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.

Abstract:

Titanium dioxide (TiO₂) thin films were deposited by DC magnetron sputtering and subsequently treated in hot water at 50, 70 and 95 °C for 72h to investigate the influence of low-temperature on their structural optical and functional properties. XRD analysis revealed a progressive transformation from amorphous to anatase phase with increasing treatment temperature, accompanied by an increase in crystallite size from 5.2 to 15.1 nm. FT-IR spectroscopy confirmed enhanced surface hydroxylation, while contact-angle measurements showed a decrease from 77.4° to 19.7°, indicating a significant improvement in superior wettability. The transmittance spectroscopy revealed a slight narrowing of the optical band gap from 3.34 to 3.21 eV, consistent with improved visible-light absorption. Photocatalytic tests using the Resazurin indicator demonstrated that the film treated at 95 °C exhibited the highest activity, achieving a time to bleach of 245 s three times faster than treated at 50°C and twice as fast as treated at 70°C. Under low-intensity solar irradiation, the same sample achieved complete E. coli inactivation within 90 min. These improvements are attributed to increased crystallinity, surface hydroxyl density, and enhanced ROS generation. Overall, this study demonstrates that mild hot-water treatment is an effective, substrate-friendly route to enhance TiO₂ film wettability and multifunctional performance, enabling the fabrication of self-cleaning and antibacterial coatings on fragile materials such as plastics and textiles.

Abstract: Produced well flow is controlled through valves placed in the Christmas tree. Being mostly gate-type valves, they isolate the well from the surface when commanded or automatically in an emergency. The reliability of these valves is essential for subsea wells, as maintenance and replacement involve high cost, time, and HSE risks. Their design must withstand harsh conditions such as high temperature, pressure, solid particles, and corrosive environments. However, failures caused by leakage, cold welding, and the erosion of sealing elements are still common. These issues motivated the initial stage of this research, which experimentally showed that replacing the current tungsten carbide (WC) coating with polycrystalline diamond compact (PDC) material reduces friction and wear due to its high hardness and thermal stability. Based on these results, a 3D subsea gate valve model was developed and simulated in Ansys Fluent 2024 R2 under API slurry test conditions using the Oka erosion and Discrete Phase Models. A comparative analysis of WC and PDC coatings for a 5-inch gate valve exposed to a 2% sand slurry (250–400 μm) showed that PDC reduces the erosion depth by 77.6% and extends the valve lifetime by 4.5 times. The findings support the use of PDC for improved erosion resistance in subsea valve applications.

Abstract: Microstructure of composite films composed of polymers and nanoparticles is crucial for understanding the nanoparticles (NPs) dispersion and the role by colloidal stability played in the film formation process. The research aims to create composite films from the combination of hy-aluronic acid (HA) and zinc oxide nanoparticles (ZnO NPs) to produce materials that integrate an-timicrobial properties as a medical application interface. The main problem of composite films involving ZnO NPs is dispersion in polymer matrix which compromises mechanical integrity and structure performance. We discovered key parameters of phase separation influenced by ther-modynamic factors and then observed interfacial compatibility through a nanoscale resolution ZnO NPs dispersion, its adhesion mechanisms and defect distribution. We utilized a pH driven HA/ZnO electrostatic reaction by generating a protonation without any form of chemical change, using citric acid as stabilizing agent and this reverses the Zeta potential of the filler (ZnO NPs) to +25mV , and then we used atomic force microscopy (AFM) to study the microstructure of the films and optical microscope for the morphology. The process also covers surface modification of ZnO through PEGylation. The AFM analysis showed that surface roughness and particle size vary with respect to whether the ZnO nanoparticles were functionalized, unmodified or chelated. The research results will help create HA-based composite films and microneedles with specific nanostructures for wound healing and drug delivery administration.

