Chemistry and Materials Science

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.

Abstract: Vividly colored cholesteric liquid crystal polymer network (CLCN) patterns based on epoxy resin are used in decorative and anti-counterfeiting applications. These films are typically prepared via cationic photopolymerization and post-polymerization to achieve a high cross-linking degree. In this work, the cross-linking degree is controlled by varying the UV irradiation dosage during photopolymerization. Following this, the reflection band of the CLCN film changes after removing non-cross-linked compounds with acetone. Leveraging the low cationic polymerization rate and the chain termination capability of methanol, a structurally colored CLCN film with regionally tailored cross-linking was fabricated. With the treatment of acetone, a colorful pattern was observed. Moreover, upon immersion in methanol, the film swells, revealing a colorful pattern. After the evaporation of methanol, the pattern disappeared. Consequently, this CLCN film holds significant potential for information encryption applications.

Abstract: This study introduces a hybrid optimization method to enhance the melting characteristics and weld bead morphology of flux-cored wire hardfacing with exothermic addition into the core filler. The Taguchi Design of Experiments (L9 orthogonal array) was used to analyze the effects of key conditions on multiple melting characteristics. The hybrid Taguchi-GRA-PCA effectively identified the best parameter combination, resulting in a significant improvement in overall melting performance. The impact of welding modes on weld bead parameters and melting characteristics was examined. It was determined that the optimal amount of the exothermic addition CuOAl introduced into the flux-cored wire filler should be at a medium level (EA = 28 wt.%). Results showed that wire feed speed WFS and EA had the greatest effect on MOR and DR, while EA and CTWD mainly influenced SF and De. It has been determined that the content of the exothermic additive has a significant impact on the melting process of filler materials, affecting the melting characteristics and weld bead morphology. It has been found that the melting characteristics of deposition rate and spattering factor can be used to optimize welding modes and characterize most output parameters of the welding/surfacing process.

Abstract:

This work introduces a new method for creating patterned SiO₂ electrets using Electrode-Free Electrochemical Nanolithography (EFEN), enabling surface functionalisation without direct electrode contact. EFEN applies an alternating current through capacitive coupling between a conductive stamp and an insulating substrate in high-humidity conditions, forming a nano-electrochemical cell that drives localised reactions. Using thermally grown SiO₂ films, we achieve submicrometre patterning with minimal topographical impact but significant electronic alterations. Characterisation via Kelvin Probe Force Microscopy and Electric Force Microscopy confirms the formation of charged regions replicating the stamp pattern, with adjustable surface potential shifts up to –1.7 V and charge densities reaching 300 nC·cm⁻². The process can be scaled to areas of 1 cm² and is compatible with conventional laboratory equipment, offering a high-throughput alternative to scanning-probe lithography. EFEN combines simplicity, accuracy, and scalability, opening new opportunities for patterned electret production and functional surface engineering.

Abstract: Sluggish oxygen reduction reaction (ORR) remains a critical barrier to advancing intermediate-temperature electrochemical energy devices. Here, we demonstrate that strain engineering in two platforms, epitaxial thin films and freestanding membranes, systematically tunes ORR kinetics in Ruddlesden-Popper LaSrCoO4. In epitaxial films, the thickness is varied to control in-plane tensile strain, whereas in freestanding membranes strain relaxation during the release step of fabrication with water soluble sacrificial layers produces flat or wrinkled architectures. Electrochemical impedance spectroscopy analysis reveals more than an order of magnitude increase in the oxygen surface exchange coefficient for tensile-strained films relative to relaxed films, together with a larger oxygen vacancy concentration. Wrinkled freestanding membranes provide a further increase in oxygen surface exchange kinetics and a lower activation energy, which are attributed to increased active surface area and local strain variation. These results identify epitaxial tensile strain and controlled wrinkling as practical design parameters for optimizing ORR activity in Ruddlesden-Popper oxides.

Abstract: Graphene (GRA) and graphene oxide (GO) have drawn significant attention in materials science, chemistry, and nanotechnology because of their tunable physicochemical properties and wide range of potential uses in biomedical and environmental applications. Building reliable, large-scale molecular models of GRA and GO is essential for molecular simulations of wetting, adsorption, and catalytic behavior. However, current methods often struggle to generate large, chemically consistent sheets at high oxidation levels. In addition, the resulting structures are frequently incompatible across different simulation packages. This work introduces a step-by-step protocol with custom Tool Command Language (Tcl) and modified Python scripts for building large-scale, AMBER-compatible GO structures with oxidation levels from 0% to 68%. The workflow applies a systematic surface modification strategy combined with post-processing and atom-type assignment routines to ensure chemical accuracy and force field consistency. The dataset includes fifteen MOL2 format files of 20 × 20 nm² GO sheets, ranging from pristine to highly oxidized surfaces, each validated through oxidation-ratio analysis and structural integrity checks. Together, the dataset and protocol provide a design of scalable and chemically reliable GO molecular models for molecular dynamics simulations.

Abstract: This work presents an approach to water-dispersible polylactide (PLA) particle fabrication and their application in low-temperature film formation using a combination of mechanical dispersion and ultrasonication techniques. Stable PLA dispersions were obtained after removal of surfactant and allowed for the preparation of thin films exhibiting significantly reduced minimum film-formation temperature (MFFT), particularly when plasticized. To tailor the interfacial behavior and mechanical flexibility of the resulting coatings, a set of conventional and bio-based plasticizers was evaluated, including epoxidized fatty acids, PEG-400, and several hydrophobic deep eutectic solvents (HDES) synthesized from menthol and carboxylic acids. Compatibility between PLA and each plasticizer was predicted using Hansen solubility parameters, and the efficiency of plasticization was assessed through glass-transition temperature suppression in solvent-cast films. The combination of submicron PLA particles and selected plasticizers enabled film formation at temperatures as low as 48 °C, confirming the potential of these systems for energy-efficient coating technologies. Furthermore, composite coatings incorporating micro sized cellulose fibers regenerated from agricultural residues were successfully obtained, demonstrating the feasibility of integrating bio-derived fillers into waterborne PLA formulations. This study highlights the use of water-insoluble ionic-liquid-type plasticizers for PLA dispersions and establishes a foundation for developing sustainable, low-VOC, and low-temperature PLA-based coating materials.