Advanced Composites and Hybrid Materials最新文献

The rapid development of information and communication technology has led to a considerable increase in electromagnetic pollution, prompting the necessity for designing microwave-absorbing materials as an unavoidable trend. The incorporation of magnetic materials can enhance the magnetic loss capacity of microwave-absorbing materials, thereby improving their absorption performance. However, magnetic materials, especially the high-density metals or oxides, are unsuitable for the lightweight design principle of microwave-absorbing materials. In recent years, metal–organic frameworks (MOFs), particularly magnetic metal-based MOFs, are considered advantageous competitors in designing high-performance microwave-absorbing materials because of their high porosity, adjustable structure, and inherent magnetism. This review summarizes the recent progress in studies of microwave-absorbing materials using magnetic metal-based MOFs and their derivatives, including their synthesis process, microwave absorption mechanisms, and comparisons of absorbing performances for MOFs-derived materials with different compositions and microstructures. Finally, potential challenges and future development prospects that MOF-derived composite materials may face in the field of microwave absorption are put forward. We hope to shed light on the mechanism of microwave absorption for magnetic metal-based MOFs, as well as the effect of subsequent processing on the MOF precursor in this regard.

Recent years have seen a rise in the use of carbon fiber (CF) and its composite applications in several high-tech industries, such as the design of biomedical sensor components, 3D virtual process networks in automotive and aerospace parts, and artificial materials or electrodes for energy storage batteries. Since pristine CF have limited properties, their properties are often modified through a range of technologies, such as laser surface treatment, electron-beam irradiation grafting, plasma or chemical treatments, electrophoretic deposition, carbonization, spinning-solution or melt, electrospinning, and sol–gel, to greatly improve their properties and performance. These procedures cause faulty structures to emerge in CF. The characteristics and performances of CF (thermo-electric conductivity, resistivity, stress tolerance, stiffness and elasticity, chemical resistivity, functionality, electrochemical properties, etc.) vary greatly depending on the modification technique used. Thus, the purpose of this review is to demonstrate how the insertion of faults can result in the production of superior CF. The characteristics of CF defects were examined using a variety of analytical techniques, such as defect-forming chemistry, molecular organization, and ground-level chemistries like their crystallinities. Finally, some future work is also included.

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The rapid growth of strain sensors in cutting-edge applications, including wearable human–machine interfaces, electronic skins, soft robotics, and advanced healthcare, has greatly heightened the demand for high-performance hydrogels. In this report, we demonstrate a multifunctional, highly stretchable, and robust conductive hydrogel composed of polyacrylamide (AM), 2-hydroxyethyl acrylate (HEA), and lithium chloride (LiCl) reinforced by zeolite imidazolate frameworks-8 (ZIF-8) through a one-pot free radical polymerization method. The synergy of electrostatic interactions between the AM-HEA polymer chain and nanoporous ZIF-8 enhances the mechanical properties, while the abundant hydrogen bonds originating from the polarized surface of ZIF-8 also introduce multifunctionality to the nanocomposite hydrogel. Tuning the composition of ZIF-8 within the hydrogel matrix results in the attainment of outstanding properties such as excellent stretchability of 808%, high toughness of 453.5 kJm⁻³, and minimal hysteresis as low as 2.6%. Notably, the nanocomposite hydrogel displays strong adhesion, self-healing properties, and resilience in freezing temperatures down to − 20 °C. Furthermore, the as-developed strain sensor exhibits relatively high sensitivity with a gauge factor of 2.98 across a wide dynamic range, along with fast response and recovery times of 280 ms and 330 ms, respectively. The multifunctionality and electromechanical properties of ZIF-8 enhanced high-performance hydrogel hold promise for its application as a wearable, flexible, and stretchable strain sensor for detecting human physiological activities and providing vital biomechanical information for health assessment.