Abstract: The chemical machining of copper is a ubiquitous process in electronics manufacturing used to create conductor patterns for printed circuits among a variety of electronic components. Popular etchants for this process are high-ionic-strength solutions of acidic ferric chloride, acidic cupric chloride, and alkaline cupric ammine chloride, which face challenges arising from passivity and stability of the dissolved metals, particularly in alkaline solutions. While these concepts are common to electrodissolution, they are not well-reviewed for systems which do not apply external voltage, as is the case for chemical machining, where complimentary redox reactions occur spontaneously and simultaneously on the same surface of the workpiece. This article serves to review the most influential challenges posed against copper chemical machining reactions through passivation and factors leading to precipitation of metal species in each of the three common etchants of transition metal salts. Academic texts are referenced in conjunction with primary evidence to introduce novel insight regarding the implications of ion transference in the electrolyte solutions and ligation effects in preventing hydrolysis in addition to opportunities for further research identified throughout the article.

Abstract: Addressing the urgent need for low-temperature processes in the manufacturing of flexible vehicle-mounted touch display devices, this study investigates the process-structure-performance relationships of indium tin oxide (ITO) thin films prepared by DC magnetron sputtering at temperatures far below the tolerance limit of transparent polyimide (CPI). By systematically adjusting the substrate temperature (30-300°C) combined with 230°C atmospheric annealing, a unique optimization effect was identified at the moderate deposition temperature of 110°C. Experimental results show that the sample deposited at 110°C followed by annealing exhibits optimal comprehensive performance: resistivity as low as 203 μΩ·cm, average visible light transmittance of 89.2%, surface roughness of 0.76 nm, and the ability to endure 100,000 bending cycles at a bending radius of R = 5 mm with a sheet resistance change rate of less than 10%. Microstructural analysis reveals that this process facilitates the complete conversion of Sn²⁺ to Sn⁴⁺ and the controlled formation of oxygen vacancies, leading to a synergistic improvement in carrier concentration (8.7×10²⁰ cm⁻³) and mobility (35.2 cm²/V·s). This work elucidates the crystallization kinetics and doping mechanisms of ITO thin films under low-temperature conditions, offering important theoretical foundations and technical pathways for the low-temperature fabrication of high-performance transparent electrodes in flexible vehicle-mounted touch display devices.

Abstract: Accurate prediction of surface morphology evolution is essential for virtual process development in semiconductor manufacturing. We present SimProfile, a flexible surface profile simulator based on the Monte Carlo method, capable of modeling both plasma etching and deposition processes. SimProfile incorporates detailed surface interaction models, including chemical reactions, sputtering, redeposition and reflection dynamics, to reproduce anisotropic profile evolution in complex plasma environments. A key feature of the simulator is its data-driven parameter calibration framework, which calibrates uncertain process parameters, such as reaction probabilities and sputtering yields, using experimental SEM images. By iteratively minimizing the discrepancy between simulated and measured profiles, SimProfile enables high-fidelity simulations with minimal manual calibration. We demonstrate the effectiveness of this approach through a case study of \( SF_6 / O_2 \) plasma etching, showing good agreement between simulated and experimental trench geometries. SimProfile provides a robust foundation for data-assisted modeling of nanoscale surface processes in both etching and deposition applications.

Abstract: Transition metal cyanides form a diverse family of coordination compounds, exhibiting a range of interesting physical and functional properties. Such features are determined by the ability of that ligand to serve as an electron density bridge between the involved transition metal centers and the diversity of coordination modes for the cyanide ligand (CN¯). In fact, such an ability results in a coupling and overlapping of metals electron clouds. In that context, X-ray photoelectron spectroscopy (XPS) appears as an excellent tool for probing the interaction of the CN bridge with the bridged metal centers, the electron density on these last ones, their effective valence, the electron density redistribution effects, and many other features related to the electronic structure of these solids. This review discusses the scope of XPS for probing the electronic structure of the titled family of coordination polymers. Understanding the scope of using this spectroscopic technique for studying these materials opens up new opportunities for engineering their potential applications.

