Search Results (1,999)

The present work aims to evaluate the electrochemical behaviour of 316L stainless steel flat sheets both uncoated and coated with an organic–inorganic silane hybrid formulation based on TEOS (tetraethyl orthosilicate) and TMES (Trimethylethoxysilane) as silane precursors. The influence of the modification of the silane-based layer by the incorporation of 3-aminopropyl trimethoxysilane (APS) doped TiO₂ (N-TiO₂) on the pitting properties of the coatings has been studied. The obtained protective films have been characterized from compositional (EDX), morphological (FE-SEM), and electrochemical (corrosion) points of view. Concerning their morphology, the coatings look continuous and smooth. Regarding their electrochemical properties, the results show that the application of the developed N-TiO₂-containing silane coatings extends the passive potential range of 316L stainless steel in simulated body fluid; thus, it improves the pitting resistance of the substrate. Full article

Phosphate coatings were obtained by cold method from solutions based on Mazev Salt (containing Mn(H₂PO₄)₂∙2H₂O and iron phosphates). Metal nitrates and nitrites were introduced into solutions as accelerators of the phosphating process. To obtain green and blue phosphate coatings, procyon olive green and methylene blue dyes (8 g/L) were added into the solutions. Colored phosphate coatings are deposited unevenly on the steel surface. The thickness of the modified phosphate films was estimated from SEM images of the cross-section samples and determined to be 3–4 microns. Colored phosphate coatings are fine-grained with a grain size of 170–190 nm, which was determined using an atomic force microscope. Phosphate films continue to exhibit protective properties when heated to 100 °C. With a further increase in temperature, the protective ability of the film is significantly reduced. Colored phosphate films have a low coefficient of friction (0.1–0.15). The breakdown voltage of colored phosphate coatings is 180–200 V, which characterizes low electrical insulation ability. Based on the established properties, colored phosphate coatings can be used as protective and decorative. Full article

Background: Dry eye disease (DED) is characterized by tear film instability and a hyperosmolar ocular surface, which significantly impacts ocular health. Artificial tear solutions (ATSs) have been effective frontline treatments for DED, yet current commercially available products often provide only temporary relief, necessitating frequent daily administration. Significant efforts have been made to develop next-generation ATSs that can provide prolonged protective effects for DED. High-molecular-weight sodium hyaluronate (HA) is more commonly used in multi-dose preservative ATSs due to its longer chain lengths and rheological properties that can provide an enhanced retention time and clinical comfort and effects. The current methods to evaluate ATSs have largely focused on human biocompatibility and rheological testing and often overlook the dynamic nature of cellular phenotypes or the protective mechanisms at a cellular level. Therefore, this study developed novel in vitro mammalian cell assays involving human corneal epithelial cells (HCECs) to comprehensively assess ATSs with HA for biocompatibility and efficacy. Methods: We evaluated cellular viability across varying severities in two distinct DED models: desiccation and hyperosmotic stress. Simultaneously, time-lapse imaging coupled with computational image analyses quantified subtle, yet significant, cellular morphological changes under these stress condition. Results: Our assays revealed that ATSs provide significant, yet varying, protection against mild, medium, and harsh desiccation stress, as well as hyperosmotic conditions. This study also made a key insight that was the observation that DED conditions induce drastic HCEC morphological changes, including significant cellular monolayer breakage, which were effectively mitigated by the ATS products used in this work. Conclusions: The assays presented here provide a robust standard for ATS testing, ultimately guiding the selection of more effective next-generation therapies and aiding in a greater understanding of DED pathogenesis. Full article

