Advanced Composites and Hybrid Materials最新文献

Rapid wound closure is crucial to prevent microbial invasion during skin trauma. Delayed diagnosis and treatment of wound infection may lead to complications such as impaired healing and sepsis. Conventional clinical dressings (e.g., cotton and gauze) mainly provide physical isolation but fail to establish an antibacterial microenvironment. These dressings often adhere to wound tissues, resulting in secondary injury during removal, and lack the capability for real-time monitoring of wound conditions. This study innovatively integrates multimodal pressure sensing with wound repair functions, enabling the synergistic development of smart sensing wound dressings (SSWD) that offer real-time visual monitoring. The dressing employs gradient cross-linking to fabricate a dynamic self-adaptive Janus-structured organic hydrogel. The upper non-adhesive ion-sensing layer incorporates micro-nano surface structures, enabling high-resolution real-time responses to mechanical signals from wound swelling and tissue regeneration. This capability, when coupled with an image acquisition system, enables visual monitoring of the healing process. The lower adhesive layer ensures robust interfacial integration with the wounds’ bed via hydrogen bonding while allowing controlled sustained release of drugs that promote healing. This system propels the development of intelligent dressings towards diagnosis-treatment integration and offers an innovative solution for precision wound management.

Overcoming the strength-ductility trade-off remains a daunting challenge for titanium (Ti) industry. Duplex (α + β) Ti alloys, represented by Ti-6Al-4 V, are the mainstay of Ti industry. However, the poor deformability of hexagonal close-packed (HCP) α phase, combined with semi-coherent α/β boundaries for strain incompatibility often cause limited elongation. Here, we propose an innovative strategy that harnesses O atoms with strong hardening ability in Ti alloys, as well as the rapid cooling and highly thermal gradients of laser powder bed fusion to construct a duplex Ti alloy, involving HCP Ti matrix embedded with O-rich nano-coherent face-centered cubic (NC-FCC) Ti. The duplex Ti-0.615 wt% O alloy achieves a high ultimate tensile strength of 1020 ± 4 MPa and an exceptional elongation of 21.8 ± 0.5%, together with a superior specific strength-ductility product of 4.93 GPa·%·cm³·g^− 1. This unprecedented combination of mechanical properties originates from the O-rich NC-FCC, which promote dislocation slip transfer across the coherent phase boundaries (CPBs) and formation of extensive stacking faults near CPBs for enhanced strain compatibility. Additionally, the O-rich NC-FCCs strengthen the alloy via solid solution strengthening from O atoms. This work opens a promising avenue towards a new generation of lightweight high-performance metallic materials through customized phase engineering induced by interstitial atoms.

Previous studies mainly focus on secondary and tertiary treatment to enhance the microwave absorption performance (MAP) and corrosion resistance of dielectric-magnetic multi-component materials, which increases the production cost and difficulty, and leads to the loss of original properties of some components. In this study, a series of core@shell CoFe@Void@N-doped carbon (NC)@carbon nanofibers (CNFs) pod-like nanocomposites (PLNCs) were prepared to elaborately construct via simple electrospinning and MOF-derived strategy. The acquired outcomes demonstrated that the material composition (CoFe@Void@NC regulation) and stratification structure can be reasonably optimized, the designed CoFe@Void@NC@CNFs PLNCs exhibited an effective absorption bandwidth of 8.00 GHz and minimum reflection loss of -55.77 dB, radar cross section value of -64.94 dB·m², and ultra-wideband of 32.76 GHz in metastructures. Furthermore, the hierarchical pod-like architecture enabled synergistic integration of magnetic-dielectric components and physical barriers across multiple length scales, endowing the CoFe@Void@NC@CNFs with photo-thermal-electric energy recycle and multi-level defense (eg. corrosion resistance and bacteriostatic properties). Especially after 30 days of co-cultivation with bacteria and 7 days of immersion in the simulated marine environment solution, CoFe@Void@NC@CNFs PLNCs still showed excellent comprehensive MAP. Therefore, with the support of multi-level defense functions, core@shell CoFe@Void@NC@CNFs PLNCs with performance-durability is expected to be used in complex and variable marine environments.

