Advanced Composites and Hybrid Materials最新文献

Flexible wearable heater plays a critical role in maintaining a consistent human body temperature, particularly during outdoor activities in cold environments, where garment elasticity, stretchability, and mechanical strength are paramount. Thus, there is an urgent demand for the development of flexible wearable heaters. In this study, we have successfully engineered a photo-thermochromic elastic fiber with control over its color properties via a continuous wet-spinning process. Through the incorporation of a modest amount (as little as 0.5%) of photothermally active polyaniline (PANI) and polydopamine (PDA) nanoparticles, this fiber exhibits exceptional photothermal conversion performance compared to pure thermoplastic polyurethane (TPU) fiber. Notably, when exposed to 600 W m⁻² irradiation for 600 s, the equilibrium temperature of the photo-thermochromic elastic fiber rises impressively from the ambient 20.0 °C to 53.5 °C. A significant feature of this fiber is its reversible color-changing capability, which can be conveniently controlled by manipulating the light source. This innovative characteristic empowers the user to monitor the fiber’s temperature by observing its color shifts. Furthermore, the fiber boasts exceptional stretchability, with an impressive elongation capacity of up to 500%, and remarkable resistance to washing, enduring up to 25 cycles. Taking this innovation further, we integrate the fiber into a fabric that maintains its superior photothermal conversion performance, mechanical resilience, and the ability to undergo reversible color changes when exposed to sunlight. This stretchable and vibrant photo-thermochromic elastic fiber holds significant promise as an energy-efficient alternative and is poised to find exciting applications in the realm of smart textiles.

In this paper, the recrystallization behavior of 4043 aluminum alloy under the deformation conditions of dwell times of 1 s, 10 s, 30 s, and 90 s between passes was studied. The results show that when the inter-pass dwell time is increased to 10 s, the instability region in the material hot processing map disappears. Additionally, particle-stimulated nucleation (PSN) predominantly occurs at low deformation temperatures and in specimens with short inter-pass dwell times under high deformation temperatures. Importantly, at a deformation condition of 450 °C and a strain rate of 0.01 s⁻¹, when the inter-pass dwell time is increased to 90 s, the alloy texture type changes from a strong Goss texture to a strong rotated cube texture, with the primary recrystallization mechanism shifting from PSN to continuous dynamic recrystallization (CDRX). A longer dwell time of 90 s tends to achieve the maximum static softening rate and a higher recrystallization fraction (8.54%). These findings reveal the impact of inter-pass dwell time on the hot deformation behavior of 4043 aluminum alloy, providing theoretical guidance for industrial production.

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The effect of dwell time on recrystallization behavior and the recrystallization mechanism of PSN were studied.

Here, we report a general strategy for designing a metal/carbon system, via a facile and environmentally friendly one-step approach, from metal acetate as an active electrocatalyst in oxygen evolution reaction (OER) during water decomposition. As a demonstration, a nanostructured Ni/C composite induced from nickel acetate is revealed in great detail. The resulting material is composed of: metallic nickel (Ni), nickel(II) oxide (NiO), and nickel carbide (Ni₃C) coated with a graphitic shell and deposited on a carbon platform. Our findings underscore the prominent role of nickel species, including Ni⁰, Ni²⁺, and Ni³⁺, in driving the catalytic activity. Notably, the catalyst exhibits an overpotential of 170 mV, a Tafel slope of 49 mV·dec⁻¹, an electrocatalytic surface area (ECSA) of 964.7 cm², and a turnover frequency (TOF) value of 52.8 s⁻¹, surpassing RuO₂. The Raman spectra also suggest a graphitic "self-healing" phenomenon post-OER, attributed to the reduction of oxygen-containing groups. Carbon in the system (i) facilitates electron transfer, (ii) allows homogeneous distribution of Ni nanoparticles avoiding their agglomeration, and (iii) promotes durability of the electrocatalyst by serving as a protective barrier, shielding the core metal compounds. What is more, density functional theory (DFT) calculations allowed to optimized geometry of the model cluster Ni₈O₈(OH)₈ describing two different sites on the β-NiOOH surface (001) and two different intermediates, (i)L-OOH and (ii)L-OOH. This facilitated to propose the reaction mechanisms involving both hydroxide ions and water molecules as reducers. Therefore, the chemisorption of OH⁻ and H₂O molecules at the NiOOH active center accompanied by bond breakage and the formation of a lattice hydroperoxide as an important intermediate is presumed. What is more, the proposed fabrication method for electroactive metal/carbon composites was validated with an iron and iron/nickel mixture.

A sustainable polymerized base-activated biochar (PBC-B) derived from Punica granatum peel and surface activation and polymerization with branched poly(ethylenimine) were prepared and demonstrated efficient tetracycline (TC) remediation from wastewater. Polymerized acid-activated biochar (PBC-A) and pristine biochar were also evaluated for comparison. The PBC-B exhibited enhanced porous morphology and surface functional groups, effectively improving TC adsorption. Results indicated that PBC-B has a Langmuir adsorption capacity of 295.9 mg g⁻¹ and a partition coefficient of 18.67 mg g⁻¹ µM⁻¹, manifesting that surface activation and polymerization lead to well-developed pore structures. The PBC-B showed a 19.59 and 75.39% improvement in TC adsorption compared to PBC-A and BC, respectively. Adsorption isotherm studies revealed that the Langmuir model described the strong adsorption behavior with a high adsorption capacity (Q_L = 295.9 mg g⁻¹) and R² (0.98) for PBC-B. Kinetic studies indicated that the pseudo-second-order model fits well, with a low sum of squared error values (< 4.4 × 10⁻³) and high R² values (0.99). This study pioneers the use of PBC as an adsorbent with reduced organic compound content while elucidating the TC adsorption mechanism in aqueous phases, marking a significant advancement in the field. Density functional theory evidenced that chemisorption mechanism predominates in the interaction between TC and PBC.

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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