Abstract:

This study investigated the effect of Lawsonia inermis extract as a natural additive to improve the performance of zinc-rich silicate-based coatings on carbon steel. The paint films were prepared with extract concentrations of 0-12 wt% and analyzed by FTIR, XRD, XRF, SEM. The corrosion resistance was evaluated by electrochemical measurements (EIS, potentiodynamic polarization) after 35 days of immersion in 3.5 wt% NaCl solution. The results indicated that a 5 wt% concentration was optimal, as it improved the microstructure of the paint film, leading to a denser and more homogeneous coating. Electrochemical measurements confirmed that this sample exhibited the highest impedance and polarization resistance after testing, which demonstrates enhanced corrosion resistance. The study concluded that the henna extract serves a dual role as both a corrosion inhibitor and a microstructure modifier. The use of natural additives at optimal concentrations is considered a potential approach to improve the effectiveness of protective coating systems.

Abstract:

Highly Luminescent carbon quantum dots (CQDs) and copper-doped CQDs (Cu-CQDs) were synthesized from Asafoetida powder using a one-pot hydrothermal method. The structural, morphological, and optical properties of the synthesized CQDs were characterized via microscopic and spectroscopic techniques. Photoluminescence studies revealed that CQDs exhibited maximum emission at 450 nm under 335 nm excitation with a quantum yield of 37%, while Cu-CQDs showed a red-shifted emission at 455 nm under 330 nm excitation and a significantly enhanced quantum yield of 73.4%. As proof of concept for potential biomedical and surface-coating applications, the antimicrobial activity of both CQDs was evaluated against Escherichia coli (E. coli) and Staphylococcus aureus (S. Aureus). Cu-CQDs exhibited superior antibacterial efficacy, with a minimum inhibitory concentration of 0.3 mg/mL. Furthermore, Cu-CQDs were immobilized on polyvinyl chloride (PVC) surfaces, and fluorescence microscopy confirmed their antibacterial effectiveness, demonstrating their potential for functionalized antimicrobial coatings.

Abstract: This study systematically investigates the surface nanocrystallization mechanism of 35CrMo high-strength low-alloy (HSLA) steel induced by ultrasonic surface rolling processing (USRP), with particular emphasis on elucidating its optimization effects on surface integrity, mechanical properties, and wear resistance. Through USRP treatment with varying static pressure parameters combined with multi-scale characterization techniques, we demonstrate that high-frequency impact and rolling effects promote martensite lath fragmentation and dislocation multiplication, thereby forming a gradient nanostructured layer composed of equiaxed nanocrystals and high-density dislocations in the surface region. After USRP treatment, the surface roughness was minimized to 0.029 μm, attributed to the synergistic "peak-cutting and valley-filling" effect and plastic flow-induced surface smoothening. Concurrently, compressive deformation during rolling induces lattice distortion effects, successfully transforming the residual stress state from tensile to high compressive stress. A remarkable 32.3% enhancement in surface microhardness was observed, primarily originating from multiple strengthening mechanisms including grain refinement, dislocation strengthening, and carbide dispersion strengthening, with an effective hardened layer depth reaching 300 μm. In terms of wear performance, the USRP-0.35 MPa sample exhibited optimal wear resistance with a 28.9% reduction in mass loss, owing to the significantly improved load-bearing capacity of the gradient nanostructured layer and effective suppression of crack initiation and propagation by compressive residual stresses. High-resolution electron microscopy and diffraction analyses captured the dynamic evolution process of dislocations, from their initiation at martensite boundaries to subsequent propagation and eventual formation of dislocation pile-ups and subgrain boundaries, providing direct experimental evidence for the Hall-Petch and Taylor strengthening theories. This work not only clarifies the microscopic mechanisms of USRP-induced surface strengthening in 35CrMo steel but also offers important theoretical guidance and practical references for optimizing surface treatment processes of high-strength alloy components.