Tissue engineering (TE) represents an interdisciplinary field introduced for the recovery, preservation, and improvement of tissue function. Piezopolymers make it possible to generate exogenous potentials close to endogenous ones to promote tissue regeneration. Biodegradable poly(3-hydroxybutyrate) (PHB) has gained particular attention; however, the piezoelectric (PE) response of PHB is poor, and there is a need to improve it without compromising the biocompatibility of the scaffold. Herein, a drastic increase in the PE response of electrospun PHB scaffolds was achieved by incorporation of homogeneously distributed crystals of piezoactive β-glycine (Gly). We successfully optimized the electrospinning parameters to prepare composite PHB fibers with Gly content (5, 15, 20, and 30 wt%) and tailored topography, crystalline structure, and PE response. Gly incorporation creates a nanoporous textured surface of polymer fibers, which improves surface area, surface wettability, and the free surface energy of intrinsically hydrophobic scaffolds. In addition, Gly crystals act as nucleators for PHB crystallization, diminishing the polymer crystallite size and increasing its crystallinity degree from (39.9 ± 0.8) % for pure PHB to (45.8 ± 1.6) % for PHB-Gly-30. Using piezoelectric force microscopy, we obtained distributions of PE response along the fibers, uncovering a considerable increase in the lateral PE response for PHB scaffolds with 30 wt% Gly (from 0.28 ± 0.13 to 3.9 ± 1.0 pm/V) due to (i) the presence of PE β-Gly phase and (ii) higher PHB crystallinity. First-principles calculations revealed that the interaction of the Gly molecule with PHB surfaces occurred predominantly through hydrogen bonding and demonstrated a mechanism ranging from strong physisorption to weak chemisorption. This study opens new fundamental insights into straightforward one-stage engineering of biodegradable piezopolymer properties and offers a prospective scaffold for a wide range of TE applications.

An Al-based functionally graded structure is fabricated, featuring a discrete compositional gradient of 48.1Al47.9Ti4.0V/73.7Al24.2Ti2.1V/89.5Al10.0Ti0.5V in atomic percentage. This structure is produced via dual-hybrid laser powder bed fusion and directed energy deposition combined with computer numerical control milling. Particularly remarkable is the high tensile strength, ranging from 0.5 to 1.7 GPa. This strength is attributable to three key factors: (1) rapid solidification during inert gas flow following high-energy laser irradiation, (2) the formation of γ-like intermetallic matrix phases along with γ′-like (α₂-based in the composition of 48.1Al47.9Ti4.0V) intermetallic precipitate phases, and (3) the presence of segregates and precipitates with more V-based compounds at the grain boundaries, distinguishable by their sizes, shapes, and distributions across the microstructures. In addition, (4) large anisotropically lamellar precipitate phases, several hundreds of nanometers in diameter, are predominantly observed in the dendritic regions. Owing to these Al-based intermetallic compounds, each exhibiting low densities (2.9−3.7 g cm⁻³) and high thermal resistances (450−900 °C), the functionally graded structure is then employed in the topological optimization of a turbine blade system for a high-performance jet engine. This process involves identifying the stress-bearing regions, removing any stress-free areas, and applying a structural-stiffness-increasing mechanism through shape and geometric transformation.

Current research on supercapacitors focuses on achieving high specific energy by expanding the voltage window and improving specific capacitance through advanced electrode design. This study presents a new type of pseudocapacitive integrated electrode developed by decorating α-Fe₂O₃ nanoparticles onto NH₄V₃O₈ multiwalled nanotubes using a simple and efficient method. α-Fe₂O₃ stores energy through conversion reactions, while NH₄V₃O₈ facilitates intercalation-based storage. The difference in work function between α-Fe₂O₃ nanoparticles and NH₄V₃O₈ multiwalled nanotubes generates a built-in electric field at the heterointerface, as confirmed by density functional theory calculations. This built-in electric field enables simultaneous operation at both positive and negative potentials, thereby supporting sulfate ion conversion and sodium ion intercalation. These mechanisms are validated by in situ Raman and ex situ X-ray photoelectron spectroscopy analyses. Owing to the coexistence of multiple energy storage mechanisms and the presence of a built-in electric field, the assembled full cell delivers a high specific energy (79 Wh/kg), specific power (5996 W/kg), and a broad voltage window of 2.2 V. These findings emphasize the effectiveness of the integrated electrode design and represent a significant advancement toward realizing next-generation energy storage technologies for a wide array of applications, ranging from portable electronics to expansive renewable power infrastructures.

