Chemistry and Materials Science

Abstract: Silver (Ag)-based conductive coatings are widely used in electrical contacts due to their excellent electrical conductivity, low contact resistance, good thermal stability and oxidation resistance, although their susceptibility to sulfidation and environmental corrosion is a concern under certain service conditions. In recent years, significant progress has been achieved in both the manufacture and performance optimization of Ag-based coatings to satisfy the demanding requirements of modern electrical and electronic systems. This review summarizes recent advances in fabrication techniques and processing parameters for Ag-based coatings, including electroplating, electroless deposition, magnetron sputtering, electrospark deposition, thermal spraying, and electrical explosion spraying on metallic substrates, particularly on copper and steel substrates. More attention is given to microstructural design strategies, such as the incorporation and homogeneous dispersion of reinforcement or solid lubricant phases within the Ag matrix, to enhance contact reliability and operational endurance. The performance of Ag-based coatings is analyzed in terms of their physical, chemical and mechanical properties, electrical contact resistance, friction and wear behavior, arc erosion resistance, and environmental durability under different service conditions. Key challenges, including coating degradation under high electrical loads, mechanical wear, and corrosive environments, are highlighted. Future research directions are outlined, focusing on multifunctional coating structures that enhance surface performance and ensure the long-term durability of electrical contacts.

Abstract: To solve the drawbacks of conventional long-cycle wear tests for miniature standing- wave linear ultrasonic motors, an accelerated equivalent wear model and test system were proposed in this work. After primary screening of multiple friction pair materials, graphite and Al2O3 were adopted to modify epoxy films. The optimal friction pair is composed of 6061 hard anodic oxidation film and ECA105 composite film. The matched pair exhibits excellent driving stability and low wear loss, with fatigue wear as the main wear form. Graphite and Al₂O₃ exert synergistic anti-wear and load-bearing effects via forming a stable transfer film on the friction interface. Experimental results confirm that the accelerated test is equivalent to full-life durability test. The presented method and optimized friction pair can effectively guide the development of high-performance ultrasonic motors.

Abstract: Increasingly stringent fire safety, environmental, and occupational health regulations have accelerated the development of sustainable fire-resistant materials. WEICs have gained attention as multifunctional passive fire protection systems due to their strong substrate adhesion, low volatile organic compound emissions, and environmentally compatible formulations. This review highlights recent advances in epoxy-based intumescent composite coatings, focusing on how formulation design and microstructural characteristics influence fire-protective performance. Key flame-retardant mechanisms, including thermal degradation, chemical transformation, and char expansion behaviour, are discussed within heterogeneous composite systems. Emphasis is placed on the synergistic interactions among acid sources, carbon-forming agents, and blowing agents, as well as on incorporating fillers and reinforcing phases to enhance thermal insulation and expansion stability. Emerging strategies involving nanostructured reinforcements, bio-based additives, and hybrid composites are also evaluated for their potential to enhance char strength, mechanical durability, and heat resistance. Despite notable progress, challenges remain in long-term durability, interfacial compatibility, economic feasibility, and large-scale implementation, highlighting the need for halogen-free, low-toxicity intumescent coating technologies.

Abstract: Light-converting polymer coatings and films are emerging passive photonic materials for spectral engineering in sustainable and protected agriculture. By absorbing ultraviolet or weakly used spectral components and re-emitting in visible bands that overlap with photosynthetic pigments and plant photoreceptor action regions, these materials can modify the radiation environment without additional electrical energy input. This critical review analyses light-converting polymer films and coatings from a materials and coatings perspective, with emphasis on photophysical mechanisms, polymer matrices, luminophore families, coating fabrication routes, optical transparency, photoluminescence, aggregation phenomena, photostability and scalability. The photobiological background is included as a concise framework that justifies the spectral targets of the conversion process. Rare-earth complexes, inorganic phosphors, quantum dots, aggregation-induced-emission systems and organic dyes are compared as candidate luminophores. Particular attention is paid to an author-developed perylene diimide (PDI)-modified poly(methyl methacrylate) (PMMA) solution-cast coating system, used here as a representative case study to discuss dispersion, optical homogeneity and aggregation-related losses. Extrusion, solution casting, spin-coating, dip-coating and sol–gel processing are evaluated as fabrication strategies for laboratory and large-area greenhouse applications. The work concludes by identifying the main gaps that must be addressed before practical deployment: quantitative UV–Vis and photoluminescence characterization, absolute quantum yield, haze and scattering, thickness and morphology mapping, accelerated UV ageing, weathering resistance, toxicity assessment and crop-specific validation.