Abstract: Palladium-based membranes for hydrogen separation offer the most promising gas permeation and selectivity, but their large-scale application has been limited due to the high environmental burdens and criticality of palladium. Herein, the possibility of substituting Pd with candidate elements in the composition of metallic membranes deposited via High Power Impulse Magnetron Sputtering (HiPIMS) was investigated. This study proposed an innovative framework for a more comprehensive investigation of the sustainability challenges related to this lab-scale technology by integrating LCA and criticality analyses, thereby supporting materials selection efforts. First, the criticality status of several elements used in hydrogen separation membranes was screened with two different approaches. Furthermore, the environmental impacts of novel membrane compositions were compared with a high Pd-content reference membrane (Pd77Ag23) through cradle-to-gate Life Cycle Assessment (LCA). For robust LCA modeling, uncertainty analysis was performed via Monte Carlo simulation exploiting errors estimated for primary data. A direct relationship was identified between the Pd content in membranes and the associated environmental impacts. VPd membranes proved to be the most promising candidate by exhibiting 65% lower total impacts than the PdAg membrane while maintaining a high hydrogen permeability performance.

Abstract: Footwear is traditionally manufactured using non-biodegradable polymers and leather, raising well-documented environmental and health concerns related to their production and disposal. This study explores polyhydroxyalkanoates (PHAs) as sustainable alter-natives for bio-based footwear components. A stable aqueous suspension of PHBHHx was successfully formulated and applied to cotton fabrics via knife-coating. Various formulations, with and without additives and employing natural or synthetic thicken-ers, were evaluated in terms of surface morphology, wettability, permeability, and du-rability. The 10% PHBHHx formulation provided the best balance between material ef-ficiency, coating uniformity, and surface performance. Additives and thermal treatment both influenced wettability, reducing contact angles and enhancing water vapor per-meability. Notably, coatings with additives and hot pressing exhibited the highest permeability (68.0 ± 3.1 L/m²/s; 651.0 ± 5.4 g/m²/24 h), while additive-free, non-pressed coatings showed significantly lower values (19.5 ± 4.4 L/m²/s; 245.6 ± 66.2 g/m²/24 h), likely due to excessive compaction. Abrasion resistance remained excellent across all samples, especially with thermal treatment, withstanding 51,200 cycles. Washing re-sistance results revealed a synergistic effect between additives and heat, promoting long-term hydrophobicity and coating adhesion. Overall, PHBHHx coatings demon-strated potential to enhance water resistance while maintaining breathability, repre-senting a sustainable and effective solution for functional and technical footwear applications.

Abstract: Developing sustainable textile finishes that enhance moisture management and breathability remains a significant challenge in designing high-performance apparel. In this study, we propose an eco-friendly coating strategy utilizing an aqueous dispersion of poly(3-hydroxybutyrate)-diol (PHB.E.0), a member of the polyhydroxyalkanoate (PHA) family. This coating was applied to woven polyester (PES) and cotton (CO) fabrics using a low-impact spray-coating technique, aiming to improve functional properties while maintaining environmental sustainability. This solvent-free process significantly reduces chemical usage and energy demand, aligning with sustainable manufacturing goals. Successful deposition of the coating was confirmed by scanning electron microscopy (SEM), attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), elemental (C/O) analysis, and thermogravimetric analysis (TGA), which also revealed substrate-dependent thermal behaviour. Wettability, water absorption, and permeability tests showed that the coated fabrics retained their hydrophilic character. PHB.E.0 coatings led to a significant reduction in air permeability, particularly after hot pressing at 180 °C, from ≈670 to ≈171 l/m²/s for PES and from ≈50 to ≈30 l/m²/s for CO, without compromising water vapor permeability. All coated samples maintained high breathability, essential for wearer comfort. These results demonstrate that PHB.E.0 coatings enhance wind resistance while preserving moisture vapor transport, offering a sustainable and effective solution for functional sportswear.