Vanadium dioxide (VO₂) is a highly promising material for infrared laser protection due to the pronounced optical switching effect during its metal–insulator transition (MIT). However, due to the relatively high MIT temperature of VO₂ and the low transmittance contrast before and after the MIT, practical applications face challenges in modulation depth and response time. In this study, we address these issues using a wafer-scale VO₂/GaN/Al₂O₃ heterostructure fabricated by oxide molecular beam epitaxy. The conductive GaN interlayer enables local Joule heating of the VO₂ film, permitting direct control of the MIT via an external bias with a threshold of 4.7 V. This structure exhibits a substantial resistance change of four orders of magnitude and enables adaptive limiting of a 3.7 μm laser, reducing transmittance from 60% to 10%. Our work demonstrates a practical, wafer-scale laser-protection device and introduces a pre-excitation strategy via external biasing to enhance response performance. Full article

Heat damage is a common phenomenon that often occurs when drying and straightening hair. After heat damage, the hydrophobic barrier on the hair’s surface becomes disrupted, thereby altering the hair’s hydrophilicity. Meanwhile, during the process of heat damage, the rupture of the hair’s cuticles causes the hair to become dry and rough, with a decrease in gloss and a decline in mechanical properties. This study utilized epoxy silane and hydrolyzed wool keratin to synthesize a thermally responsive organic silicon-modified keratin (OSK) to prevent hair from heat damage. OSK was synthesized from epoxy silane and hydrolyzed keratin, with yield determined by quantifying free amino groups. Its hair-care performance was evaluated through assessments of hair surface morphology, mechanical properties, and optical gloss, and by combing test and contact angle measurements. Mechanisms underlying surface hydrophobicity and hair scale protection were investigated using FTIR, XPS, and DSC. Specific performance parameters were evaluated using a single-fiber strength tester and a multifunctional hair-testing instrument. FTIR confirmed successful covalent grafting, with synthesis optimized to a 90.67% yield. OSK forms a protective film on hair surfaces, verified by SEM, XPS, and TEM, restoring damaged hair hydrophobicity to a 117° contact angle and enhancing thermal protection to 136° upon heating. Beyond hydrophobic-barrier restoration, OSK improved hair gloss by 30.26% and reduced frizz by 39.33%, while restoring the key performance of virgin hair. It also provides exceptional water-repellency protection and sensory enhancement. Under thermal stress, the protective film mechanically increased tensile strength by 6.58% and yield zone tensile force by 4.65%. This article demonstrates that OSK is an effective heat-sensitive agent. When damaged by heat sources such as hair dryers, it will form a protective film on the surface of the hair, thereby protecting the surface properties of the hair. Full article

Background/Objectives: Oral mucosal wounds are frequently encountered in daily dental practice and are often difficult to manage because of continuous exposure to saliva, mastication, and mechanical irritation. This technical note describes the clinical practicality of an oral liquid bandage (ORAPLA) as a film-forming protective barrier for traumatic and surgical oral mucosal wounds. Methods: ORAPLA was applied in four clinical scenarios: a traumatic lip bite injury, a postoperative mucosal defect following leukoplakia excision, a biopsy wound for suspected oral squamous cell carcinoma (OSCC), and aphthous stomatitis. Clinical observations included patient-reported symptom relief, film retention, and the clinical appearance of epithelialization at follow-up (1–2 weeks). Results: In all cases, ORAPLA formed a thin protective film immediately after application and was typically observed to remain on the wound surface for approximately 5–6 h under routine daily activities. Patients reported prompt subjective pain relief, and no adverse events were observed. Epithelialization proceeded without clinically evident secondary infection during the follow-up period. Conclusions: In this small descriptive case series, ORAPLA was feasible to apply, well tolerated, and provided temporary mechanical protection with immediate subjective comfort. Controlled studies using standardized outcome measures are warranted. Full article

