Advanced Composites and Hybrid Materials最新文献

With the trend toward miniaturization of functional devices, material preparation and thermal management processes are also limited to small spaces. Microchannels have emerged as an optimal solution for these challenges. Microchannel-based reactors can generate hybrid materials, and the integration of microchannel heat sinks and substrates can control the temperature of high-power devices. The microstructure within microchannels significantly influences fluid flow and heat transfer, impacting the efficiency of both reaction and heat dissipation processes. Pin-fins are widely used microstructures due to their ability to increase heat transfer area and enhance fluid mixing. In order to find the optimal structure of the fins, it is essential to explore a vast parameter space. In this paper, artificial neural network and genetic algorithm are combined to optimize the copper irregular pin–fin microchannels. Initially, a large number of numerical simulations are performed, focusing on adjustable parameters such as fin radii in various directions, while monitoring the heating surface temperature and the pressure drop of the fin section. Then, nearly 2000 sets of accumulated data are used to train the neural network, establishing the relationship between structural and performance parameters. Finally, a genetic algorithm is employed for multi-objective optimization, yielding a Pareto front. The findings reveal that the newly obtained optimized microchannels exhibit superior thermal–hydraulic performance compared to traditional microchannels. The mechanism of heat transfer enhancement in the optimized microchannel has been revealed: the arrangement of asymmetric fins allows for more thorough contact between the fluid and the fins. Based on this rule, the newly designed multi-fin microchannels exhibit better performance under both fixed heat flux and fixed temperature conditions. In addition, doping high thermal conductivity materials into the substrate to form composite materials can significantly improve the heat transfer performance of microchannels, and using materials with different doping ratios in different parts of the microchannel can effectively improve the temperature uniformity of the heating surface. Thus, uniform-temperature microchannels are designed by combining metal materials (such as copper and aluminum) with non-metal materials (like diamond and graphite).

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The paper comprehensively reviews the upcycling and utilization of agri-food loss and wastes (FLWs) in poly(lactic acid) (PLA)-based biocomposites from the perspective of material circularity. The massive volume of unwanted and unvalued FLWs contributed from fruit producers (durian husk, pineapple leaf, orange peel, and apple), post-consumer products (spent coffee ground, sugarcane bagasse, coconut husk, crustacean shells), and agricultural sectors (rick husk, rice straw, wheat straw, and corn stover) is generally discarded and incinerated. Notably, these FLWs can be collected and upcycled into valuable products depending on the final application, endowing them with a meaningful second life. This upcycling approach promotes environment-friendliness and reduces the product’s carbon footprint. However, gaps and challenges in creating high-performance biocomposites remain critical to a translatable product. To address that, this review comprehensively discussed the recent progress and strategies to enhance the compatibility of PLA and the various FLW biocomposites, such as improved processability, well-balanced properties, heat resistance, and increased interfacial adhesion. The overall mechanical, thermal, processability, and biodegradability performances are further examined and elaborated. Furthermore, the current and prospective applications, such as packaging, automotive, construction, and 3D printing of FLWs/PLA products, are discussed. Finally, the prospects and opportunities of these FLWs/PLA biocomposites are shared to give a view into the future.

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Reducing the weight and profile of machinery and robotics is currently a prime challenge for materials scientists and engineers alike. Solving this challenge could lead to an improvement in space travel feasibility, manufacturing capability, and the birth of new medical interventions and technologies altogether. LCEs are currently considered to hold good potential as artificial muscles due to their unique molecular structure. With the recent boom in materials science and the emergence of advanced fabrication techniques, LCE-based artificial muscles/flexible actuators are at the cusp of commercialization. LCEs can now be fabricated into several different forms (films, fibers, and 3D printed arbitrary shapes). Furthermore, LCE artificial muscles fabricated using these advanced techniques can also be functionalized so that they can controllably be triggered into actuating via stimuli such as light or electrical currents. This has led to reports of several LCE-based artificial muscles which boast impressive performance as artificial muscles. For example, recently certain Joule heating LCE fibers can directly be stimulated into actuation via the application of electrical currents and can actuate on sub-second time frames and outperform human skeletal muscles in terms of actuation stress. Given this, whilst currently there are no commercial applications of LCEs as artificial muscles in robotics, we believe that LCEs are poised to soon be directly applicable as artificial muscles in the broader field of robotics, which inspired us to author this review. This review presents an overview of the mechanisms, synthetic methods, and alignment methods for LCEs. In addition, we provide the latest achievements in fabrication techniques and means of inducing/controlling the actuation of LCEs. We do so in the aspiration that this review can bridge the gap that exists between academia and industry on the topic of LCEs.

