Search Results (13,885)

We fabricated TiO₂ thin films using the sol–gel method, incorporating TiO₂ nanoparticle sizes of 25 nm on the fluorine-doped tin oxide (FTO) substrates by spin coating and annelation at 600 °C. The influence of incorporating TiO₂ particles on the surface morphology, optical properties, and photovoltaic performance of TiO₂ thin-film dye-sensitized solar cells (DSSC) was examined. Structural characterization was analyzed using X-ray diffraction (XRD), while the morphologies were analyzed using scanning electron microscopy (SEM). The transmittance and absorbance of films were measured using an ultraviolet (UV)–visible (VIS)–near-infrared (NIR) spectrophotometer. The current–voltage (I-V) property was evaluated under simulated solar irradiation. The results demonstrated that the incorporation of TiO₂ particles enhanced the efficiency of DSSCs. The photovoltaic performance of DSSCs was improved with TiO₂ nanoparticle incorporation. The optimized DSSC incorporated TiO₂ films (TIFNA). TIFNA achieved a Jsc of 14.49 mA/cm², Voc of 0.69 V, fill factor of 60.5%, and efficiency of 6.05%, compared to 4.23% for the DSSC with unincorporated TiO₂ thin film. The improved performance was attributed to increased dye adsorption, better crystallinity, and enhanced electron transport. Full article

Hopeite (Zn₃(PO₄)₂·4H₂O) coatings, fabricated via zinc phosphate chemical conversion (ZPCC), have attracted considerable interest in biomedical applications owing to their excellent corrosion resistance and biocompatibility. However, the influence of calcium nitrate (CN) on coating properties remains poorly understood. This study systematically investigates the effect of CN concentration on the microstructure and corrosion behavior of ZPCC coatings deposited on stainless steel (SS). The phase composition, surface morphology, and elemental distribution were characterized using X-ray diffraction (XRD) and scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS). Electrochemical corrosion performance was assessed via potentiodynamic polarization in a 0.9 wt.% NaCl solution. The results indicate that CN concentration critically influences coating morphology, with higher concentrations leading to reduced crystal size and increased coating mass. Notably, the coating prepared with 6 g/L CN exhibited a dense, uniform, and fine-grained microstructure, resulting in superior corrosion resistance. Additionally, the optimized coating demonstrated strong interfacial adhesion, with a shear strength of 10.05 ± 1.2 MPa. Full article

This study systematically investigates the effects of aging treatment (AT) on the microstructure and properties of Cr/DLC coatings deposited via cathodic arc ion plating onto the surface of ECAP-7075 aluminum alloy. Utilizing a comprehensive approach combining performance tests (nanoindentation, nanoscratch testing, dynamic polarization analysis) with characterization tests (scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy), the synergistic effects of equal channel angular pressing (ECAP) and aging treatment(AT) were elucidated. The results demonstrate that the combined ECAP and AT significantly enhance the coating’s performance. Specifically, AT promotes the precipitation of η’ phase within the 7075 aluminum alloy substrate, increases the size of Cr₇C₃ crystallites in the Cr-based interlayer, improves the crystallinity of the Cr₇C₃ phase on the (060) or (242) crystal planes, and elevates the sp³-C/sp²-C ratio in the diamond-like carbon(DLC) top layer, leading to partial healing of defects and a denser overall coating structure. These microstructural transformations, induced by AT, result in substantial improvements in the mechanical properties (hardness reaching 5.2 GPa, bond strength achieving 15.1 N) and corrosion resistance (corrosion potential increasing to -0.698 V) of the Cr/DLC-coated ECAP-7075 aluminum alloy. This enhanced combination of properties makes these coatings particularly well-suited for high-performance aerospace components requiring both wear resistance and corrosion protection in demanding environments. Full article

