Journal of Materials Science最新文献

Developing of lightweight materials with extremely low thermal expansion is crucial across various sectors. While Invar exhibits a coefficient of thermal expansion (CTE) below 3 × 10⁻⁶ °C⁻¹, its heavy nature limits its applicability in electric vehicles and aerospace fields. The present study introduces Al6061/SiC composites produced by the nitrogen-induced self-forming aluminum composite (NISFAC) process, wherein CTE is successfully tailored down to an unprecedented value of 2.12 × 10⁻⁶ °C⁻¹ at 100 °C by changing the volume fraction of SiC from 0 to 65%. In-situ AlN, formed at the interface between Al6061 and SiC particles during the NISFAC process, plays a crucial role in minimizing the thermal expansion of the composites by improving crystallographic match and adhesion between SiC particles and the Al matrix.

All-inorganic perovskite solar cells (AI-PSCs) are emerging as a promising alternative to organic–inorganic hybrid perovskite solar cells (OIH-PSCs), primarily due to their superior stability and enhanced tolerance to higher temperatures. Despite being a relatively recent focus of research within the perovskite solar cell (PSC) domain, AI-PSCs have demonstrated significant potential, notably in terms of efficiency and durability. However, the power conversion efficiency (PCE) of AI-PSCs, while impressive, has yet to surpass that of OIH-PSCs, highlighting a critical area for further improvement. To date, the PCE of AI-PSCs has reached over 21%, with a rapidly growing body of research contributing to this advancement. This review paper comprehensively summarizes the critical aspects influencing AI-PSC performance, including the fundamentals of crystal structure and its impact on stability, device architecture enhancements to boost PCE, and the role of halide composition in optimizing both stability and efficiency. Specifically, we delve into how halide compositions affect the growth and stability of perovskite at both bulk and interface levels, leading to improved charge carrier dynamics. Finally, we discuss the future outlook and potential of AI-PSCs, outlining a clear path towards their commercial viability.

In the current study, a HA/TiO₂ composite coating is effectively fabricated on a Ti-13Nb-13Zr alloy using the plasma electrolytic oxidation (PEO) technique. Electrolytes with different Ca/P contents are selected to study the evolution of phase composition and microstructure of PEO coating. The relationship between Ca/P contents and the wear resistance and corrosion resistance of the coatings are evaluated. The Ca/P-30 g coating exhibits the best performance with Ca/P≈1.66. The average thickness and roughness of the coating manufactured by this system are about 159 µm and 1.591 µm. The HA/TiO₂ coatings akin to honeycomb have analogous pore size and uniform distribution, and the phase composition is mainly anatase. Compared with the substrate, the corrosion current density decreases by 19.65% and the corrosion potential increases by 0.805 V. The findings suggest that suitable Ca/P can promote the formation of HA, which is associated with the nucleation and growth rate of HA crystal. Furthermore, the formation mechanism of HA is simulated and the effect of Ca/P on the growth of HA is discussed. The process aims to reduce the allergic and toxic reactions caused by Ti-13Nb-13Zr implants, which is of great significance for increasing the service life of titanium alloy implants and reducing the implant failure.

Using chemical-based ethylene scavengers for climacteric fruits and vegetable preservation and shelf-life extension has adverse effects on human health and the environment. Technology research has gained popularity using sustainable and non-toxic materials to overcome traditional ethylene removal and freshness maintenance challenges. Clay, a naturally occurring mineral with high availability, low cost, and unique functional properties, has been investigated over the years. It has shown potential as an effective and safe candidate for fresh produce preservation due to its non-toxicity and ethylene adsorption capacity. Recently, clay-based or clay-modified ethylene scavengers have drawn attention due to their high specific surface area, ease of modification, and efficiency as an active packaging material. The review paper aims to highlight the key details of clay-based ethylene scavengers, illustrating its mechanism of ethylene removal, classification of clay, a factor that regulates ethylene removal capacity, and the form and application of clay used for fresh produce preservation. The review also addresses the legal and regulatory aspects, challenges, and future directions of clay-based ethylene scavengers. Clay-based films, sachets, pads, and pellet covers have been used for ethylene control and show promising approaches for sustainable food packaging. Clay-specific surface area, pore volume, storage temperature, and humidity significantly affect the ethylene removal capacity. The review is significant for promoting the development and expanding the industrial application of clay-based ethylene scavengers for fresh produce packaging.