Tree peony (Paeonia sect. Moutan) is one of the most important traditional ornamental woody flowers in China. However, its cultivation is often challenged by intense light and high temperatures during summer, leading to severe photo-oxidative damage and leaf senescence. In this study, we investigated the protective effects of polyolefin (PO) film on potted tree peony leaves under summer intense light and high temperature stress. Using tree peony ‘Luoyanghong’ as experimental material, we systematically compared the effects of two controls under natural light (CK1 and CK2, housed in separate greenhouses), single-layer PO film (PO1), and double-layer PO film (PO2) treatments. Microenvironment monitoring showed that single-layer and double-layer PO films reduced light intensity by 21% and 49%, respectively, while having limited effects on temperature. Morphological and physiological analyses indicated that PO film treatments effectively alleviated leaf yellowing and withering, maintained normal physiological morphology, and increased chlorophyll (Chl) and carotenoid (Car) content. The net photosynthetic rates of PO1 and PO2 plants were 18–36% higher than those of the control groups (CK1 and CK2). Evans blue and NBT staining revealed that PO film reduced cellular damage and reactive oxygen species (ROS) accumulation, while decreasing malondialdehyde (MDA) levels and increasing catalase (CAT) activity. Furthermore, qRT-PCR results showed that stress-responsive genes (Hsp70, Hsp90, and ATG5) and photosynthetic genes (RbcS and RbcL) were upregulated under PO film treatment. Principal component analysis (PCA) indicated that high light intensity, rather than temperature, was the primary factor causing leaf damage in potted tree peonies. The results show that PO film is an effective and low-cost agronomic measure, which can alleviate the intense light stress under high temperature conditions, relieve photo-oxidative damage, maintain photosynthetic performance, and increase the survival rate of potted tree peonies in summer. Full article

In electric vehicle (EV) drivetrains, lubricant films must not only mitigate friction and wear but also manage stray currents to safely dissipate stray charge and avoid micro-arcing. This study directly compares how a conventional antiwear additive (ZDDP) and a long-chain, ashless, sulfur-free phosphite ester (Duraphos AP240L) manage this balance under current-carrying boundary lubrication conditions. Reciprocating steel-on-steel tests were conducted at fixed load and speed with applied current densities of 0, 0.02, and 42.4 A/cm². Friction and four-probe electrical contact resistance (ECR) were measured in situ, and impedance of tribofilms was measured over a 1–10⁵ Hz range after friction test. In the presence of ZDDP, ECR initially increased and then decreased to a value that was as low as the initial direct contact of two solid surfaces or even lower sometimes. During the initial stage with high ECR, a well-defined impedance semicircle was observed in the Nyquist plot; after forming the tribofilm with low ECR, frequency dependence of impedance could not be measured due to the very low resistance. The decrease in ECR suggested a structural evolution of the anti-wear film on the substrate. However, post-test wear analysis indicated that the formation of this film was accompanied by tribochemical polishing of the countersurface and sometimes pitting of the substrate, which may have been due to localized electrical discharge producing trenches deeper than ~0.5 µm; in additive-free base oil, wear was dominated by ploughing with micro-cutting of the substrate. In contrast, AP240L performed better in terms of friction and wear, showing a remarkable ~30% lower coefficient of friction, while the overall cycle dependence of ECR was similar to the ZDDP case. AP240L showed negligible boundary film controlled wear producing a shallow, smooth track (depth < 0.2 µm) during the friction test, and there was no sign of electrical arc damage. These findings support long-chain, ashless, sulfur-free phosphite esters as promising candidates for EV boundary lubrication where both mechanical and electrical protection are required. Full article

The optical properties of greenhouse cover materials play a critical role in controlling the internal light environment, directly affecting photosynthetic performance and crop productivity. This study evaluates the impact of a high photosynthetically active radiation (PAR) transmittance and high-light-diffusivity polyethylene film on the microclimate, photosynthetic activity, yield, and disease incidence of cucumber (Cucumis sativus L.) crops grown in a Mediterranean passive solar greenhouse. Trials were conducted over two consecutive autumn–winter seasons using a multi-span greenhouse divided into two sectors: one covered with an experimental high-transmittance film and the other with a standard commercial plastic. The experimental cover increased PAR transmission by 8.7% and 11.6% at canopy level in the first and second seasons, respectively, leading to improvements in leaf-level net photosynthesis of 9.3% and 17.9%. These effects contributed to yield increases of 5.0% and 17.3% in the respective seasons. The internal air temperature rose by up to 1.3 °C without exceeding critical thresholds, and no significant differences were observed in plant morphology or fruit quality between treatments. Additionally, the experimental film reduced the incidence of major fungal diseases, particularly under higher disease pressure conditions. The use of high-PAR-transmittance films enhances radiation use efficiency and crop performance in resource-limited environments without increasing energy inputs. This approach offers a sustainable, low-cost strategy to improve yield and disease resilience in protected cropping systems under passive climate control. Full article