Abstract: Acetaminophen (APAP) is a widely used pharmaceutical increasingly detected as a contaminant in aquatic environments due to its persistent nature and incomplete removal by conventional wastewater treatment. This study investigates the adsorption performance and mechanisms of commercial activated carbon (M) and its hydrothermally modified form (MH) for APAP removal. Characterization via elemental analysis, X-ray photoelectron spectroscopy (XPS), and N2 adsorption isotherms revealed that hydrothermal treatment reduced oxygen content and enhanced micro- and mesopore volumes, resulting in a more homogeneous and carbon-rich surface. Batch adsorption experiments conducted under varying pH (5–7) and temperature (30–40 °C) conditions showed that MH achieved up to 94.3% APAP removal, outperforming the untreated carbon by more than 15%. Kinetic modeling indicated that adsorption followed a pseudo-second-order mechanism (R² > 0.99), and isotherm data fitted best to the Langmuir model for MH and the Freundlich model for M, reflecting their differing surface properties. Adsorption was enhanced at lower pH and higher temperatures, consistent with an endothermic and pH-dependent mechanism. Complementary density functional theory (DFT) simulations confirmed that π–π stacking is the dominant interaction between APAP and the carbon surface. The most favorable configuration involved coplanar stacking with non-oxidized graphene (ΔG = −33 kJ/mol), while oxidized graphene models exhibited weaker interactions. Natural Bond Orbital (NBO) analysis further supported the prevalence of π–π interactions over dipole interactions. These findings suggest that surface deoxygenation and improved pore architecture achieved via hydrothermal treatment significantly enhance APAP adsorption, offering a scalable strategy for pharmaceutical pollutant removal in water treatment applications.

Abstract: The impact of a molten droplet on a solid surface, forming a “splat,” is a fundamental phenomenon observed across numerous industrial surface engineering techniques. For example, thermal spray deposition is widely used to create metal, ceramic, polymer, and composite coatings that are vital for aerospace, biomedical, electronics, and energy applications. Significant progress has been made in understanding droplet impact behavior, largely driven by advancements in high-resolution and high-speed imaging techniques, as well as computational resources. Although droplet impact dynamics, splat morphology, and interfacial bonding mechanisms have been extensively reviewed, a comprehensive overview of the mechanical behaviors of single splats, which are crucial for coating performance, has not been reported. This review bridges that gap by offering an in-depth analysis of bonding strength and residual stress in single splats. The various experimental techniques used to characterize these properties are thoroughly discussed, and a detailed review of the analytical models and numerical simulations developed to predict and understand residual stress evolution is provided. Notably, the complex interplay between bonding strength and residual stress is then discussed, examining how these two critical mechanical attributes are interrelated and mutually influence each other. Subsequently, effective strategies for improving interfacial bonding are explored, and key factors that influence residual stress are identified. Furthermore, the fundamental roles of splat flattening and formation dynamics in determining the final mechanical properties are critically examined, highlighting the challenges in integrating fluid dynamics with mechanical analysis. Thermal spraying serves as the primary context, but other relevant applications are briefly considered. Cold spray splats are excluded because of their distinct bonding and stress generation mechanisms. Finally, promising future research directions are outlined to advance the understanding and control of the mechanical properties in single splats, ultimately supporting the development of more robust and reliable coating technologies.

Abstract: A theoretical study of the adsorption of lithium sulfur molecules (Li2S and Li2S2) on graphene with three and four vacancies was conducted. The study analyzed the stabil-ity, adsorption geometry, electronic structure, charge distribution, and forming bonds between the molecule and the substrates. It has been demonstrated that both types of defects result in stable adsorptions; however, the underlying mechanisms differ. The three-vacancy graphene exhibits a site that favors the adsorption through bonds be-tween S atoms and the substrate, while the graphene with four vacancies promotes the anchoring of molecules through Li atoms. The mechanism associated with the three-vacancy graphene results in increased exothermic adsorption energies.

