Materials Letters最新文献

Solar energy, as a crucial green energy source, attracted significant attention. Phase change materials (PCMs) addressed the intermittency issue by storing and releasing latent heat. This study innovatively combined carbon fibers (CFs), phenolic resin, polyethylene glycol (PEG), and multi-walled carbon nanotubes (MWCNTs) to create high-loading (>86 %) and high-enthalpy composite CF-based phase change materials (CFPCMs), with melting and freezing enthalpies of 156.6 J/g and 148.6 J/g. CFPCMs demonstrated excellent photothermal and electrothermal properties. The lightweight, porous CFs structure stabilized the PCMs matrix, enhancing its performance while facilitating the reuse of waste CFs products, thus contributing to environmental protection.

This study evaluated the effectiveness of electrospun cellulose acetate fibers (CAFs) containing oleic acid (OA) for corrosion inhibition on carbon steel in chloride-rich environments. By varying the OA content, CAFs of different thicknesses were produced. Potentiodynamic polarization showed that steel coated with OA-containing CAFs had enhanced corrosion resistance, with higher corrosion potential (E_corr) and lower corrosion current density (i_corr). The electrochemical impedance spectroscopy (EIS) results for the dip-coated sample showed an impedance increase of approximately 20× (from 2 to 40 kΩ cm²), and a capacitance reduction from 10⁻⁶ to 10⁻⁸ F cm⁻², compared to the untreated sample. The protective effect remained even after 48 h of exposure. These findings suggest CAFs as effective carriers for delivering OA inhibitors, offering a promising solution for corrosion mitigation in saline environments.

Through hot compression experiments under different deformation conditions (0.1 s⁻¹ at 900 °C/1050 °C/1200 °C), the effect of coordinated deformation on microstructure evolution was studied, and the influence of different initial microstructures on corrosion performance was subsequently investigated. As a result, strain preferentially concentrated in 20#, resulting in dynamic recrystallization (DRX). Subsequently, grain refinement and DRX occurred in 316L. Additionally, the farther from the interface, the weaker the coordinated deformation effect. Compared to only 316L, the 316L in composite pipes has higher density of dislocations and low-angle grain boundaries. Corrosion resistance is related to the microstructure after coordinated deformation, decreasing with the increase in dislocation density, low-angle grain boundaries, and recrystallized grain size. At 1200 °C, the effect of coordinated deformation on 316L is significantly reduced. The passivation film resistance is 2.14 × 10⁶ Ω·cm², similar to that of only 316L. Therefore, appropriately increasing the hot rolling temperature and the thickness of 316L in the billet can reduce the effect of coordinated deformation on the DRX of 316L, thereby maintaining the pitting corrosion resistance of 316L.

This study explores the synthesis of silver nanoparticles (AgNPs) using untreated whey as a green approach, followed by their integration into biodegradable gelatin films for potential applications in antimicrobial packaging. UV–visible spectroscopy and scanning electron microscopy confirm the successful synthesis of AgNPs, which are seamlessly incorporated into flexible and semi-transparent gelatin films. Comparing films with and without AgNPs, subtle changes are observed in UV–visible and Fourier-transform infrared spectra that are attributed to the low AgNP concentrations. However, the resulting films with AgNPs exhibit effective bactericidal efficacy against E. coli. Moreover, soil burial tests demonstrate significant biodegradability, with up to 80% mass loss within two weeks, showing comparable rates between films with and without AgNPs. These results show the prospects of whey-derived AgNPs in the development of sustainable, antimicrobial biodegradable films with potential applications in various industries.

We report pulsed laser emission using fluorescein combined with avidin as an active medium matrix in a Littrow-like configuration system. The study covers testing several solvents and a range of excitation energies, aiming to get the narrowest bandwidth for stable peak emission wavelength. Initially, for 4 mM of fluorescein in 1:1 mixture of methanol-NSS, and excited with 20.80mJ of energy, a laser mission of 4.38 nm bandwidth is achieved. Then, different concentrations of thiolated avidin are mixed in the active medium, causing related red-shifts over the initial emission band. Substantial spectral changes are observed down to 0.3 μM of avidin, making apparent the stability conditions for this sort of laser system to work out as a biosensor.