Computer-assisted smart neurotherapy (CASNuT) is an emerging technology used for psychiatric rehabilitation, neurological rehabilitation, and schizophrenia to improve treatment and clinical decision-making. Combined mental practice (cognitive control) and physical practice (bending fingers) were incorporated into the prepared CASNuT. It is constructed using the network of multifunctional piezo-tribo hybrid (PDMS/BCST) composite film-based intrinsic hybrid nanogenerators (which acts as a mechano-electric sensor for the smart gloves) and computation with the interfacing circuit/display devices. Successful integration of piezoelectric and triboelectric charges enhanced the intrinsic hybrid nanogenerator output (426 V, 1.72 mA/m², and 368.66 µW/m² at 100 MΩ) and sensing properties. Next, it demonstrated rehabilitation treatment (via CASNuT) and smart medical assistance using a mechano-electric smart medical glove. Computer-aided or assisted therapy computes for better assistance and treatment.

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Flexible magnetic materials have great potential for biomedical and soft robotics applications, but they need to be mechanically robust. An extraordinary material from a mechanical point of view is spider silk. Recently, methods for producing artificial spider silk fibers in a scalable and all-aqueous-based process have been developed. If endowed with magnetic properties, such biomimetic artificial spider silk fibers would be excellent candidates for making magnetic actuators. In this study, we introduce magnetic artificial spider silk fibers, comprising magnetite nanoparticles coated with meso-2,3-dimercaptosuccinic acid. The composite fibers can be produced in large quantities, employing an environmentally friendly wet-spinning process. The nanoparticles were found to be uniformly dispersed in the protein matrix even at high concentrations (up to 20% w/w magnetite), and the fibers were superparamagnetic at room temperature. This enabled external magnetic field control of fiber movement, rendering the material suitable for actuation applications. Notably, the fibers exhibited superior mechanical properties and actuation stresses compared to conventional fiber-based magnetic actuators. Moreover, the fibers developed herein could be used to create macroscopic systems with self-recovery shapes, underscoring their potential in soft robotics applications.

Design and development of environmentally friendly composite materials is underway in response to escalating environmental concerns and the looming scarcity of petroleum-based resources. A key strategy in this endeavor is the application of biologically derived polymers, reinforced with organic fibers. This approach has appeared to be a potent substitute for synthetic fiber-reinforced polymers in the development of composite materials. Among the organic fibers, bamboo has seen a surge in popularity due to its wide availability, cost-effectiveness, biodegradability, and superior mechanical properties. However, bamboo fiber is combined with other natural fibers in order to maximize the performance, address limitations, and broaden the scope of application of bamboo fiber-reinforced hybrid polymer composites. This review covers topics including the anatomy of bamboo and the chemical composition of bamboo fiber. Later on, different aspects of hybrid composites such as configurations of fibers and polymers, orientation of fibers, mechanical properties, thermal properties, biodegradability and applications in aerospace, ballistic protection, automotive, structural, filtration, electrode, electromagnetic wave absorption, sensor technologies, and infrared shielding are discussed. This review also highlights several problems and solutions in the development of bamboo hybrid composites. This article offers valuable perspectives and recommendations for those engaged in the field of green composites, paving the way for the creation of sustainable materials suitable for diverse applications.

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Recently, aptamers have been widely used in the detection and measurement of cancer biomarkers. This issue has had a significant impact on the process of diagnosing all types of cancers. This research work explores the development and application of layer-by-layer modified electrochemical apta-sensor for the precise monitoring of HER2, a crucial biomarker associated with breast cancer. The surface of the screen-printed carbon electrode was modified with gold nanoparticle (Au-NP) and TiVC MXene catalyst plus Pb²⁺ loaded aptamer (SPCE/TiVC-MXene/Au NPs/Pb²⁺-aptamer), which showed a high selectivity and affinity towards HER2 and offered a sensitive detection platform. The MXene nano-layer was synthesized and characterized by XPS, MAP, EDS, AFM, BET, and TEM methods and used as a substrate to improve electrochemical conductivity and loading of biological recognition element. The square-wave anodic stripping voltammetry (SWASV) method was used as a highly sensitive platform in HER2 detection. The difference of stripping signals of the Pb²⁺ from the SPCE/TiVC-MXene/Au NPs/Pb²⁺-aptamer before and after incubation in HER2 solution was selected as analytical response to achieve a reliable and quantitative analysis for HER2 concentrations. The effective factors in monitoring of HER2 such as concentration of Pb²⁺, incubation time, and buffer type were optimized and results showed that 5 mM of Pb²⁺ and 90-min incubation time in Tris–HCl created best condition in fabrication of biosensor. The results demonstrate a linear dynamic range of 1.0–1200 pg/mL for monitoring of HER2 with limit of detection of 50 fg/mL. A good affinity of fabricated apta-sensor to HER2 in the presence some other biomarkers such as PR, ER, and CEA confirmed the selectivity of the fabricated biosensor towards HER2 detection.