Abstract: The Ti6Al4V alloy is considered the most beneficial of the titanium alloys for use in bio-medical applications. However, it corrodes when exposed to various biocompatible fluids. This investigation aims to evaluate the corrosion inhibition performance of the Ti6Al4V in a saline solution (SS) using thiocolchicoside (TCC) drug as an environmentally acceptable corrosion inhibitor. The corrosion assessments were conducted using potentiodynamic po-larization curves (PPCs), open-circuit potential (OCP), and electrochemical impedance spec-troscopy (EIS) methodologies, supplemented by scanning electron microscopy (SEM), ener-gy-dispersive X-ray (EDS) analysis, atomic force microscopy (AFM), and contact angle (CA) measurements. The outcomes indicated that the inhibitory efficacy improved with higher TCC concentrations (achieving 92.40% at 200 mg/l of TCC) and diminished with an increase in solution temperature. TCC’s physical adsorption onto the surface of the Ti6A14V, which adheres to the Langmuir adsorption isotherm, explains its mitigating power. The TCC acts as a mixed-type inhibitor. The adsorption and inhibitory impact of TCC were examined at various temperatures using PPC and EIS. When TCC is present, the corrosion's apparent activation energy is higher (35.79 kJ mol-1) than when it is absent (14.46 kJ mol-1). In addition, the correlation between the structural properties of thiocolchicoside (TCC) and its corrosion inhibition performance was systematically analyzed. Density Functional Theory (DFT) calculations were utilized to characterize the adsorption mechanism, supported by Natural Bond Orbital (NBO) analysis and Molecular Dynamics (MD) simulations. The combined computational and electrochemical findings confirm that TCC provides effective and enhanced corrosion protection for the Ti6Al4V alloy in a saline environment. These characteristics provide compelling evidence for the suitability of these pharmaceutical compounds as promising corrosion inhibitors.

Abstract: Roll-to-roll production of thin organic and large-area electronic (TOLAE) devices often involves a 2-step process per functional layer: an un-pattered continuous deposition of the film and subsequent structuring process by for instance laser ablation. Thin film organic devices should be protected using ultra-barrier films. To perform laser ablation of functional layers on top of such barrier films, in particular that of transparent electrodes, an unprecedented selectivity of laser ablation is required to completely remove the layers without damaging the thin-film barrier layers underneath. When performing highly-selective laser ablation of indium tin oxide (ITO) on top of silicon nitride (SiN) barrier layers, we observed the emergence of visible large-scale patterns due to local variations in ablation quality. Our investigations using a very sensitive Raman spectroscopy setup show that the ablation variations originate from minute optical path length differences present in the heat-stabilized plastic substrates and locally consequential destructive or constructive interference occurs between the reflected light from the back of the substrate and incoming laser beam. By performing laser ablation under an angle such that the reflected and incoming laser beam do not spatially overlap, highly-selective uniform laser ablation can be performed, even for two transparent overlapping layers.

Abstract: Bio-based lubricants are increasingly recognized as sustainable alternatives to petroleum-derived lubricants due to their biodegradability, low toxicity, and alignment with global regulatory and environmental targets. Derived primarily from vegetable oils and other renewable feedstocks, these lubricants demonstrate promising tribological properties but still face technical and economic challenges, including oxidative instability, thermal degradation, and cost competitiveness in high-performance applications. This review synthesizes recent advancements in feedstock innovations, chemical modification strategies, and additive technologies aimed at improving stability, wear resistance, and frictional performance. Special attention is given to global market trends, industrial adoption, and regulatory frameworks shaping commercialization. Furthermore, the review highlights emerging methodologies for tribological evaluation and benchmarks performance across automotive, industrial, and marine sectors. By integrating recent findings with case studies and comparative data, the paper identifies critical research gaps and outlines future perspectives for the widespread adoption of bio-based lubricants in mainstream applications.