In this paper, choline chloride, acrylamide and urea were used to prepare deep eutectic solvent (DES), and CS and N-CNTs were used as fillers to prepare composite hydrogels through in-situ polymerization. Using FTIR and SEM characterization analysis, the results showed that the pressure sensitivity and conductivity of the composite hydrogel were significantly improved after adding CS and N-CNTs. When the filler content reaches the highest level, the pressure sensitivity increases by 13 times and the conductivity reaches 2.05 mS/cm, which is 14.7 times that of the hydrogel without filler. This study provides a preparation method for composite hydrogels with excellent conductive properties and pressure sensitivity.

In this study, the green synthesis of silver nanoparticle (Ag) decorated reduced graphene oxide (RGO) nanohybrid using Terminalia Arjuna bark extract was reported for the first time. As-synthesized Ag/RGO nanohybrid was used as a highly active and recyclable green catalyst for the reduction of harmful nitroaromatics (p-nitrophenol and p-nitroaniline) and azo dyes (methylene blue, methyl orange and Congo red) with significant efficiency. The catalytic reduction of the nitroaromatics and azo dyes followed pseudo-unimolecular kinetics in the present study. Notably, the Ag/RGO nanohybrid exhibited excellent reusability and stability till five recycle runs. The present study can provide new insights into the growing interest of low-cost and environmentally benign methods for nanomaterial synthesis towards environmental remediation applications.

It remains challenging for conventional materials to achieve cartilage-mimetic structures and properties. In this work, a sandwich hydrogel was reported to overcome this issue. Due to the introduction of soy lecithin (SL) at the top layer, the friction coefficient was 0.02. On account of the multiple linkages from polyvinyl alcohol (PVA), chitosan (CS), and grape seed protein (GSP) in the intermediate layer, the compressive strength was 42 MPa. Owing to the existence of GSP and tannic acid (TA) in the bottom layer, the hydrogel exhibited excellent adhesion onto various materials. Meanwhile, the volume and mechanical performances were almost constant after soaking in simulated synovial fluid for a week. Furthermore, the abundant phenols of GSP empowered remarkable antioxidant capacity. Because of biocompatible materials, the cell viability was 100 %. All of these merits make it an ideal substitute for cartilage.

The influence of electromagnetic waves on the interfacial tension of cobalt-doped iron oxide nanofluids is investigated in this study. Co-doping in iron oxide nanoparticles changes their magnetic properties, turning them into hard magnets. This, in turn, impacts their interfacial behaviour when exposed to electromagnetic fields. A comprehensive examination of the structural and magnetic properties is conducted on cobalt-doped iron oxide synthesized using the co-precipitation method. Our results indicate a reduction in interfacial tension when electromagnetic fields are applied, using both direct current and alternating current, suggesting potential applications in controlled drug release and enhanced oil recovery processes.

In this paper, Ti isomorphic substituted BiOBr (Ti-BiOBr) is obtained by chemical method. The optimized Ti-BiOBr exhibites superior CO yield of 122.74 μmol·g⁻¹·h⁻¹ which achieves 6.53-fold increasement compared to pristine BiOBr. Due to doping of Ti elements, more oxygen vacancies are formed in BiOBr. The oxygen vacancies and Ti atoms promote the formation of surface frustrated Lewis pairs (FLPs) for BiOBr. The Ti atom is assigned to Lewis acid site, while the neighboring O atom acts as Lewis base site. The substitution of Ti atoms significantly promote the adsorption and activation of CO₂ molecules on surface of BiOBr. This work provides valuable idea for the development of efficient photocatalysts for CO₂ reduction.