Bulletin of Materials Science最新文献

High-temperature vulcanized silicone rubber (HTV-SiR) insulators degrade outdoors due to their biodegradable nature. To enhance their performance, various fillers are added. This study prepared four HTV-SiR composites using micro/nano-sized silicon dioxide (SiO₂) and micro alumina tri-hydrate (ATH) fillers. The samples were tested for 5000 h in a chamber subjected to electrical and environmental stresses. Post-ageing, the integrity of the composites was assessed through different diagnostic measurements. Results showed tensile strength reductions under positive DC voltage of 32.3, 25.32, 23.56 and 20.12% for samples H₁, H₂, H₃ and H₄, respectively. Sample H₄ exhibited the lowest leakage currents, with values of 5.05 and 5.78 μA for negative and positive DC voltages, respectively. Sample H₄ was hydrophobic attaining HC2 class, while sample H₁ was the least hydrophobic, showing HC4 and HC5 classes under positive and negative DC voltages. Thermogravimetric analysis showed H₄ had the least yield loss, decreasing from 50.1% to 49.2 and 48.9% under positive and negative DC voltages, respectively. FTIR spectroscopy revealed that H₄ maintained the highest integrity in its siloxane backbone (Si–O–Si) connections, with peak reductions of 28% under positive DC stress and 10.1% under negative DC stress. SEM inspection reveals that H₁ and H₂ have significantly degraded, including white powder, cracks, fissures and a blocky structure. After 5000 h of exposure to electrical and environmental stresses, co-filled sample H₄ demonstrated superior anti-ageing performance compared to the other composites. This study underscores the importance of filler selection in enhancing the durability and performance of HTV-SiR insulators in outdoor applications.

Graphene-based materials have garnered significant attention owing to their unique physicochemical properties, exceptionally high surface area, electron mobility, thermal conductivityand mechanical strength. However, graphene has certain limitations viz., irreversible self-agglomeration, low colloidal stability, limited repeatability and non-specificity, which restricts its overall utility. Addressing these issues, functionalization of graphene has been considered as a key strategy that provides augmented properties such as water solubility, biocompatibility, catalytic activity, high surface area, electrical conductivity, and the prevention of agglomeration etc. Thus, various functional groups such as amine, carboxyl and thiol groups have been employed in the fabrication of graphene-based materials for various applications. The present review highlights the synthesis of thiol-functionalized graphene-based materials and their applications in water remediation viz., removal of heavy metal ions and dyes. Additionally, biomedical applications have been addressed in the fields of drug delivery, tumour therapy and biomedical sensors. The present article would help the investigators to develop and explore graphene-based advanced functional materials for addressing real-world issues.

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Manufacturing optimal dressings for chronic wound treatment presents a significant challenge, requiring innovative and precise application techniques tailored to specific treatment needs. This review explores the difficulties associated with chronic wound care and the benefits of hydrogel technology. Ulcers, the most prevalent type of chronic wound, are particularly challenging due to the prolonged healing times. Recent research endeavors have delineated the requisite features of ideal dressings, spurred by advancements in technology, particularly in the realm of hydrogel-based dressings and their integration with promising therapeutic elements for chronic wound care. The study leverages the unique characteristics of hydrogels that emerges as the preeminent dressing choice for fostering the healing of chronic wounds, surpassing alternative dressing options. The potential synergy between hydrogel technology and diverse therapeutic agents holds promise for developing superior hydrogel dressings, exhibiting heightened efficacy in expediting the healing process of chronic wounds.

