Advanced Composites and Hybrid Materials最新文献

The ability to generate deceptive targets for self-concealment, much like a chameleon, has long captivated human imagination. However, traditional false-target techniques are typically confined to a single spectrum, limiting their usefulness across heterogeneous environments. In order to create deceptive targets that are simultaneously effective in visible, infrared and microwave spectra, we propose a multi-spectral compatible camouflage metasurface that can be coated on the target object, akin to an advanced digital camouflage net. In the visible spectrum, a synthetic deceptive-target image is projected by overlaying a high-resolution color print on an optically transparent substrate. In the infrared spectrum, a deceptive thermal signature is tailored by patterning low- and high-emissivity pixels. In the microwave spectrum, a deceptive radar signature is crafted by complex-amplitude holography based on the Huygens–Fresnel principle. As verification, the multispectral compatible camouflage metasurface is fabricated and measured, and all the results convincingly demonstrate our design. Encouragingly, this multispectral deceptive-target metasurface offers a route toward integrated camouflage systems with potential applications in building technologies, environmental sensing, and communications.

State-of-the-art 5-hydroxymethylfurfural electrooxidation typically requires a highly alkaline anolyte (e.g., 1 M KOH) to efficiently produce 2,5-furanedicarboxylic acid (FDCA). Scaling up of this technique is limited by excessive acid/base consumption and substantial organics degradation. These challenges can be mitigated by employing dilute electrolytes, provided that sufficient interfacial OH⁻ availability is maintained. Here, we present tip-enhanced electric field confinement to promote OH⁻ adsorption under mildly alkaline conditions (0.1 M KOH), thereby enhancing the activity of the electrocatalytic 5-hydroxymethylfurfural oxidation reaction (e-HMFOR). Morphology-tunable Mn-doped cobalt oxyhydroxide electrodes, MnCoO_xH_y-NNS (nanoneedles) and MnCoO_xH_y-NWS (nanowires), exhibit distinct and enhanced selectivity. Remarkably, the high-curvature tips of MnCoO_xH_y-NNS generate an enhanced electric field that enriches interfacial OH⁻ coverage. This feature expedites formyl group oxidation and strengthens the electrode’s electrophilicity, steering the oxidation pathway from 2-formyl-5-furanediformic acid (FFCA, 78.1% yield) to FDCA, 95.3% yield. Additionally, Mn doping in MnCoO_xH_y-NNS stabilizes the CoOOH phase and promotes OH* accumulation, enhancing e-HMFOR while suppressing competing water oxidation. Techno-economic analysis interprets that the improved e-HMFOR economy in 0.1 M KOH reduces the cost for feedstocks by ~ 67.9%. This work establishes a reliable strategy for customized electrocatalyst design in biomass oxidation under low alkalinity, eliminating the need for high-concentration electrolytes.

Lubricant-infused slippery organogels have emerged as promising materials in diverse practical applications. Nonetheless, the fabrication of lubricant organogels with surface microstructures remains challenging. Inspired by glassy plastics, we report a novel hot-pressing strategy for the reversible construction of microstructured surfaces for droplet manipulation. To achieve this, we design a tough, thermo-softening organogel by copolymerizing isobornyl methacrylate (IBMA) and perfluorooctylethyl acrylate (PFOEA), with perfluoropolyether incorporated as a lubricant. The PFOEA segments and lubricant provide excellent lubricity, endowing the organogels with self-cleaning, water harvesting and anti-icing properties. Furthermore, the rigid and solvophobic IBMA units stabilize the network at room temperature and impart exceptional thermo-softening behavior. Upon heating from 20 °C to 60 °C, the elastic modulus of the organogel decreases by over 1800-fold, from 67 MPa to 0.037 MPa. This significant thermo-softening property facilitates the straightforward fabrication of functional surface microstructures via hot-pressing, allowing the organogels to perform droplet manipulation tasks such as directional transportation, merging, and mixing. Furthermore, the microstructures can be easily erased and reformed by reheating. Collectively, this work presents a novel approach to constructing lubricant organogels with microstructured surfaces, offering significant potential for versatile applications.

