results highlight the potential of PLA/Fe3O4@CEF composite coatings in preventing implant-associated infections and promoting osseointegration, offering a multifunctional strategy for improving spinal fixation screw longevity and patient outcomes. Full article
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17 pages, 1280 KiB  
Article
Effects of Polysaccharide-Based Edible Coatings on the Quality of Fresh-Cut Beetroot (Beta vulgaris L.) During Cold Storage
by Sabina Galus, Hanna Kowalska, Anna Ignaczak, Jolanta Kowalska, Magdalena Karwacka, Agnieszka Ciurzyńska and Monika Janowicz
Coatings 2025, 15(5), 583; https://doi.org/10.3390/coatings15050583 - 14 May 2025
Viewed by 129
Abstract
This study evaluated the effects of selected polysaccharide edible coatings (apple pectin and sodium alginate) on the quality characteristics of fresh-cut beetroot. The changes in texture (hardness), optical parameters such as colour and Hue angle, polyphenols, flavonoids, and red and yellow colourants during [...] Read more.
This study evaluated the effects of selected polysaccharide edible coatings (apple pectin and sodium alginate) on the quality characteristics of fresh-cut beetroot. The changes in texture (hardness), optical parameters such as colour and Hue angle, polyphenols, flavonoids, and red and yellow colourants during 4 weeks of refrigerated storage, as well as changes in microstructure, were examined. Self-standing coatings have also been prepared and characterised by continuous structure without pores, cracks, and high lightness. The obtained results for hardness showed reduced values during storage. Colour parameters (L*, a*, and b*) and Hue angle remained mostly consistent, indicating the preservation of the desired colour, though slight changes were noted during storage. Lightness (parameter L*) increased over time, suggesting changes in the beetroot surface. However, these changes were less pronounced in samples covered with coatings. The use of polysaccharide coatings and storage time positively impacted flavonoids in fresh-cut beetroots, except after 28 days when the lowest values for both parameters were observed. It can also be noted that the polyphenol content in coated samples decreased at a slower rate. Moreover, there was a significant decrease in the content of red and yellow colourants for both control and coated samples. However, greater changes were noted for samples treated with coatings. Scanning electron microscopy used at 0 and 28 days showed lower pores in beetroot tissue as a result of applied polysaccharide coatings, and refrigerated storage negatively affected the minimally processed beetroot surface. Nevertheless, minimally processed beetroots obtained with the treatment of polysaccharide coatings as mild technology showed modifications to the quality characteristics, which can find practical use in reducing the waste of fresh-cut vegetables during storage. Full article
(This article belongs to the Special Issue Biodegradable Films and Composite Coatings: Current and Future Trends)
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15 pages, 4920 KiB  
Article
Investigation on the Viscosity–Temperature Properties for Various EPDM Solutions Based on Three-Dimensional Solubility Parameters and Flory–Huggins Interaction Parameters
by Yuqing Yang, Yiran Jing and Guangyong Liu
Coatings 2025, 15(5), 582; https://doi.org/10.3390/coatings15050582 - 14 May 2025
Viewed by 118
Abstract
Three organic solvents, cyclohexane, n-hexane and n-heptane were selected to dissolve the Ethylene-Propylene-Diene Monomer (EPDM) to keep the mass fractions of EPDM solution at 5 wt% and 10 wt%, respectively. The viscosities of three EPDM solutions at different temperatures were measured by a [...] Read more.