This study hypothesizes that the separation of the three layers of polypropylene (PP) material of the medical facemasks increases the electrostatic charge (ESC) generated from their triboelectrification by air flow. The ESC increases and enlarges the electric field in front of the facemask to repel viruses. This study examined the effect of the separation of the PP layers by polymeric and metallic spacers on the magnitude of the ESC. The separation by polyurethane (PU) particles showed the highest magnitude of ESC, where PU particles made an air gap between the PP layers. Besides, the negative ESC significantly increased with increasing the air gap between the PP layers. The negative ESC was significantly amplified with the increase in the air gap between the PP layers up to 8 mm at different distances from the outer layer of the tested facemask. Therefore, we suggest that the electric field repels negatively charged viruses. Also, the presence of polyethylene (PE) would generate extra ESC on the sliding surfaces due to its electrostatic property. Using metallic spacers showed lower values of ESC than those generated for PU and PE spacers, as the metallic spacers can conduct ESC generated on the PP layers, and therefore, the total magnitude of ESC decreased. In conclusion, we recommend using PU particles as a spacer in facemasks due to their lighter weight and lower resistance to air flow.

As the use of natural biomaterials has gained more attention, many natural resources—including the tea polyphenol (TP)—have come into focus. Green tea contains a type of natural plant polyphenol, TP, which has excellent properties. These include hydrophobicity, antibacterial, antioxidant, anti-ultraviolet, antiviral, antidiabetic, anti-ageing, anticancer, antitumor and anti-inflammatory properties that others lack. In this review, we first discuss the structure and properties of TP. Furthermore, we examine recently developed TP-based advanced composite materials that incorporate polymers such as polyacrylonitrile, polyaniline, polylactic acid and polyvinyl alcohol, as well as natural materials like chitosan, starch, pomelo peel gelatin and reduced graphene oxide. This review focuses on their structure, properties, and various applications in fields such as food packaging, cosmetics, medicine, health products, and flexible strain sensors, among others.

Crop straw is a kind of renewable resource with great application potential, which has the characteristics of a wide source, abundant reserves and low price. Using straw as a raw material and a hydrothermal process to prepare high-function carbon-based material, it is an economic and green way to promote straw resource utilization. In this article, the influencing factors in the preparation process of straw hydrothermal carbon were reviewed. The influences of process parameters such as straw carbon source, hydrothermal time, hydrothermal temperature and solid–liquid ratio on the structural properties of hydrothermal carbon were emphasized. The regulation of the morphology and structure of carbon by activators such as KOH and KMnO₄ were analysed. At the same time, the application of straw-based hydrothermal carbon in the field of environmental pollution control, catalysis and electrochemistry is summarized. Finally, it is pointed out that the future research should focus on the structure control method, green activation technology of straw-based hydrothermal carbon and the preparation of hydrothermal carbon from mixed straw, and further improve the stability of the porous structure of the hydrothermal carbon and the interference-free in the practical application environment, so as to realize the commercial application of straw-based hydrothermal carbon.

Tungsten oxide (WO₃) has recently gained attention as an electrochromic material for dynamic display technologies, particularly advertising, due to its tunable optical and electrochemical properties. In this study, we compared WO₃ with titanium dioxide (TiO₂) coatings and commercial display films. WO₃ layers with thicknesses of 2, 4, and 6 nm were fabricated using a surfactant-assisted spray pyrolytic method to ensure uniformity and adhesion. TiO₂ coatings served as controls. To confirm the monoclinic phase of WO₃, X-ray diffraction was performed. Optical performance was assessed through UV–Vis–NIR transmission and reflection spectra, while electrochemical behaviour was measured using cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. Durability testing included monitoring transmission and charge insertion/extraction over cycling, alongside environmental stability assessments. An economic evaluation compared Material and operational costs. At 6 nm, TiO₂ films achieved a sharpness score of 70, 75% contrast and 80% colour purity, with transmittance of 55% and colouration efficiency of 0.65 cm²/C. Their switching time was 15 s, and performance degraded significantly after extended cycling, including delamination beyond 50,000 cycles. By contrast, WO₃ films showed higher transmittance (70%), faster switching (12 s), and better colouration efficiency (0.75 cm²/C). They also exhibited more stable charge density retention, improved ion mobility, and stronger current responses in voltammetry. Overall, WO₃ films demonstrated superior optical clarity, faster response, and better durability compared to TiO₂. These findings suggests that WO₃ is a promising, cost-effective material for next-generation electrochromic displays in advertising applications.