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Developing a textile capable of achieving infrared stealth under Joule heating conditions is critical for enhancing the operational effectiveness and survivability of combat troops in challenging climates. Here, a novel type of silver nanowires/bacterial cellulose/carbon fibers composite fabric (ABCF) inspired by the multi-layered structure of beetle elytra and the dual-mode thermal management system was designed for infrared stealth at Joule heating via a facile sewing method. The introduction of an inner layer consisting of carbon fibers serves as an effective heater producer, demonstrating excellent Joule heating performance (~ 210 °C at 3 V). The interlayer made from bacterial cellulose aerogel exhibits thermal insulation properties (0.028 W/m·K) and flexibility, functioning as a barrier that mitigates heat transfer through its layer-stacking structure under directional thermal conduction. Meanwhile, the upper layer comprised of silver nanowires provides low emissivity (~ 0.15) and cooperates with the aerogel to achieve infrared stealth. As a result, ABCF achieves both a significant reduction in thermal radiation temperature for targets and long-term infrared stealth stability (~ 55 °C maintained for 8400 s), with experimental feasibility validated through COMSOL simulations. Impressively, ABCF has been effectively utilized in the construction of tents, further highlighting its potential for multifunctional applications in the field of thermal management.

Control of intermolecular interactions is crucial for regulating self-assembly processes in nature. Herein, using hydrogen bonds as stabilizers, we demonstrate an innovative approach for assembling highly reactive 2D Ta₃N₅ nanomeshes embedded with nitrogen self-doped carbon quantum dots (NCQDs). These Schiff base-derived NCQDs exhibit good hydrophilicity and act as both photosensitizers and electron reservoirs in the hybrid system.​ Strong bonding interactions exist between the H atoms of -OH/-NH groups on the NCQD surface and the N atoms of 2D Ta₃N₅ nanomeshes (i.e., O–H···N and N–H···N hydrogen bonds). These interactions direct the formation of an extended 3D hydrogen-bonded coupling framework. Within the NCQDs/Ta₃N₅ nanomeshes, the internal electric field and interfacial hydrogen bonds provide directional charge-transfer channels, which facilitate the separation and directional migration of photocarriers. Further density functional theory (DFT) calculations reveal that the formed O–H···N and N–H···N bonds significantly reduce the Gibbs free energy barrier of the rate-limiting reaction and the reaction barrier for H₂O dissociation, thereby enhancing the material’s photooxidation and photoreduction activities. Our results establish a close relationship between intermolecular hyperconjugation theory and the photocatalytic mechanism.

Modulating the phase composition and microstructural geometry in polymetallic metal-organic framework (MOF) derivatives represents a promising approach for achieving tunable electromagnetic response. However, deciphering the intrinsic phase-structure-property correlations in complex systems remains challenging. Herein, a competitive coordination and directed reduction strategy is employed to fabricate ternary Fe/Co/Zn (FCZ) composites with precisely controlled composition and architecture. Specifically, the topological structure progressively evolves from the inheritance of leaf-like precursors to hierarchical self-assembly and to final reconfiguration. Introducing Fe into the original Co/Zn bimetallic system progressively suppresses the Co₃ZnC phase while promoting the formation of the Fe-Co solid solution and amorphous ZnO. The construction of multiple heterointerfaces and high-density defects within nitrogen-doped carbon substrates facilitates the coupling effect of multiple polarization loss mechanisms. This synergistic effect induces an anomalous dielectric behavior, characterized by attenuated polarization relaxation peaks concurrent with enhanced polarization response. Consequently, the optimized FCZ4 demonstrates exceptional electromagnetic wave absorption performance, featuring an ultra-low reflection loss of −84.41 dB and an ultra-broad bandwidth of 6.08 GHz. Gradient regulation of Fe content enables the realization of tunable frequency response characteristics spanning the low-to-high frequency range. This work establishes a generalized phase-structure-dielectric correlation model, offering new insights into tailorable electromagnetic attenuation in multi-metallic systems.

Carbon fibre, renowned for its exceptional strength-to-weight ratio, plays a pivotal role in advancing clean technologies such as renewable energy systems and lightweight transportation, thereby contributing to a more sustainable economy. However, the production of carbon fibres and their composites presents a paradox: while it enables significant environmental benefits through various end-use applications, the manufacturing processes are highly energy-intensive and reliant on synthetic resins, which are often non-recyclable. This review critically examines the sustainability of carbon fibre through a comprehensive analysis of life cycle assessment (LCA) studies, highlighting the environmental and economic impact of carbon fibre composite production, use, and recycling. Additionally, the paper explores the latest advancements in using recyclable polymer resins, and remanufacturing and the alignment methods of recycled carbon fibres, which offer promising pathways for improving the circularity of carbon fibre composites. By critically evaluating these aspects, the paper aims to provide insights into the current challenges and potential solutions for making carbon fibre a truly sustainable material in the context of a clean economy.