Abstract: Fifteen blue-and-white Chinese porcelain sherds dated from the seventeenth to nineteenth centuries, from Jingdezhen, Anxi, and Dehua kilns, were analysed and compared with fragments recovered from the Santana Convent in Lisbon. This work focuses on the identification of cobalt pigment sources, glaze technology and microstructural features for provenance assessment. Sherds were studied using several non-invasive spectroscopies, namely micro-Raman, X-Ray Photoelectron spectroscopy (XPS), X-Ray Fluorescence (XRF) and Ground State Diffuse Reflectance (GSDR). The mineralogical characterization of the ceramic bodies was performed with the use of the X-ray diffraction technique (XRD) and stereomicroscopy (SM). The GSDR absorption spectra of the dark blue and light blue glazes are in most cases quite different. These spectra, together with the XPS studies point to different forms of cobalt ions emplacement in the surface glassy structure of the glaze, or to the use of different pigments to obtain the dark or the light blues decoration of the porcelains. This study aims to clarify the provenance of the Santana Convent sherds (specially the 18th century ones). The multi-analytical characterization achieved in this study, points to the Dehua kilns as the most probable provenance for samples S11 and S12, of the Part [1] study.

Abstract: Membrane Distillation (MD) is a heat-driven seawater desalination technology that uses a hydrophobic microporous membrane as its core component. Due to its low energy consumption, high separation efficiency, and ability to handle high-concentration saline wastewater, it has become an effective solution to the shortage of freshwater resources. Neverless, issues such as membrane wetting, membrane fouling, and low membrane flux severely limit its large-scale application. Composite membranes prepared using metal-organic framework (MOF) materials as fillers have become a research hotspot due to their advantages, such as permeable microporous channels, customizable pore structures, and modifiable active sites. These properties enable them to effectively reduce temperature polarization and concentration polarization phenomena. This article describes the characteristics of metal-organic framework materials and their current applications in the field of membrane distillation. Comparative analysis of the applicability of MOF polycrystalline membranes and MOF composite membranes in membrane distillation. Discussed the working principle of MOFs in enhancing the performance of membrane distillation. Finally, the problems and challenges associated with the use of MOFs in membrane distillation applications were analyzed. Aims to provide theoretical guidance for the application of metal-organic framework materials in the field of membrane distillation seawater desalination.

Abstract: This manuscript evaluates the electrochemical corrosion resistance of diamond-like car-bon (DLC) coatings deposited via High-Power Impulse Magnetron Sputtering (HiPIMS) on AISI 52100 steel in synthetic seawater. While AISI 52100 steel is valued for its hardness, it is highly susceptible to localized and uniform corrosion in chloride-rich marine environ-ments. In this study, samples were characterized using Raman spectroscopy to analyze sp2/sp3 bonding, and their corrosion behavior was assessed through potentiodynamic po-larization, linear polarization resistance (LPR), and electrochemical impedance spectros-copy (EIS) over 24 hours of immersion. Results demonstrated that the DLC coatings signif-icantly enhanced electrochemical stability, shifting corrosion potentials toward more no-ble values and reducing corrosion current densities by several orders of magnitude com-pared to the uncoated substrate. EIS data revealed high polarization resistance and effec-tive barrier properties, despite a calculated total porosity of 3.06% resulting from intrinsic micro-defects. Although localized subsurface degradation and minor flaking were ob-served at defect sites, the HiPIMS-deposited DLC coatings effectively mitigated the corro-sive impact of synthetic seawater, providing a robust protective barrier for high-precision steel components.