Directed cell migration is crucial for numerous biological processes, including tissue regeneration and cancer metastasis. However, conventional symmetrical micropatterns typically result in bidirectional cell migration guidance instead of unidirectional guidance. In this study, polydimethylsiloxane (PDMS)-based platforms with asymmetrical arrowhead micropatterns, nanopillars, and selective fibronectin coating were developed to enhance unidirectional cell migration. The platforms were fabricated using nanoimprint lithography and PDMS replication techniques, allowing for precise control over surface topography and biochemical modification. The MC3T3 osteoblastic cells cultured on these platforms demonstrated significantly enhanced directional migration, characterized by increased displacement, and directional alignment with micropattern orientation compared to symmetrical patterns. Quantitative analyses revealed that asymmetrical arrowheads combined with nanopillars induced more focal adhesions and F-actin polarization at cell front regions, supporting the observed unidirectional cell migration enhancement. These results confirm that integrating micropattern asymmetry, nanoscale features, and biochemical functionalization synergistically promotes unidirectional cell migration. The developed platforms offer valuable insights and practical strategies for designing advanced biomaterials capable of precise spatial cell guidance that can be applied to the designs of organ-on-a-chip systems. Full article

Fatigue failure of overhead line conductors made of AlMgSi alloys is much more complex than fatigue failure of a single wire. The main difference lies in the fretting phenomenon, which is a significant mechanism initiating fatigue damage. It is generated because of micro-movements between individual wires or outer wires and overhead line fittings. Such movements are mainly caused by aeolian vibrations, which lead to degradation of wire surface, initiation of microcracks, and premature failure of multiple wires. Research based on laboratory experiments and modeling studies simulating real operating conditions made it possible not only to identify the mechanisms leading to failure but also to assess the impact of working conditions on their evolution. According to the obtained results, properly selected heat treatment parameters influence both the mass decrease of the wires and number of cycles to failure due to fretting fatigue. Further development of materials, protective coatings, and methods of durability prediction will reduce the impact of fretting on fatigue failure and thus increase the reliability of power lines. Full article

Chemical vapor deposition (CVD) is a crucial technique for fabricating high-performance amorphous silicon coatings, leveraging its process flexibility and microstructural controllability. Optimizing processes like hot-wire chemical vapor deposition, plasma-enhanced chemical vapor deposition, and catalytic chemical vapor deposition enable precise regulation of coating density, surface roughness, and chemical bonding. These amorphous silicon coatings exhibit outstanding tribological properties and exceptional corrosion resistance, primarily attributed to their unique amorphous structure eliminating grain boundary defects and forming dense passivation films. Future research should focus on intelligent process development, multi-field coupling failure analysis, environmental friendliness enhancement, and lifespan prediction models to advance this technology. Full article

In this study, glucose is used as the source of C; through cathode plasma electrolytic deposition technology, a carbon nano coating is prepared on the surface of carbon fiber. The carbon coating is analyzed using scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy to investigate the effect of pH on the microstructure of the carbon coating on the surface of carbon fiber. At the same time, the oxidation resistance of the coating and the changes in the tensile properties of carbon fiber after high-temperature heat treatment were also investigated. The results showed that reducing the pH value can improve the microstructure of the carbon coating, and the best performance of the carbon coating sample was obtained at pH = 3. The initial oxidation temperature and oxidation termination temperature increased by 156 °C and 110 °C, respectively, compared to the treated carbon fiber but without coating, and the tensile property remains a high value (2740 MPa) after high-temperature heat treatment. Full article

This review summarizes the recent advances in the application of nanomaterial coatings in optical fiber sensors, with a particular focus on deposition techniques and the research progress over the past five years in humidity sensing, gas detection, and biosensing. Benefiting from the high specific surface area, abundant surface active sites, and quantum confinement effects of nanomaterials, advanced thin-film fabrication techniques—including spin coating, dip coating, self-assembly, physical/chemical vapor deposition, atomic layer deposition (ALD), electrochemical deposition (ECD), electron beam evaporation (E-beam evaporation), pulsed laser deposition (PLD) and electrospinning, and other techniques—have been widely employed in the construction of functional layers for optical fiber sensors, significantly enhancing their sensitivity, response speed, and environmental stability. Studies have demonstrated that nanocoatings can achieve high-sensitivity detection of targets such as humidity, volatile organic compounds (VOCs), and biomarkers by enhancing evanescent field coupling and enabling optical effects such as surface plasmon resonance (SPR), localized surface plasmon resonance (LSPR), and lossy mode resonance (LMR). This paper first analyzes the principles and optimization strategies of nanocoating fabrication techniques, then explores the mechanisms by which nanomaterials enhance sensor performance across various application domains, and finally presents future research directions in material performance optimization, cost control, and the development of novel nanocomposites. These insights provide a theoretical foundation for the functional design and practical implementation of nanomaterial-based optical fiber sensors. Full article