Ultra-high-molecular-weight polyethylene (UHMWPE) thin films are considered promising shielding materials against hypervelocity microparticle impacts in space environments. In this study, a finite element-smoothed particle hydrodynamics (FEM-SPH) adaptive coupling simulation method was developed to reveal the damage mechanisms of UHMWPE films impacted by alumina (Al₂O₃) particles with a diameter of 10 μm. A 100 μm thick single-layer UHMWPE film was subjected to normal impacts at velocities ranging from 1 to 30 km/s. The morphology and characteristics of craters formed on the film surface were analyzed, revealing the velocity-dependent transition from plastic deformation to complete perforation. At 10 km/s, additional oblique impact simulations at 30°, 45°, 60° and 75° were performed to assess the effect of impact angle on damage morphology. Furthermore, the damage evolution in double-layer UHMWPE films was examined under impact velocities of 5, 10, 15, 20 and 25 km/s, showing enhanced protective performance compared to single-layer films. Finally, the critical influence parameters for UHMWPE failure were discussed, providing criteria for evaluating the shielding limits. This work offers computational methods and predictive tools for assessing hypervelocity microparticle impact and contributes to the structural protection design of spacecraft operating in the harsh space environment. Full article

This study focuses on sulfuric acid-anodized films formed on 2A12 and 6061 aluminum alloys, in which the corrosion behavior of the oxide films under different film thicknesses, sealing methods, and defect states was investigated through neutral salt spray testing combined with surface morphology characterization and XRD analysis. The results indicate that the corrosion resistance of anodic oxide films is positively correlated with film thickness, while the anodized film on 2A12 aluminum alloy contains more cracks than that on 6061, which can readily serve as long-term corrosion initiation sites. Although the corrosion products of both alloys are identified as Al₂O₃ and AlO(OH), the oxide films on 6061 aluminum alloy exhibit higher compactness than those on 2A12 at all investigated thicknesses, resulting in superior resistance to neutral salt spray corrosion, and both sealing methods provide effective protection for the 6061 aluminum alloy substrate. This study provides experimental and theoretical references for the development and application of anodizing processes for aluminum alloys in chloride-containing marine environments. Full article

We propose a 1D photonic crystal with nonlinear graphene–spacer–graphene truncation, which enables a tunable, non-monotonic, and intensity-dependent transmission response. By employing synthetic geometrical space to obtain Fermi arc states, the structure is designed to support a real-space topologically protected Tamm plasmon polariton, revealing an intensity-dependent transmission peak within the THz spectral range. As such, the proposed thin-film structure may serve as a nonlinear DBR element that can be integrated into a laser cavity to provide intensity-selective feedback, thereby facilitating controllable pulse shaping and enabling passive pulse formation mechanisms such as mode-locking or Q-switching. Due to its topological robustness, spectral scalability, and electrical tunability via graphene biasing, the platform provides a new route toward compact, reconfigurable nonlinear reflectors for efficient and controllable laser pulse generation, thereby extending the functionality of conventional saturable absorbers and semiconductor DBRs. Full article