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Illustration of LCEs acting as artificial muscles in robotics.

The rapid development of information technology and the continuous advancement of industrialization have made the problems of electromagnetic (EM) pollution and energy shortage more and more prominent, which have become major challenges that need to be solved worldwide. Developing multifunctional EM materials has become a key solution for addressing these issues, advancing sustainable development, and establishing effective environmental protection systems. Herein, we prepare CuS/GO heterodimensional structures with both EM protection and electrochemical energy storage functions. Benefiting from the synergistic effects of the components and structure, the CuS/GO heterodimensional structure exhibits outstanding performance in microwave attenuation and sodium storage applications. The CuS/GO composite with a loading concentration of 55 wt.% achieves highly efficient EM wave absorption of − 62.56 dB, while the 75 wt.% composite demonstrates electromagnetic interference (EMI) shielding performance of more than 50 dB. In addition, in sodium-ion battery applications, the CuS/GO heterodimensional structure maintains a high reversible capacity of 377 mAh·g⁻¹ after 700 cycles. Importantly, based on this, an integrated multifunctional EM wave recovery device has been developed that can effectively convert harmful EM energy into electrical energy and store it. This provides a groundbreaking innovative strategy for the design of multifunctional devices in the fields of EM pollution control and energy applications.

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Supercapacitors are a fundamental technology in electrical energy storage because of their high performance and cycling. In this study, using a conductive type of nanocomposites, we tested electrode designs in the application of supercapacitors, obtaining valuable results in energy capacity and power density. MnO₂-Fe₂O₃/N-doped graphene nanoribbons (MFNGN) were prepared by an efficient multistep approach. The synthesized result demonstrated that the large surface area of the nanocomposite causes faster transfer of ions and electrons and increases the internal electronic fields with interconnecting nanoscale pore channels for ion transport to adjust the electronic structures. High surface area-to-volume ratio also provides numerous active sites for electrochemical reactions. Consequently, surface area makes available active sites for electron transfer process and also improved the electrochemical performance of the electrodes by improving the electron transfer rate charge transfer capacity. The results demonstrated good cycling stability, with 87.56% of the initial capacity retained after 10,000 cycles at 5.0 A·g⁻¹. Furthermore, a hybrid supercapacitor that uses the MFNGN as a positive electrode and active carbon (AC) as a negative electrode was created. This combination resulted in an asymmetric supercapacitor (ASC) that exhibited exceptional performance. Specifically, it achieved a remarkable specific capacitance of 770.0 F·g⁻¹ when subjected to a current density of 1.0.

Information leakage and counterfeiting are critical global issues threatening human security and social stability. Advanced flexible anti-counterfeiting technologies are urgently needed, as flexible wearables are becoming more and more significant. In this study, we report a straightforward and efficient wet spinning technique to prepare lanthanide-alginate hybrid fibers with multicolor-emitting capabilities for flexible anti-counterfeiting. Lanthanide ions are able to coordinate with sodium alginate to endow the hybrid fibers with good molding properties, thermal stability, and homogenicity. These hybrid fibers can emit red, orange, and green fluorescence depending on the ratios of doped lanthanide elements under 254 nm UV light. The fluorescence lifetime of these hybrid fibers is longer than that of commonly used organic dyes. Notably, their fluorescence can be quenched in acidic environments or by Fe³⁺ ions, which is ascribed to the weakened coordination strength between 2,2′-bipyridine with the lanthanide elements. More importantly, the hybrid fibers can be woven into various flexible anti-counterfeiting patterns. Our study demonstrates the significant flexible anti-counterfeiting potential of lanthanide-doped fibers due to their low cost, ease of fabrication, and flexibility.

Graphical Abstract

The multicolor-emitting lanthanide-alginate hybrid fibers with multi-stimuli responsiveness are produced through a simple wet spinning process and can be woven into various patterns for flexible anti-counterfeiting.