Three organic solvents, cyclohexane, n-hexane and n-heptane were selected to dissolve the Ethylene-Propylene-Diene Monomer (EPDM) to keep the mass fractions of EPDM solution at 5 wt% and 10 wt%, respectively. The viscosities of three EPDM solutions at different temperatures were measured by a rotary viscometer. The experimental results show that the concentration and temperature exert significant influences on the viscosities of the EPDM solutions, compared with the rotor type and rotational speed having no obvious effect on the viscosities. An EPDM solution with higher concentration shows remarkable higher viscosity. The viscosities show almost linear decline with increasing temperature within the experimental temperature range, which is also called a viscosity–temperature curve. However, the temperature dependences of viscosity are varied for the three different EPDM solutions. The compatibility between EPDM and solvents could be characterized by the energy difference (Ra) and Flory–Huggins interaction parameter (χ), which has also been attempted to be correlated with the viscosity–temperature curve and solvent molar volume. It is found that the smaller Ra value relates to better compatibility of the EPDM solution and greater slope of the viscosity–temperature curve. Furthermore, the viscosity of EPDM solution and the slope of the viscosity–temperature curve are affected more significantly by the molar volume of solvent when the Ra value is similar. A formula for predicting the viscosity of EPDM solution has been established by using a new Flory–Huggins interaction parameter (χHSP), which can also be used to calculate the viscosity at the extreme temperature that is difficult to be measured. Finally, for the three EPDM solutions, the different dissolution temperatures corresponding to the same viscosity can be obtained by formula calculations with the achieved prediction formulas. Full article
(This article belongs to the Section Thin Films)
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17 pages, 6029 KiB  
Article
Optimization of Elliptical Double-Beta Spray Gun Model Under the Control of Fan Air Pressure
by Yajie Tan, Zhuo Wang, Zichao Zhang and Sundong Mo
Coatings 2025, 15(5), 581; https://doi.org/10.3390/coatings15050581 - 14 May 2025
Viewed by 119
Abstract
The air spray gun model for painting robots is a mathematical model that describes the performance and behavior of the air spray gun in a spray-painting system and simulates the spraying process. Currently, film uniformity and spraying efficiency are key factors in evaluating [...] Read more.
The air spray gun model for painting robots is a mathematical model that describes the performance and behavior of the air spray gun in a spray-painting system and simulates the spraying process. Currently, film uniformity and spraying efficiency are key factors in evaluating the spray performance of this model. To further enhance the accuracy and controllability of spray gun modeling, this study used the elliptical double-beta spray pattern model to investigate the key parameters influencing its performance. Fan air pressure was selected as the optimization variable. A fixed-point spraying experimental platform was established where spraying experiments were conducted under six different pressures, and coating thickness data were collected. The optimal fitting function was obtained using data processing software. Experimental verification showed that the amplitude error was within 3 mm and the film thickness error was within 4 µm. The results indicate that fan air pressure can accurately predict film thickness, significantly improving paint utilization, with a high engineering application value. This provides new theoretical support for precise control in the spraying process and optimization of automated spraying systems. Full article
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13 pages, 3405 KiB  
Article
First-Principles Investigation of the Structural, Magnetic, and Electronic Properties of Janus MXene Material CrScCO2
by Haishen Huang, Xiaoying Liu, Li Sun, Zhenzhen Shang, Tingyan Zhou, Ping Li and Bo Wu
Coatings 2025, 15(5), 580; https://doi.org/10.3390/coatings15050580 - 13 May 2025
Viewed by 171
Abstract
This study employed first-principles density functional theory (DFT) to systematically investigate the influence of oxygen (–O) functional groups on the structural, magnetic, and electronic properties of Janus MXene CrScC. Nine distinct CrScCO2 configurations with varying oxygen adsorption sites were examined. All configurations [...] Read more.
This study employed first-principles density functional theory (DFT) to systematically investigate the influence of oxygen (–O) functional groups on the structural, magnetic, and electronic properties of Janus MXene CrScC. Nine distinct CrScCO2 configurations with varying oxygen adsorption sites were examined. All configurations exhibited robust ferromagnetic ordering, with total magnetic moments ranging from 1 to 3 μB, predominantly contributed by Cr atoms. Notably, the majority of the configurations exhibited half-metallic behavior, characterized by fully spin-polarized conduction channels and half-metallic gaps spanning 0.23–1.54 eV, with one configuration approaching a spin-gapless semiconductor characterized by a minimal bandgap (<0.1 eV). The ground-state configuration demonstrated strong performance, featuring a 100% spin polarization ratio and a wide half-metallic gap of 0.44 eV, indicating significant potential for spintronic applications. Phonon spectrum calculations confirmed the dynamic stability of the half-metallic ground-state structure, while binding energy analysis highlighted the enhanced stability of the oxygen-functionalized system compared to pristine CrScC. These results demonstrate that –O functional groups play a key role in modulating the magnetism and electronic properties of CrScC, offering versatility for various spintronic device applications. Full article
(This article belongs to the Special Issue Design of Nanostructures for Energy and Environmental Applications)
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11 pages, 2127 KiB  
Article
Characterization of Boride Layers on S235 Steel and Calculation of Activation Energy Using Taylor Expansion Model
by Mourad Keddam, Peter Orihel, Peter Jurci and Martin Kusy
Coatings 2025, 15(5), 579; https://doi.org/10.3390/coatings15050579 - 13 May 2025
Viewed by 108
Abstract
S235 low-carbon steel was boronized between 1123 K and 1273 K using a commercial powder mixture (Durborid) to study the formation and growth behavior of boride layers. The type of interface and thickness of the resulting layers were determined with scanning electron microscopy [...] Read more.