Abstract: Ice accumulation on critical infrastructure surfaces threatens operational safety in aviation, power transmission, and transportation systems. Conventional anti-icing and deicing strategies, such as chemical deicers and energy-intensive active heating, have inherent drawbacks. These include environmental pollution, high energy consumption, and low efficiency. In recent years, photothermal-responsive superwetting surfaces have attracted widespread attention. They can harvest renewable solar energy and achieve efficient anti-icing and deicing through tailored interfacial wetting properties. This review summarizes photothermal superwetting surfaces based on the “water as a lubricating layer” strategy. This strategy reduces ice adhesion strength and enables low-energy deicing. It works by forming a continuous lubricating film via photothermally induced interfacial meltwater. We discuss photothermal conversion mechanisms and strategies to enhance performance for stable lubricating film formation. We also analyze the stagewise physics of anti-icing and deicing, focusing on the interfacial tribological behavior of the water film. Key engineering challenges are addressed, including mechanical durability and all-weather applicability. Finally, we clarify future research directions for industrial translation. This review aims to provide theoretical insights and technical pathways for developing next-generation anti-icing and deicing surfaces that are efficient, eco-friendly, and sustainable.

Abstract: This work focuses on parametric optimisation and the prediction of performance for NiCr/WC-Co coatings prepared using high-velocity oxygen fuel (HVOF) spraying. An L18 orthogonal experimental design based on the Taguchi method and the response surface method (RSM) was adopted to examine how key process parameters affect the microstructure, phase composition and hardness of the coatings. A total of eight controllable factors were selected and the hardness, microstructure and phase characteristics of the coatings were evaluated using a Vickers hardness tester, scanning electron microscopy and X-ray diffraction. Analysis of variance (ANOVA) revealed that travel velocity, methane flow rate, powder feed rate and spraying distance were the dominant parameters affecting coating hardness, accounting for altogether 76.25% of the total variance.The model established in this study demonstrates remarkably high predictive accuracy, with a coefficient of determination (R²) of 0.985 and an average prediction error of just 1.16%. This model accurately reflects the nonlinear relationship between process parameters and coating hardness. Meantime, verification experiments were conducted under optimal conditions. The measured hardness was 1352.7 ± 75 HV, in close agreement with the predicted value of 1365 HV. This result has a relative error of 0.98%, which validates the reliability of the second-order model, and a dense layered structure, low porosity, and minimal decarburization of tungsten carbide are exhibited by the coating. Adding a NiCr intermediate layer improves interfacial bonding and reduces structural defects. It is demonstrated by the results that the Taguchi-RSM method is reliable for the optimization of HVOF spraying parameters and the prediction of coating hardness. Overall, this study provides technical support and industrial application for the preparation of high-performance NiCr/WC-Co ceramic-metal composite coatings.

Abstract: Green and biodegradable materials are also being considered as an alternative to the plastic-based products in the textile and packaging sectors as a sustainable alternative. In this study, four kinds of jute-based fabrics were used that included raw jute woven, bleached raw jute woven, jute-cotton union and bleached jute-cotton union subjected to a dip-pad-dry-cure to acquire water-repellent properties with the usage of Rucostar EEE6 (a C6-Fluorocarbon resin containing hyperbranched polymers in a hydrocarbon matrix). In the presence of acetic acid, finishing solutions of different concentrations of Rucostar EEE6 (120, 140 and 160 g/L) were prepared. Treated fabrics were dried at 100 °C at 30 mins and cured at 160 °C for 1 min to enhance fixation. Structural, chemical, mechanical, and functional characterizations were systematically performed to evaluate the performance of the treated fabrics. The use of Scanning Electron Microscopy (SEM) showed a consistent deposition of the finishing layer on the fiber surface and Fourier Transform Infrared (FTIR) spectroscopy showed that the resin chemically reacted with the hydroxyl groups of the jute cellulose. Tensile strength test was performed in order to determine the impact of finishing on the durability of fabrics. Contact angle, spray rating test (AATCC Method 22) and drop test were used to assess water-repelling performance. The contact angle of the treated fabric was more than 90, which confirms that the fabric is hydrophobic. It is important to note that the sample treated with 140 g/L of Rucostar EEE6 and cured at 160 °C had a spray rating value of 100, which means the highest water repellency level and a high degree of water penetration resistance. On the whole, the results indicate that jute fabric with fluorocarbon resin finish exhibits a considerable improvement in hydrophobic properties and retains mechanical strength and natural feel, which implies a high level of potential application in the sustainable development of the textile industry as an alternative to plastic bags.