A novel structure–functional-integrated particle featuring dual micromechanical interlocking property with resin matrix was constructed through surface modification of urchin-like serried hydroxyapatite (UHA) in this work, and the effect of this modification strategy on physicochemical and biological properties of dental resin composite was also investigated. A porous silica coating layer was anchored onto UHA surface via a simple template method in an oil−water biphase reaction system, and the coating time had a prominent effect on the coating thickness and morphology-structure of the particle. When these particles with different porous silica coating thickness were used as fillers for dental resin composite, results showed that UHA/PS5 (porous silica coating reaction time: 5 h) exhibited the optimal 3D urchin-like structure and a desirable porous silica coating thickness. Additionally, UHA/PS5 formed the best dual physical micromechanical interlocking structure when mixing with resin matrix, making the dental resin composites presented the desirable matrix/filler interfacial bonding, and the excellent physicochemical–biological properties, especially for flexural strength and water sorption-solubility. In vitro remineralization and cellular biological properties confirmed that the coating layer did not compromise their remineralization activity. The use of UHA/PSx provides a promising approach to develop strong, durable, and biocompatible DRCs. Full article

Although approximately half of global lithium consumption is used in the rechargeable battery industry, lithium is also in demand for other specialized applications, such as high-temperature lubricants, ceramics, glass, and pharmaceuticals. The growing need for efficient lithium recovery and recycling underscores the importance of fast and accurate analytical tools for determining lithium concentrations in non-compliant and waste materials generated by industrial processes. In this paper, we present a machine learning-based procedure utilizing Laser-Induced Breakdown Spectroscopy (LIBS) to accurately quantify lithium concentrations in lithium-rich non-compliant materials derived from the industrial production of enamels used for coating metallic surfaces. This procedure addresses challenges such as strong self-absorption and matrix effects, which limit the effectiveness of conventional univariate calibration methods. By employing a multivariate approach, we developed a single model capable of quantifying lithium content across a wide concentration range. A comparison of the LIBS results with those obtained using conventional laboratory analysis (Inductively Coupled Plasma–Optical Emission Spectrometry, ICP-OES) confirms that LIBS can deliver the speed, precision, and reliability required for potential routine applications in the lithium recovery and recycling industry. Full article

Hydrogel films are a promising class of materials due to their peculiar property of retaining water as well as responding to external stimuli. In contrast with conventional hydrogels, films provide enhanced responsiveness along with greater compliance to be integrated into devices as well as on surfaces. This review is designed to comprehensively explore the many aspects of hydrogel films. It covers the principles of gelation; preparation methods, such as solvent casting, spin coating, and photolithography; and characterization. This review also presents the most common polymers (both natural and synthetic) utilized for the preparation of the hydrogel, the systems, such as nanoparticles, liposomes and hybrid metal–organic structure, that can be used as additives and the aspects related to the biocompatibility of hydrogels. In the second part, this review discusses the potential applications of hydrogel films and the challenges that still need to be overcome. Particular attention is given to biomedical applications, such as drug delivery, wound healing, and tissue engineering, but environmental and agricultural uses are also explored. Finally, this review presents recent examples of real-world applications of hydrogel films and explores the possibility they have for a wide variety of needs. Full article