S235 low-carbon steel was boronized between 1123 K and 1273 K using a commercial powder mixture (Durborid) to study the formation and growth behavior of boride layers. The type of interface and thickness of the resulting layers were determined with scanning electron microscopy (SEM). The technique of X-ray diffraction (XRD) confirmed the formation of a predominantly single-phase Fe2B layer under most processing conditions. To assess the diffusion behavior, the kinetic model with a Taylor series expansion was implemented to calculate the B diffusion coefficients in the Fe2B layer under a transient diffusion regime. The B activation energy in Fe2B was determined to be 157 kJ/mol, which aligns well with values derived from the literature. Full article
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10 pages, 4047 KiB  
Article
Super-Hydrophobic Photothermal Copper Foam for Multi-Scenario Solar Desalination: Integrating Anti-Icing, Self-Cleaning, and Mechanical Durability
by Chen Shao, Guojian Yang, Kang Yuan and Liming Liu
Coatings 2025, 15(5), 578; https://doi.org/10.3390/coatings15050578 - 13 May 2025
Viewed by 159
Abstract
Solar desalination is widely regarded as an effective way to solve freshwater scarcity. However, the balance between the costs of micro-nanostructures, thermal regulation, and the durability of interface evaporators must all be considered. In this study, a super-hydrophobic copper foam with hierarchical micro-nanostructures [...] Read more.
Solar desalination is widely regarded as an effective way to solve freshwater scarcity. However, the balance between the costs of micro-nanostructures, thermal regulation, and the durability of interface evaporators must all be considered. In this study, a super-hydrophobic copper foam with hierarchical micro-nanostructures exhibited temperatures greater than 66 °C under solar illumination of 1 kW·m−2. Significantly, the modified copper foam acting as a solar interface evaporator had a water harvesting efficiency of 1.76 kg·m−2·h−1, resulting from its good photothermal conversion and porous skeleton. Further, the anti-deicing, self-cleaning, and anti-abrasion tests were carried out to demonstrate its durability. The whole fabrication of the as-prepared CF was only involved in mechanical extrusion and spray-coating, which is suitable for large-scale production. This work endows the interface evaporator with super-hydrophobicity, photo-thermal conversion, anti-icing, and mechanical stability, all of which are highly demanded in multi-scenario solar desalination. Full article
(This article belongs to the Special Issue Self-Cleaning and Anti-Fouling Coatings)
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17 pages, 6284 KiB  
Article
Study on the Energy Storage and Driving Performance of IPMC with Laminated Structure Electrodes
by Jintao Zhao, Yanqi Dong, Zhenjie Zhang, Dongyu Yang, Siyan Zhang and Mingchuan Jia
Coatings 2025, 15(5), 577; https://doi.org/10.3390/coatings15050577 - 13 May 2025
Viewed by 135
Abstract
Ionic polymer–metal composites (IPMC) have the advantages of a large driving mass ratio, low driving voltage, and high current sensitivity, but their low electrode continuity, low energy storage, and unclear driving response mechanisms limit further application and development. In this study, Nafion is [...] Read more.