This study explores the effect of zinc oxide (ZnO) nanomaterial doping on the electro-optical properties of 5CB-coded nematic liquid crystals and predicts these properties using machine learning algorithms. We produced seven composite structures with varying ZnO doping ratios and measured their electro-optical transmittance. Furthermore, a prediction model using four different machine learning algorithms (k-Nearest Neighbors, Decision Tree, Random Forest, and Extra Trees) was developed, which predicts optical transmittance as a function of voltage and doping ratio. The Extra Trees algorithm demonstrated the best prediction accuracy, achieving an R² value of 91% on the experimental dataset. Subsequently, a new composite with a different doping ratio was then experimentally prepared and measured to validate the model, which was trained on the experimental dataset. This study highlights the utility of machine learning for predicting the electro-optical characteristics of doped liquid crystal structures, resulting in considerable time and resource savings in experimental procedures.

In this article, the theoretical background of MASnBr₃ and Cs₂TiBr₆ was carried out using density functional theory (DFT) by evaluating the electronic properties through the frontier molecular orbital, UV–visible absorption spectra and density of state spectra. Also, a simulation was conducted to optimize a proposed solar cell to improve the performance of perovskite solar cells (PSCs). This cell is composed of six stacked materials, namely FTO/ETL/MASnBr₃/Cs₂TiBr₆/HTL/Au, and features a double active layer consisting of two perovskites, MASnBr₃ and Cs₂TiBr₆. The simulations were carried out using the SCAPS-1D software. Initially, the impact of the electron transport layer (ETL) on the cell’s output parameters was analysed using different materials, such as ZnO, SnO₂, WS₂, PCBM, C60, CdS, TiO₂, CdZnS and ZnSe. Additionally, the effect of the HTL on the photovoltaic parameters of the cell was studied using materials such as MoO₃, CuSCN, NiO, CuSbS₂, Cu₂O, CuI, CuO, PEDOT:PSS, Cs₂TiBr₆ and P3HT. Subsequently, the thickness and doping density of the two active layers were optimized. The thickness and doping density of the ETL and HTL were also optimized. Finally, the effect of different materials on the cell’s performance was examined. The cell demonstrated remarkable performance, achieving parameters such as the open-circuit voltage V_oc = 1,22 V, J_sc = 33,76 mA cm^–2, FF = 89,40% and PCEs = 36,81% for the optimized parameters, including a ZnSe ETL, a MoO₃ HTL with a thickness of 100 nm and a doping density of 10²¹ cm^–3, a thickness of 1000 nm for MASnBr₃ and 400 nm for Cs₂TiBr₆.

Superprismane is a porous, three-dimensional carbon allotrope that combines super-hardness, ductility and low effective-mass charge carriers attributes that make it promising for blue-to-UV optoelectronics and high performance structural applications. In this work, we employ the M-polynomial framework to extract complete closed-form expressions for seven classical Zagreb-type topological indices and their seven multiplicative counterparts for an arbitrary (ptimes k) superprismane lattice. Three-dimensional index surfaces are visualized and benchmarked against two canonical carbon networks ({6.8}^{2};text{D}) and graphite. Using least-squares regression, we demonstrate that the multiplicative inverse-sum index achieves a perfect correlation ((r=1.00)) with shear modulus and an almost perfect correlation ((r=0.99)) with Young’s modulus, outperforming all other descriptors. These results show that M-polynomial-derived indices provide a rapid, inexpensive alternative to density-functional calculations for predicting bulk mechanical properties, enabling high-throughput computational screening of novel carbon materials. The study closes a gap in the literature by delivering the first comprehensive suite of additive and multiplicative indices for a three-dimensional porous carbon network and establishes a foundation for data-driven design of advanced allotropes.