Despite the emergence of eco-friendly solvents and scalable methods for polymeric membrane fabrication, studies on the impacts of solvent synthesis and manufacturing scale-up have not been conducted. To this end, a life cycle assessment (LCA) was developed with the goal of determining the global environmental and health impacts of producing polysulfone (PSf) membranes with the solvents PolarClean and γ-valerolactone (GVL) via doctor blade extrusion (DBE) and slot die coating (SDC). Along with PolarClean and GVL, dimethylacetamide (DMAc) and N-methyl-2-pyyrolidone (NMP) were included in the LCA as conventional solvents for comparison. The dope solution viscosity had a major influence on the material inventories; to produce a normalized membrane unit on a surface area basis, a larger quantity of PSf-PolarClean-GVL materials was required due to its high viscosity. The life cycle impact assessment found electricity and PolarClean to be major contributing parameters to multiple impact categories during membrane fabrication. The commercial synthesis route of PolarClean selected in this study required hazardous materials derived from petrochemicals, which increased its impact on membrane fabrication. Due to more materials being required to fabricate membranes via SDC to account for tool fluid priming, the PSf-PolarClean-GVL membrane fabricated via SDC exhibited the highest impacts. The amount of electricity and concentration of PolarClean were the most sensitive parameters according to Spearman’s rank coefficient analysis. A scenario analysis in which the regional energy grid was substituted found that using the Swedish grid, which comprises far more renewable technologies than the global and US energy grids, significantly lowered impacts in most categories. Despite the reported eco-friendly benefits of using PolarClean and GVL as alternatives to conventional organic solvents, the results in this study provide a wider perspective of membrane fabrication process impacts, highlighting that upstream impacts can counterbalance the beneficial properties of alternative materials. Full article

With the ongoing electrification of vehicles and the resulting demand for higher power densities, drivetrain requirements are becoming increasingly stringent. Shaft-hub connections are particularly affected in terms of both quantity and design, making innovative solutions necessary. A key factor in meeting these requirements is knowledge of the stress state within the contact area. One promising approach is the application of a thin-film-based sensor system directly onto the shaft surface. This enables, for the first time, the direct measurement of contact pressure in the interface, allowing for more precise connection design. To fully exploit the potential of this sensor technology, its influence on the joining process of shaft-hub connections must be investigated. In this study, cylindrical interference-fits were coated with two thin-film systems relevant to the application, followed by joining tests. The resulting damage was analyzed to derive general recommendations for the joining of coated shaft-hub connections. The results show that shrink-fitting enables damage-free joining, provided specific parameters are met, as confirmed by experimental testing and microscopic examination. This not only preserves the integrity of the sensor system but also establishes the prerequisite for potential in situ measurements, thereby laying the foundation for the feasibility of direct load monitoring during operation. Full article

The rapid dissipation of soft metal lubricants would deteriorate the self-lubricating properties of the coatings at elevated temperatures. In this study, the core-shell structured Mo@Ag@Ni particles were prepared via electroless plating to suppress the rapid dissipation of Ag and facilitate tribochemical reactions at high temperatures. The NiCrAlY-Mo@Ag@Ni composite coating was sprayed on the substrate of Inconel 718 alloy using atmospheric plasma spraying technology. The results of this study show that the structural design of Mo@Ag@Ni can enhance the bonding strength of the particle interface, resulting in a high microhardness of approximately 332.2 HV. During high-temperature friction tests, Mo@Ag@Ni can provide excellent tribological properties by promoting the silver molybdate formation on the worn surface. At 800 °C, the friction coefficient and wear rate are only about 0.32 and 1.58 × 10⁻⁵ mm³N⁻¹m⁻¹, respectively. Moreover, the Ni shell layer can inhibit the rapid diffusion of Ag and provide sufficient Ag₂O to maintain the continuity of Ag₂MoO₄ lubricating film, which endows the coating with a longer lubrication life. Over multi-thermal cycles, the friction coefficient and wear rate constantly maintain at about 0.3 and 2.5 × 10⁻⁵ mm³N⁻¹m⁻¹, respectively. Full article

To meet the growing demand for intelligent surfaces in furniture and interior design, this study developed thermochromic UV coatings for bleached poplar. While conventional UV coatings are valued for their ecofriendliness and rapid curing, their functionality remains limited; integrating thermochromic capability offers a highly promising solution. We examined how the combination of two microcapsule systems (UF@TS and UF@TS-R) influenced the performance of UV coatings on bleached poplar by applying a two-primer/two-topcoat protocol with varied microcapsule loadings to impart color-changing behavior. The effects were then analyzed from multiple perspectives—type, application layer, and concentration gradient—covering optical and mechanical properties as well as thermochromic response. Results indicated that the optimum performance was achieved when UF@TS was incorporated into the UV topcoat and UF@TS-R into the UV primer at specific mass concentrations. The resulting coating delivered temperature-responsive color variation, providing both theoretical and technical support for developing high-value-added UV finishes for wooden furniture and advancing the use of fast-growing timber in high-end applications. Full article