GRAPHICAL ABSTRACT

In this work, two binary carbon-based composite phase change materials consisting of paraffin (PW), lauric acid (LA) and tetradecanol (TD) were prepared. Delignified wood flour (DWF) was obtained through treatment with a mixture of NaOH and Na₂SO₃. The pore volumes of DWF and wood flour (WF) are 0.01049 and 0.008955 cm³/g, respectively, and the pore volume of DWF increased by 17.16%. The adsorption capacity of DWF for LA-PW and LA-TD reaches 50%, which is 10% higher than the adsorption capacity of WF for LA-PW and LA-TD. The thermal conductivities of LA-PW/DWF and LA-TD/DWF are 0.3762 and 0.3580 W/m k, respectively. The phase transition temperatures of LA-PW/DWF and LA-TD/DWF are 40.86 ℃ and 19.68 ℃, respectively. The phase transition latent heat for LA-PW/DWF and LA-TD/DWF is 88.86 J/g and 62.31 J/g, which are 33.61% and 26.18% higher than those of LA-PW/WF and LA-TD/WF, respectively. After 200 cycles, the maximum value of the change rate in phase transition temperature for LA-PW/DWF and LA-TD/DWF is less than 2.64%, and the peak shape remains consistent before and after the cycle, which have good thermal stability.

Graphical Abstract

The adsorption capacity of DWF obtained by alkali delignification of wood flour was enhanced. LA-PW and LA-TD were uniformly adsorbed in the pore structure of DWF by capillary force and surface tension. LA-PW/DWF and LA-TD/DWF have high phase transition latent heat and good thermal and stability.

Both the nano-modified multimodal and conventional Cr₃C₂-NiCr coatings were fabricated by laser cladding (LC) on a CuCrZr alloy substrate with a stainless steel transition layer. The study investigated the microstructural evolution of the coatings during the LC process. The effect of the stainless steel transition layer between the substrate and coatings on microstructure, microhardness, and wear resistance was discussed. Many aggregates formed by the aggregation of micron or large-size submicron particles contain many cavities, which are filled by small-size or nano-ceramic particles during the laser cladding process to improve the density of the coatings and properties. Different from other LC coatings, only micro-melting occurred in the bonding zone between the coatings and transition layer, but no apparent melting phenomenon appeared, which may be due to the high content of Cr₃C₂ ceramic phase and low content of NiCr adhesive phase in the coatings. The Cr₃C₂-NiCr coatings, transition layer, and copper (Cu) substrate are seamlessly integrated and compatible, ensuring effective interface formation without any discernible cracks. The nanostructure multimodal Cr₃C₂-NiCr coating showed significantly higher average microhardness values of 1357 HV_0.3 than conventional Cr₃C₂-NiCr, 1184 HV_0.3. Furthermore, careful parameter selection led to outstanding wear-resistant nano-modified multimodal Cr₃C₂-NiCr, paving the way for future industrial applications.

