Frontiers of Materials Science最新文献

High-performance magnetic materials are critical for the advancements of wireless communication technologies, particularly in the realization of device miniaturization, efficient impedance matching, and low losses performance. Co₂Z ferrite (Ba₃Co₂Fe₂₄O₄₁) is a promising material for radio frequency communication and microwave devices due to its favorable high-frequency magnetic properties and low-loss characteristics. Nevertheless, its performance still requires further optimization to meet the increasing demands of high-frequency applications. Although numerous strategies have been devised to optimize the magnetic and dielectric properties of Co₂Z ferrite, a comprehensive review of these modification strategies remains notably lacking. This review provides a systematic summary of the latest advances in modification strategies, including ion doping, sintering additives, composite fabrication, and texture engineering. It highlights the mechanisms through which each strategy regulates magnetic and dielectric properties. Furthermore, practical guidance is provided for the design and fabrication of high-performance Co₂Z ferrites, so as to promote their application in high-frequency devices.

Nickel–iron layered double hydroxide (NiFe-LDH) demonstrates outstanding catalytic performance for the oxygen evolution reaction (OER) in alkaline media. Herein a general strategy is proposed for fabricating a series of electrodes consisting of NiFe-LDH grown on porous carbon nested in nickel foam (NF) or nickel net (NN). The electrodes exhibit significant OER activity and stability. The porous carbon nested in NF or NN provides a large specific surface area, enabling substantial loading of NiFe-LDH and thereby increasing the number of active sites, which enhances the overall OER catalytic performance. As a result, the NiFe-LDH/C-NF-M-0.1-1200 electrode only requires overpotentials of ∼230 and ∼280 mV to drive a current density of 100 and 800 mA·cm⁻² in 1.0 mol·L⁻¹ KOH, respectively. Moreover, it operates stably at 500 mA·cm⁻² for 14 h. This strategy provides a new approach for the rational design of efficient electrocatalysts for electrochemical applications.

Dye pollutions are persistent organic pollutants that are receiving much attention. Magnetic nanoparticles (NPs) are substantial compounds for the removal of organic dyes from wastewater. In this study, Azadirachta indica (A. indica) extract and polyvinylpyrrolidone (PVP) polymer were used as an encapsulating agent for Ni/Cu-doped α-Fe₂O₃ NPs. Those NPs exhibit rhombohedral crystals with the crystallite size of 14–22 nm in a spherical shape, which have a saturation magnetization value approximately between 30 and 36 emu·g⁻¹ under ambient conditions. Bismarck brown Y (BBY) and Rhodamine B (RhB) dyes were used to test the photocatalytic activity, and results showed that Fe₂O₃ had a removal efficiency up to 96%–98% in 60 min. Fe₂O₃ NPs also demonstrated antioxidant potential against the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, and results suggest that A. indica-encapsulated Fe₂O₃ NPs are potentially fascinating due to greater accessibility of bioactive constituents with antioxidant activities. This research synthesizes biologically generated doped α-Fe₂O₃ NPs with unique structural and morphological features, offering multifunctional applications like antioxidant and photocatalytic capabilities. These novel properties offer potential uses in a diversity of industries, such as environmental cleanup, energy conversion, and biomedical applications.

This review summarizes the past-decade advances in porous materials supported palladium (Pd) nanocatalysts for hydrogenation. Building on the intrinsic 4d¹⁰ character of Pd, we establish a “support-metal-microenvironment” triadic synergy framework that elucidates how oxides, carbons, zeolites, metal–organic frameworks/covalent organic frameworks (MOFs/COFs) and bimetallic modulate activity/selectivity at the atomic scale through electronic engineering, geometric confinement and acid–metal proximity. A three-tier “electronic tuning–interfacial sacrifice–coupled reaction” anti-poisoning strategy is proposed, enabling thermal-atomization regeneration, in-situ water–gas-shift removal of CO, potential-window scavenging of Cl⁻ and micropore anti-sintering. Future perspectives include high-throughput density functional theory (DFT)-plus-machine-learning screening, self-healing intelligent supports and micro-channel continuous-flow processes that will propel green and precise hydrogenation in fine chemicals and hydrogen storage, offering a transferable paradigm for rational catalyst design.

This work reports a ultraviolet (UV)- and temperature-responsive dissolving microneedle matrices based on cinnamoyl-functionalized poly(hydroxyethyl acrylate-co-butyl methacrylate) (Cin-poly(HEA-co-BMA)) for controllable transdermal delivery. The lower critical solution temperature (LCST) of the copolymer decreased with increasing hydrophobic moieties, while UV irradiation increased the LCST via cinnamoyl photoreaction, enabling light-regulated thermal responsiveness. Pyramidal microneedle matrices exhibited an elastic–fracture–elastic deformation behavior under compression, with a Young’s modulus of 0.187–0.221 MPa, and UV treatment further enhanced their mechanical strength. Nearly 100% skin penetration efficiency was achieved, particularly for UV-treated needles. Dye permeation at 37 °C was significantly higher than that at 25 °C, whereas UV irradiation effectively suppressed this thermally promoted permeation by elevating the LCST. This dual-responsive microneedle matrix system provides a programmable strategy for mechanically robust and externally regulated transdermal delivery.