Abstract: Organic coating is the most applied method for corrosion protection. However, they can degrade over time by the effect of UV, moisture, and corrosive media. In order to monitor the coating performance for proper maintenance planning, an electrochemical sensor was fabricated from aluminum alloy and coated with 4 coating systems: (1) epoxy primer, (2) epoxy primer/polyurethan topcoat, (3) epoxy primer/ polyurethan topcoat/ aluminum powder-containing polyester resin, and (4) epoxy primer/ polyurethan topcoat/ aluminum powder-containing polyester resin/ acrylic. The sensors were exposed together with corresponding coupon samples at Pathum Thani (PTI: suburban) and Chon Buri (CBI: mild marine) in Thailand for 2 years. Electrochemical impedance spectroscopy measurement (EIS) via the sensor recorded the impedance and capacitance of coatings with parallel meteorological monitoring. Impedance data were converted into a Coating Aging Index to evaluate degradation. Rapid coating deterioration occurred at PTI during wet seasons, while CBI showed negligible changes. Among the examined variables via machine learning model, exposure time most strongly influenced coating degradation. Single epoxy layer exhibited the lowest durability, whereas additional polyurethane, aluminum‑pigmented polyester, and acrylic coatings provided progressively superior protection.

Abstract: The current study was aimed to investigate anti-corrosion performance of multi-layer polymeric coatings applied on 6005A and 6082 aluminum alloys under influences of monsoon tropical climate in Thailand. The coated samples representing the material used for a vehicle body of high-speed train were exposed to actual atmosphere of urban (Bangkok City) and marine (Songkhla City) environments. The maximum duration of the continuous exposure test was 18 months. After completion of exposure test, the physical deterioration characteristics of coatings was examined with the aid of scanning electron microscopy (SEM). Electrochemical impedance spectroscopy (EIS) was conducted in 3.5 wt.% NaCl solution at 25C to evaluate the anti-corrosion coating performance after different exposure periods in atmospheric environments. Based on EIS results, the low-frequency impedance of the exposed coatings was higher than 109 cm2, meaning that the anti-corrosion coating could sufficiently protect the alloys against atmospheric corrosion attacks. However, the gradual degradation of anti-corrosion coating was also noted, particularly, when exposed at marine-coastal environment. The quantitative estimation results indicated that the anti-corrosion coating used in the current research could last for approximately 8 and 11 years when exposed in marine-coastal and urban environments, respectively.

Abstract: Microfluidics enables spatially controlled nanostructure synthesis by coupling confined flows with surface reactions. In this work, we study how geometry-induced laminar mi-cro-environments govern the in-situ formation of Au and Ag nanostructures inside 3D-printed microfluidic reactors. Proof-of-concept fish-scale valves were fabricated by masked stereolithography in three architectures designed to define three recurring zones in the microreactor, inside the scales (zone 1), between the scales (zone 2), and along the rows of scales (zone 3). A Cu thin film was deposited on the inner walls of the channel to serve as the sacrificial surface for galvanic replacement using AgNO3 or HAuCl4. Distinct 0D, 1D, and 2D nanostructures were simultaneously obtained in a zone-dependent man-ner across the valves, including nanoparticle and nanopore-rich regions, nanowires, nanoflakes and clustered 2D features. COMSOL simulations were used to solve the Na-vier-Stokes equation and extract specific-zone flow descriptors, including Reynolds num-ber, velocity, and wall shear stress, and relate them to the nanostructure morphologies observed by SEM. The flow throughout the devices is strongly laminar, with local Reyn-olds numbers up to 0.04, exhibiting systematic spatial gradients imposed by the valve geometry. These results provide a design-guided route to tune nanostructure morphology through microchannel architecture under constant global operating conditions.