Graphical abstract

An effective elimination of pharmaceutical pollutants offers a huge challenge for the conventional wastewater treatment system. In this study, the core–shell and reverse core–shell structures using zeolitic imidazole frameworks (ZIF-8 and ZIF-67) were prepared. Structural and morphological analyses were confirmed using XRD, RAMAN, XPS, and TEM techniques. The reverse core–shell structure (ZIF-8@ZIF-67) was explored as a photocatalyst for the efficient degradation of multiple classic anticancer drugs, including capecitabine (CAP) and 5-fluorouracil (5-FU), under visible light. This structure benefits from its unique design, offering a larger surface area and the intrinsic characteristics of each component. The synergistic interactions provide more accessible reactive sites, facilitate the diffusion of contaminants, enhance charge separation ability, and improve light utilization. Significantly, the optimized ZIF-8@ZIF-67 achieved a 98.4% removal rate of capecitabine (CAP) and a 97.4% removal rate of 5-fluorouracil (5-FU) under visible light in 120 min and 150 min, respectively, via the photo-reduction pathway, demonstrating superior photocatalytic performance. Various functional parameters, including catalyst dosage and pH effect, were thoroughly examined. Additionally, ZIF-8@ZIF-67 was recycled for five runs, with only a 10.8% of CAP decrease in degradation efficiency due to catalyst loss during washing. Therefore, ZIF-8@ZIF-67 not only exhibits superior photocatalytic performance but also maintains significant reusability. The findings of this study indicate that ZIF-8@ZIF-67 is a promising candidate for the effective removal of pharmaceutical pollutants from wastewater sources.

Graphical Abstract

Visible Light-Induced Photocatalytic Degradation of Anticancer Drugs via Zeolitic Imidazole Framework (ZIF-8@ZIF-67): Mechanistic Insights

Al–Ti–C/7075 aluminum matrix composites (referred to as 7075-ATC) containing uniformly distributed TiC particles and traces of TiAl₃ particles were produced by introducing 2 wt. % Al–Ti–C master alloy through stir casting. Isothermal thermal compression behavior at 300 °C–450 °C and 0.001 s⁻¹ to 1 s⁻¹ strain rates was studied in a Gleeble-3800 thermal simulation tester. Peak stress is influenced by deformation temperature and strain rate, reaching its maximum at low temperatures and high strain rates. The activation energy of the final thermal deformation is 150.11 kJ/mol, attributed to particle reinforcement. A sinusoidal hyperbolic Eigen structure equation for composites considering strain compensation is developed to describe the rheological stresses in composites. Dynamic recrystallization at 450 °C and a strain rate of 0.001 s⁻¹ enhances composite molding properties. After hot compression, composites exhibit higher activation energy (Q) than cast 7075 and in situ particle-reinforced 7075 due to the obstruction of dislocations by the particles, grain refinement, and pinning effect on the grains. Based on the experimental results, an intrinsic model considering strain compensation was developed to accurately predict the thermal deformation behavior. EBSD results indicated that dynamic softening primarily occurred through dynamic restitution and partial recrystallization. The efficiency of softening peaked at 39% under a strain of 0.6, deformation temperatures between 350 °C and 450 °C, and strain rates ranging from 0.0009 s⁻¹ to 0.0111 s⁻¹.

The present study investigates the formation mechanism of black spot defects on the surface of industrial continuously hot-dip galvanized Zn-2Al-1.5Mg coatings. Electrochemical experiments and neutral salt spray tests are conducted to study the corrosion resistance of the black spot defects and their influence on the corrosion mechanism of the coatings. The results show that the enrichment of Mg elements within the coating is the fundamental cause of the formation of this defect. The enrichment of Mg elements leads to a reduction in the size of primary Zn, an increase in the proportion of eutectic structures and the MgZn₂ within the defective coatings. Consequently, the defective coatings exhibit the higher surface hardness and, after skin pass rolling, display the different reflective properties compared to surrounding coatings. The black spots feature is attributed to the formation of oxide film containing MgO. The electrochemical test results indicate that black spot defect exhibits enhanced corrosion resistance due to the lower Volta potential difference (VPD) between each phase on its surface. Moreover, the fine and dispersed cathodes not only avoid the occurrence of extremely pH sites, but also facilitate the formation of uniform distributed corrosion products with high protective ability. In the 600-h neutral salt spray experiments, Zn-2Al-1.5Mg coatings with black spot defects exhibit enhanced corrosion resistance, which is attributed to the Mg enrichment delaying the decomposition of highly protective corrosion products.