Hematite (α-Fe₂O₃) can be a promising photoelectrode to promote the development of photoelectrochemical water splitting (PEC-WS), but the low photogenerated carrier separation efficiency limits the further application. In this work, a nano-heterojunction is constructed by a metal–organic framework (MOF-5) and α-Fe₂O₃ films to regulate photogenerated carrier transport. The electronic structure regulation (element doping and electron-donor functional groups) is introduced to solve the problems of poor electrical conductivity of MOF-5 and interface defects and band mismatch caused by contacting with α-Fe₂O₃ film. The α-Fe₂O₃/NH₂:MOF-5(Ni)@Ru photoanode exhibits the optimal photocurrent density of 2.6 mA/cm² at 1.23 V_RHE, which is 2.68 times of the pure α-Fe₂O₃ photoanode. This can be attributed to that the introduction of MOF catalyst can provide more abundant active sites for PEC water oxidation. The element codoping and synergistic effect of Ni and Ru improve the conductivity and inhibit the recombination rate of photogenerated electron–hole pairs of α-Fe₂O₃ photoanode. The electron-donor functional group of –NH₂ can regulate the electron distribution to prolong the lifetime of photogenerated holes, which further enhances the photogenerated carrier separation and transfer efficiency.

The harmony between glass-forming ability (GFA) and soft magnetic properties (SMPs) of Fe-based amorphous/nanocrystalline alloys has garnered considerable attention. Herein, a prototypical FeSiBCu amorphous alloy system by microalloying P was investigated regarding the GFA, thermal stability, SMPs, and microstructure. It was found that including P not only raised the degree of amorphous disorder but also facilitated the precipitation of α-Fe(Si) grains and widened the annealing window. Furthermore, adding P changed the optimal crystallographic orientation of the α-Fe(Si) phase and enhanced the growth competition of grains with different orientations, which promoted grain refinement (The average grain size was decreased from 61.36 to 21.24 nm). After optimal annealing processing, the ribbons with 8 at.% P addition displayed a lower coercivity (H_c) of 4.61 A/m. While the 4 at.% P-added ribbons exhibited a higher saturation magnetic flux density (B_s) of 1.75 T. The distinctive mechanism of grain preferential growth in FeSiBPCu alloys provides relevant guidance on the correlation between nanocrystalline structure evolution and the modulation of SMPs.

Polymer-based self-adaptive dielectrics are considered promising materials to meet the growing insulation needs of flexible electronic devices and high-voltage DC cables. However, the temperature-sensitive electrical performance and poor thermal management ability of polymer dielectrics are bottlenecks that limit their further development. Here, we report a novel three-dimensional microstructure, i.e., nonlinear silicon carbide (SiC) micromaterials loaded on sodium alginate (SA) aerogel, exhibiting satisfactory non-linear electric conductivity with ultra-high thermal conductivity (3.86 W m⁻¹ K⁻¹, compared to 0.21 W m⁻¹ K⁻¹ of the pure epoxy resin). The SA aerogel, rich in high-density pores, is conductive to SiC forming a highly interconnected network structure under low loading, which endows polymer composites with the ability to quickly disperse charges under high electric field. In addition, the three-dimensional interconnected SiC network can disperse the Joule heat from local currents generated by nonlinear behavior, preventing thermal breakdown caused by the adverse effect of heat accumulation on the electrical properties of the material. In combining the advantages of nonlinear electrical conductivity characteristics, high thermal management ability, and low load capacity, this strategy expands the application scenarios of electric field self-adaptive polymer materials under high-temperature conditions.

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We report a novel three-dimensional microstructure dielectric composite with self-assembly SiC on sodium alginate aerogel. Due to the high interconnectivity and porous structure of SA aerogel, efficient construction of conducting paths is achieved at a low filler content (1 vol%), which endows the composite with satisfying nonlinear conductivity and thermal management capacity.