The performance of micro-/nano-electromechanical systems (M/NEMSs) has been significantly improved through the integration of two-dimensional (2D) nanomaterials such as graphene, transition metal chalcogenides and hexagonal boron nitride, mainly due to their excellent mechanical strength, high electrical conductivity and superior thermal and chemical stability. Moreover, the fabrication, integration and functional properties of 2D nanomaterial-based M/NEMSs have been the subject of extensive research, especially regarding device reliability, packaging and pathways to large-scale commercialization. Furthermore, in the fields of biosensing and medical diagnostics, the inherent biocompatibility, photoactivity, and mechanical flexibility of 2D nanomaterials enable rapid response and high-sensitivity detection. Finally, future industrial applications will rely on scalable and cost-effective packaging solutions. The MEMS market is expected to grow at a compound annual growth rate (CAGR) of 7.9%, from $16.5 billion in 2024 to $24.2 billion in 2029.

Knitted flexible sensors, owing to their looped architecture, exhibit excellent stretchability, comfort, and responsiveness, enabling real-time monitoring of biomechanical motion. Here, we systematically investigated the electromechanical performance of conductive fabrics composed of stainless steel, silver-plated, and copper-plated yarns across rib, half-air layer, and air-layer knitting structures. Among them, copper-plated rib fabrics with (35r × 35r)/5 cm density demonstrated superior sensing performance, with stable resistance variation (∼2 to ∼1 kΩ from 0° to 90° wrist bending), high linearity (R²= 0.959), good stability (δ = 0.232 after 100 cycles), and a gauge factor (GF) of ∼2.73. An equivalent resistance model was established to elucidate the impact of loop geometry on sensor performance, confirming that higher coursewise density lowers resistance and enhances sensitivity. A wearable knitted wristband sensor was fabricated that accurately distinguishes wrist postures. These findings highlight the potential of structured conductive knits as customizable, high-performance platforms for next-generation wearable health monitoring and rehabilitation systems.

During secondary recrystallization of oriented electrical steels, the dispersed inhibitors strongly hinder grain boundary migration. The existing secondary recrystallization theories, which mainly focus on the initial migration behavior of grain boundaries, not only fails to clarify the mechanism of secondary recrystallization, but also cannot explain the common phenomenon that smaller Goss grains can eventually engulf all other grains. This study confirms that the significant molar volume effect generated by the precipitation of inhibitors within the ferrite matrix strongly inhibits the coarsening of the central layer inhibitors in steel sheets at high temperatures, but there is still a chance for coarsening of the surface layer inhibitors. Therefore, the surface grains can grow before the growth of grains in the central layer. The highly enhanced elastic anisotropy of ferrite at high temperatures results in slow boundary migration of surface large-sized non-Goss grains towards Goss grains, while surface Goss grain boundaries can quickly migrate towards adjacent small-sized non-Goss grains, allowing Goss grains to gradually accumulate an absolute advantage in larger size, engulf all other grains, and ultimately form a strong Goss texture.

Myocardial infarction (MI) remains a major cause of morbidity and mortality worldwide, stemming from the heart’s limited regenerative capacity and formation of noncontractile fibrotic tissue. Current treatments, including pharmacological and surgical interventions, manage symptoms and restore perfusion but fail to promote regeneration. Hydrogel-based therapies offer a promising approach by mimicking the cardiac extracellular matrix (ECM), delivering bioactive molecules, and providing structural support for repair. This systematic review examines recent advances in hydrogel-based cardiac repair, focusing on classification, therapeutic mechanisms, preclinical/clinical findings, and translational challenges. Hydrogels are classified as natural, synthetic, and hybrid ones, each with unique mechanical and biological properties. Key mechanisms include angiogenesis stimulation, inflammation modulation, ECM remodeling, stem cell encapsulation, and electrical conductivity enhancement. Preclinical studies demonstrate reduced infarct size, improved left ventricular function, and enhanced cardiomyocyte survival. However, clinical translation is limited, with few early-stage human trials to date.

This review article examines the innovative incorporation of microbeads into hydrogels for wound healing applications, addressing challenges such as infection, scarring, and delayed recovery. Hydrogels are highlighted as effective wound dressings for tissue regeneration, while microbeads serve as versatile carriers for controlled drug release and targeted delivery, allowing customization for specific therapeutic needs. This article explores various preparation methods and materials for microbeads, emphasizing their role in enhancing the antibacterial properties and drug delivery functions of hydrogels. Key properties of microbeads-assisted hydrogels, including biodegradability, biocompatibility, and mechanical strength, are discussed as essential for effective wound management. The integration of microbeads improves drug delivery, antibacterial effects, and tissue regeneration capabilities, providing multifunctional solutions for wound healing. Additionally, the mechanisms of antibacterial agent release are described, focusing on controlled and sustained delivery to wound sites. Applications of microbeads-assisted hydrogels cover drug delivery, antibacterial action, tissue regeneration, and sustained release of growth factors, addressing various wound healing challenges. This article concludes by highlighting significant advancements in wound healing strategies facilitated by the integration of microbeads, promising enhanced therapeutic outcomes for patients.