Abstract: There is a strong and growing need for low environmental impact, fluorine-free finishes that deliver durable water repellency and stain resistance to leather while preserving its original appearance. This work successfully addresses this need by introducing a simple, robust, and scalable two-step coating strategy that endows leather surfaces with excellent hydrophobic and self-cleaning properties. The process relies on a straightforward spray application of functionalized silica nanoparticles followed by a hydrophobic silane, namely hexadecyltrimethoxysilane (HDTMS), enabling precise control over surface properties through the number of applied layers. Comprehensive characterization by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM–EDS) confirmed the effective formation and uniformity of the coating. Performance testing demonstrated excellent functional outcomes: the optimized coating achieved a water contact angle of 128° and maintained values above 125° even after abrasion, highlighting its durability. Treated leather exhibited resistance to common liquid stains such as tea and coffee, maintaining a clean surface. These functional gains were achieved without compromising the leather’s natural look or soft feel, even after multiple coating cycles. This work delivers a fluorine-free solution offering an effective route to high-value water- and stain-resistant leather finishes that respect both environmental and aesthetic requirements.

Abstract: The study continues the authors' previous research on The Impact of CO₂ Laser Treatment on Kevlar^® KM2+ Fibres Fabric Surface Morphology, using direct laser surface texturing of polymers. SEM and Confocal microscopy image analysis of Kevlar^® KM2+ 440D and 600 are performed to analyze the results. In the course of the study, the surface topography of Kevlar^® KM2+ fabric is optimized by adjusting the continuous wave (CW) CO2 laser parameters so that it increases the surface roughness before graphene coating and resistance to yarn pulling out of the fabric without destroying the unique structure of Kevlar® KM2+ fibres. Experimental study measurement data indicate an increase in surface roughness by 50%, and a set of laser parameter variants has been obtained that allows increasing the yarn pulling out force of KM2+ woven fabric from the fabric in the range from 50% to 99%, compared to untreated fabric. The results obtained are potentially applicable for the production of composite materials against projectile fragmentation.

Abstract: Surface modification of metallic powders plays a critical role in improving their chemical stability, interfacial characteristics, and processing behavior in powder metallurgy applications. In this study, micron-sized iron powders were treated using a controlled gas-phase phosphating process to investigate surface layer formation and microstructural evolution. The influence of treatment conditions on phase stability, surface morphology, and elemental distribution was systematically analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). The results confirm the preservation of the body-centered cubic α-Fe phase within an optimized temperature range, while a conformal phosphate-based surface layer was successfully formed. Increased treatment severity led to partial surface oxidation and localized microstructural heterogeneity. Elemental mapping revealed homogeneous phosphorus distribution under controlled processing conditions, indicating uniform coating development. The study establishes clear correlations between gas-phase processing parameters and surface layer formation mechanisms. These findings provide insight into the controlled surface engineering of iron powders and offer practical guidance for optimizing gas-phase phosphating routes in advanced powder metallurgy and metallurgical applications.

Abstract: Zeolitic imidazolate framework-8 (ZIF-8) is one of the most extensively studied metal–organic frameworks due to its high surface area, tunable porosity, chemical stability, and intrinsic antimicrobial activity. Recent research has focused on engineering ZIF-8 through metal doping and surface functionalization to enhance its physicochemical performance and expand its applications in food safety and environmental systems. Metal-doped ZIF-8 incorporating Cu2+, Fe2+/Fe3+, Ag+, or Mn2+ improves reactive oxygen species generation, enables controlled metal-ion release, and promotes synergistic bactericidal mechanisms against both Gram-positive and Gram-negative pathogens. In parallel, surface modification using biopolymers such as hyaluronic acid, chitosan, alginate, and polyethylene glycol enhances colloidal stability, reduces cytotoxicity, modulates surface charge, and improves adhesion to food-contact surfaces. These combined strategies enable the development of multifunctional nanoplatforms with sustained antimicrobial activity, improved aqueous dispersibility, and compatibility with food packaging, sanitizers, and water treatment systems. This review summarizes recent advances in synthesis strategies, structure–property relationships, antimicrobial and antibiofilm mechanisms, and environmental safety considerations. Key challenges, including scalability, regulatory acceptance, stability, and long-term ecotoxicological impact, are discussed, along with perspectives on stimuli-responsive systems, essential oil encapsulation, and smart antimicrobial coatings.