Neurodegenerative diseases pose significant challenges to global healthcare, exacerbated by complexities of the central nervous system and blood–brain barrier. While FDA-approved magnetic nanocarriers offer promising solutions for targeted drug delivery, inherent challenges in predicting delivery performance still hinder clinical practice. Existing brain vasculature transport models often lack accuracy in the 3D construction of the brain vasculature network and physiology of blood circulation, limiting progress in targeted drug delivery. This paper introduced the Circle of Willis’s novel computational fluid dynamics framework to address these challenges. Utilizing patient-specific vascular geometries and incorporating complexities of blood circulation, hemodynamics, and the rheology for non-Newtonian fluid effect, our approach provides unprecedented insights into drug carrier dynamics in the mouse brain vasculature. Furthermore, we performed a comparative study simulating the dynamic transport using three types of magnetic nanocarriers—gold-coated superparamagnetic iron oxide (Au-SPIO), hollow-gold nano-shell enclosed superparamagnetic iron oxide (HGNS-SPIO), and metal–organic frameworks loaded with iron oxide (MOF-Fe₃O₄)—to predict their transport in adult mice’s brain under magnetic targeting. The simulation was validated by in vivo results by comparing the bioavailability of nanoparticles in different brain regions. Under a non-magnetic field, simulations revealed a capture efficiency of around 10.5% for all three types of nanoparticles, with size-dependent patterns favoring smaller sizes. With the presence of a magnetic field, MOF-Fe3O4 demonstrated the highest capture efficiency with “single magnet” at 11.19%, while Au-SPIO in “linear Halbach array” and MOF-Fe₃O₄ in “circular Halbach array” layouts reached 10.9%. Finally, we demonstrated high biocompatibility for all three nanocarriers, with no toxicity for Au-SPIO and MOF-Fe₃O₄ at 40 µg/mL and for HGNS-SPIO at 20 µg/mL. Effective cell uptake was also observed for all three nanocarriers. This comprehensive study addresses critical knowledge gaps, providing insights into the dynamics of magnetic nanocarrier transport within the brain and paving the way for highly effective, personalized therapies for neurological disorders.

Recent considerable research efforts have been directed toward optimizing ceramic/polymer composite materials at the design stage, with a focus on enhancing thermal conduction pathways through distinct structures. This study introduces a simple process of adopting the template method followed by sintering to create a lightweight, self-supporting MgO framework with smooth-surfaced, highly thermally conductive MgO spheres. The segregated structure of inorganic ceramic particles significantly reduces thermal resistance and increases the thermal conduction path. Consequently, these composites exhibit notably higher thermal conductivity (6.61 W/mK) at a filler loading of 51.94 vol% compared to those with randomly dispersed particles. Additionally, 20.27 vol% 3D-MgO/epoxy composites with a thermal conductivity of 2.71 W/mK display a relatively low dielectric constant (3.78 at 1 kHz), only slightly higher than pure epoxy (3.39 at 1 kHz) with a thermal conductivity of 0.19 W/mK. This low dielectric constant is advantageous for electronic and electrical engineering applications. The study proposes an effective strategy for using MgO as an alternative to Al₂O₃ fillers in high-power-density electronic devices, making 3D-MgO/epoxy composites a promising next-generation thermally dissipating material for electronic devices.

The investigation and understanding of heterointerfaces formation and charge transfer dynamics in two or more semiconductor heterojunctions increased ensuing establishment of S-scheme and dual S-scheme heterojunctions. However, investigations of possible charge transfer at interfaces and their type in four component systems are limited. Herein, a four-component heterojunction was investigated to postulate and demonstrate deviation between quadruple and triple S-scheme heterojunctions possibilities using LaNiO₃, BiOBr, CuBi₂O₄, and Bi₂WO₆. DFT and XPS were used to construct the band structure and support the charge transfer at the interfaces to follow S-S strategy during OTC and SMX degradation under visible light. IEF, bend bending systematically modulated charge transfer, and the core-shell strategy restricted possible junctions’ formation to three to accord triple S-scheme heterojunction. This work demonstrated the construction of Triple S-scheme heterostructures as a promising strategy for efficient charge separation making it a suitable candidate for elimination of pollutants.