In this work, we report a protective encapsulation intended as the final coating layer on solar cells. The formulation consists of polylactic (PLA)-based resin, modified with hexadecyltrimethoxysilane (HDTMS), epoxidized polybutadiene (EPB), and benzotriazole as a UV absorber with approximate weight fractions ranging from 20 to 60 wt% for PLA, 30–80 wt% for solvents (toluene and chloroform), and 0–5 wt% for HDTM, EPB, and benzotriazole with percentages 54.2%, 29.2%, and 16.7%, respectively. The encapsulating material, due to its insulating nature and high optical transparency, surpasses that of ethylene–vinyl acetate (EVA), as demonstrated in this study. To assess the protective effect of the developed formulation, the study focused on applying the modified PLA resin onto isolated methylammonium lead iodide (MAPI) perovskite films on glass substrates. The samples were prepared as isolated MAPI absorbers to specifically assess the intrinsic contribution of the dual encapsulation configuration at its real position in a complete solar cell stack, demonstrating that even this unoptimized perovskite film exhibits remarkable stability and excellent structural and optical retention over two months under the protective scheme (86% of its initial structural stability, as quantified from integrated XRD peak intensities, and 68% of its initial optical absorbance, determined from the integrated UV–Vis spectra), whereas the uncoated films showed significant degradation. Although MAPI was selected as a model system due to its well-known environmental instability, the proposed encapsulation material and methodology are not limited to this architecture and can, in principle, be applied to various photovoltaic technologies. These findings demonstrate the strong potential of the polylactic-based resin as an effective environmental barrier for solar cells and provide a solid foundation for future full-device integration studies. Full article

Due to its amphiphilicity, the natural fibrous structural protein, silk fibroin (SF), can adsorb at the oil/water interface, form protective viscoelastic layers, and stabilize emulsions. Biocompatible SF-stabilized emulsions can be used in different fields of cosmetics, food, drug delivery, and biomedicine. Depending on the silk processing method, various emulsion types can be obtained, such as film-stabilized emulsions stabilized by SF molecules and Pickering emulsions stabilized by nanostructured SF or SF particles. Nanostructured SF and SF particles, with β-sheet dominated secondary structures, can overcome the drawback of SF molecules with unstable conformation transition during application, and thus endow higher emulsion stability than SF molecules. The emulsions stabilized by SF nanoparticles can endure heat and high ionic strength, while the emulsions stabilized by SF nanofibers show superior stability at high temperature, high salinity, and low pH due to the strong interfacial entangled nanofiber networks. In this review, the recent progress in research on SF-stabilized emulsions is summarized and generalized, including a systematic comparison of the stabilization mechanisms for different SF morphologies, and the influences of the emulsion fabrication technique, component type and proportions, and environmental conditions on the microstructures and properties of SF-stabilized emulsions. Understanding the stabilization mechanism and factors influencing the emulsion stability is of great significance for the design, preparation and application of SF-stabilized emulsions. Full article

Sloping cropland on the Loess Plateau faces severe challenges from soil organic carbon (SOC) depletion and structural instability due to erosion and intensive tillage. Although mulching can enhance SOC sequestration, its long-term effects on the spatial distribution of SOC and aggregates across slopes remain unclear. A 15-year field experiment evaluated five practices—conventional tillage (T), no tillage (NT), straw mulching (SM), plastic film mulching (PM), and ridge–furrow plastic film mulching (RPM)—on SOC storage, aggregate stability, and their variation with different slope positions. Compared to T, all mulching treatments significantly increased SOC concentration by 4.19% to 83.48% in the 0–30 cm layer. SM and RPM notably increased macro-aggregates (>2 mm) and their associated SOC (24.04–56.49% higher than T) by adding organic matter and optimizing micro-topography. Different slope positions strongly influenced SOC redistribution: lower slopes accumulated more SOC than upper slopes due to erosion–deposition processes. Mulching reduced SOC spatial variability and minimized differences between slope positions. Although mulching increased cumulative SOC mineralization compared to T, the long-term net SOC gain was positive, driven by improved aggregate protection and reduced erosion. SM and RPM are recommended for sustainable slope farmland management due to their dual benefits in enhancing carbon sinks and soil stability. This study offers practical strategies for improving soil health and SOC sequestration in vulnerable sloping landscapes. Full article