Abstract: This article presents a reflective survey of research contributions that are related to functional thin film materials, photovoltaic-related architectures, and energy-oriented applications. By synthesising findings from multiple investigations focused on semiconductors, metal-oxide composite systems, nanostructured coatings, and building relevant constituents, the work concentrates on proceeding of fabrication strategies as well as structure-property interrelationships and application-driven performance metrics. Rather than giving a full review of the literature, the article combines some of the experimental observations to highlight recurrent themes such as process optimisation, interface engineering, and multifunctional material behaviour. Particular emphasis is placed on the modulation of optical, electrical, and functional performance by modest variations in deposition conditions, dopant incorporation strategies, and structural design. A cross-there theme analysis shows practical feasibility, long-term stability, and scalability as important as peak performance in determining the suitability of advanced materials for energy applications. Unlike conventional component-focused reviews, this perspective articulates a translational design logic linking materials processing decisions directly to device reliability and system-level energy performance, providing a conceptual framework for accelerating lab-to-field deployment of sustainable energy technologies. The purpose is to highlight cross-cutting translational challenges and design principles that link functional materials to device- and system-level deployment, with particular relevance to real-world and remote-environment energy applications.

Abstract: The lack of integrity at the implant-abutment junction (IAJ) contributes to problems such as micromovements and microbial colonization. This study aimed to (1) design a protocol for assessing microleakage at the IAJ using chromophore analysis that hasn’t been involved in other analysis, (2) compare gas and dye leakage using titanium (Ti) and cobalt chrome (CoCr) abutments, and (3) assess the effect of gold (Au) gilding on sealing. Forty abutments were divided into five groups: milled Ti (MTi); cast CoCr (CCoCr); milled CoCr (MCoCr); cast CoCr with Au gilding (CCoCrG); and milled CoCr with Au gilding (MCoCrG). Samples were connected to a pressurised gas and dye reservoir. Chromophore analysis using crystal violet was performed via UV-Vis spec-trometer to calculate leakage concentration. Scanning electron microscopy (SEM) analysis assessed surface morphology which revealed an intimate contact with the MTi and MCoCr but irregularities at the CCoCr abutments. Results showed gas leakage in CCoCr and MCoCr groups, while no true dye leakage occurred in MTi, MCoCr and MCoCrG assemblies. CCoCr exhibited the poorest seal; however, Au gilding improved the seal in these samples. Chromophore analysis using crystal violet provided an ac-curate quantitative assessment. Milled abutments demonstrated significantly less mi-croleakage than cast (non-gilded) versions, Au gilding effectively reduced leakage.

Abstract: The growing pollution caused by plastics with slow degradation kinetics is demanding the search for biodegradable alternatives. Starch-based films are a promising option, but their practical application may be limited by their potential susceptibility to rapid ultraviolet (UV) exposure degradation. This study evaluates the effect of prolonged UV-C irradiation (254 nm, 168 h) on plasticizer-free films derived from the starch of the Ecuadorian potato Solanum tuberosum (Chola variety). Films formulated at 3 % and 5 % (w/v) starch were characterized before and after UV exposure. The analysis includes the evaluation of optical, mechanical, and physicochemical properties, along with Fourier Transform Infrared spectroscopy (FTIR) and atomic force microscopy (AFM) for nanoscale surface inspection. UV irradiation increased the opacity of the films but reduced slightly their tensile strength, elongation at break, moisture content, and total soluble matter. In contrast, the elastic modulus remained relatively high. FTIR analysis revealed no significant formation of new functional groups, suggesting that UV exposure induces a physical reorganization rather than chemical degradation. AFM measurements indicated that irradiation caused only minor nanoscale alterations in the same film regions. These alterations were more pronounced in films with higher starch concentrations. The results demonstrate that UV-C exposure induces minor structural adjustments in plasticizer-free starch films derived from the Chola variety, without compromising their fundamental integrity. Consequently, this work advances the understanding of the environmental stability of these films and supports their potential application as sustainable materials, even in conditions involving UV exposure.