Ionic polymer–metal composites (IPMC) have the advantages of a large driving mass ratio, low driving voltage, and high current sensitivity, but their low electrode continuity, low energy storage, and unclear driving response mechanisms limit further application and development. In this study, Nafion is used as the base film and metallic silver is used as the electrode material to modify IPMC electrodes. The physical and electrochemical properties of silver-based IPMC with three electrode preparation processes are tested, and the effects of different electrode preparation processes and structures on the energy storage performance and driving performance of IPMC are analyzed. The results show that the electrode coating effect of the Hot Press Chemical Plating method (HPCP) is good and maintains better continuity, and the formed layer electrode can improve the energy storage performance of IPMC, and the enhancement of energy storage performance can improve the driving performance of IPMC. This study enhances the energy storage performance and driving performance of IPMC from the perspective of electrode process and structure and provides a basis for the study of the enhancement of energy storage performance of IPMC by the HPCP electrode preparation process. Full article
(This article belongs to the Special Issue Cutting Performance of Coated Tools)
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22 pages, 13360 KiB  
Article
The Impact of the Antimicrobial Packaging Covered with Coatings Containing Carvacrol or Geraniol with the Addition of Zinc Oxide on the Quality of Sliced Plant-Based Sausages
by Małgorzata Mizielińska, Marcelina Tarnowska and Wojciech Jankowski
Coatings 2025, 15(5), 576; https://doi.org/10.3390/coatings15050576 - 12 May 2025
Viewed by 147
Abstract
The aim of this work was to estimate the impact of polypropylene (BOPP) films with active coatings applied on their surface on the quality of sliced, plant-based meat analogue (PBMA) sausages. The coatings contained zinc oxide nanoparticles and geraniol (AG) or zinc oxide [...] Read more.
The aim of this work was to estimate the impact of polypropylene (BOPP) films with active coatings applied on their surface on the quality of sliced, plant-based meat analogue (PBMA) sausages. The coatings contained zinc oxide nanoparticles and geraniol (AG) or zinc oxide and carvacrol (AC) as active compounds. The outcomes of the study indicated that the total microbial count of ready-to-eat, sliced PBMAs bought from a local store was high, confirming that the plant-based sausage must have been contaminated during slicing. It was shown that BOPP bags and spacers covered with the AG layer reduced the number of mesophilic bacteria in sliced plant-based sausages stored for 96 h, proving that this packaging material maintained the microbial quality of PBMA samples. It has to be underlined that neither S. aureus, L. monocytogenes, Salmonella sp. nor coliform bacteria were detected in the plant sausage samples after 48 h and 96 h of storage in the BOPP packaging covered with the AG and AC coatings, confirming that these slices were acceptable for consumption. However, the textural analysis showed that bags coated with the AC layer were the best bags for 96 h of storage. Full article
(This article belongs to the Special Issue Advanced Coatings and Films for Food Packing and Storage, 2nd Edition)
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12 pages, 6789 KiB  
Article
Effects of Rolling Strategies on Microstructure Uniformity of High-Purity Tantalum Plates
by Ziyi Zhu, Junfeng Luo, Jiali Gao, Haishuang Lv, Yuanyuan Jiang, Jianghao Bai and Jinjiang He
Coatings 2025, 15(5), 575; https://doi.org/10.3390/coatings15050575 - 12 May 2025
Viewed by 180
Abstract
High-purity tantalum plates form inhomogeneous microstructures and texture gradients along the thickness through conventional rolling, which seriously affects the sputtering performance of the target. In this work, tantalum plates with a random microstructure were used on different rolling paths, such as those in [...] Read more.
High-purity tantalum plates form inhomogeneous microstructures and texture gradients along the thickness through conventional rolling, which seriously affects the sputtering performance of the target. In this work, tantalum plates with a random microstructure were used on different rolling paths, such as those in unidirectional rolling (UR) and cross rolling (CR). The microstructure of the rolled tantalum plates was characterized using electron backscatter diffraction (EBSD), X-ray diffraction (XRD), and Vickers hardness (HV). The results indicated that the UR specimen exhibited the highest hardness values, with a gradual increase in hardness across the entire thickness layer from the surface to the center. Furthermore, specimens with different rolling directions demonstrated distinct texture gradient distributions throughout the thickness. The unidirectional rolling (UR) sample had a {110} (<110>//ND) texture on the surface and a {111} (<111>//ND) texture on the rest of its thickness. Compared with UR, cross rolling introduces more shear deformation, increases the content of the {100} (<100>//ND) texture, and weakens the {111} texture intensity everywhere except the center region. An increase in the rolling direction is beneficial for weakening the inhomogeneity between microstructures. Full article
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