The rapid accumulation of heat in microelectronic and energy-storage devices critically limits their performance, lifespan, and safety and necessitates the development of multifunctional polymer composites with high thermal conductivity and fire retardancy. Herein, we present a simple and scalable spray-drying and heat-treatment approach for the fabrication of heteroatom-doped spherical reduced graphene oxide (PN-S-rGO) microspheres, which simultaneously delivers P/N co-doping and tunable crystallinity. The unique spherical morphology of PN-S-rGO facilitates an isotropic heat-transfer behavior, resulting in a high ratio of through-plane to in-plane thermal conductivity (0.9) in an epoxy composite. Furthermore, incorporating PN-S-rGO with graphene nanoplatelets (GnPs) as hybrid fillers significantly improves the filler dispersion, promotes an isotropic orientation, and enhances interfacial interactions between the filler and epoxy matrix, leading to efficient thermal pathways and robust fire-retardant networks. The optimized hybrid composite (10 wt% GnPs and 40 wt% PN-S-rGO treated at 800 °C) exhibited outstanding thermal conductivities of 3.72 W/mK (in-plane) and 1.74 W/mK (through-plane), along with excellent fire retardancy, as characterized by a limiting oxygen index of 29% and 75% reduction in the peak heat-release rate compared to that of pure epoxy. These simultaneous enhancements are attributable to mechanisms that operate in synergy, including contributions from thermal bridging, catalytic carbonization, gas-phase radical quenching, and the formation of compact char layers. This study demonstrated a promising strategy for the development of high-performance polymer composites for use in advanced thermal-management and fire-safe applications in next-generation electronics, electric vehicles, and energy-storage systems.

Silicon-carbon composite anodes hold the promise to resolve the irreversible capacity fading of silicon in lithium-ion batteries but face persistent challenges dominated by unstable, physical interfacial contacts. Herein, a laser-directed covalent bonding strategy is developed to construct atomic-scale Si–N–C bridges between silicon suboxide (SiO_x) nanoparticles and a 3D nitrogen-doped graphene framework. Localized photothermal processing of polyimide-urea-SiO_x precursors on carbon-coated copper foil enables in situ integration of chemically anchored SiO_x within a conductive graphene network. The architecture achieves dual stabilization: (i) strong Si–N–C covalent bonds suppress interfacial cracking, while (ii) hierarchical porosity accommodates strain via elastic deformation. Critically, direct fabrication eliminates slurry-derived defects, ensuring structural integrity and minimized interfacial impedance. The optimized composite anode delivers 1826.4 mAh g^-1 at 0.1 A g^-1 and retains 91.3% capacity over 1000 cycles at a high current density of 2.0 A g^-1, demonstrating exceptional stability under high-rate operation. Mechanistically, density functional theory (DFT) reveals that Si–N–C bonding lowers lithium-ion (Li⁺) adsorption energy (–6.549 eV) and redistributes interfacial charge density, synergistically accelerating ion transport. This work provides atomic-scale insights into covalent interface design and establishes a scalable laser-processing strategy of composite anodes for durable high-energy-density batteries.

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Flexible and wearable electronics demand mechanically durable thermoelectric generators (TEGs) with reliable power generation. This study introduces a scalable two-step fabrication method for rugged thermoelectric elements. The approach involves forming a carbon nanotube (CNT) network by dip-coating porous substrates, followed by mechanical squeezing to densify the CNT network. This process enables the separate tuning of the CNT concentration (0.5 to 59 mg·cm^− 3) and the structural porosity (85% to 45%). The squeezed CNT sponge exhibited different electrical and thermal conductivities in response to the concentration and porosity values and ultimately achieved a thermoelectric figure of merit (zT) of 1.11 × 10^− 3 under optimal conditions. The fabricated eight-pair rugged TEG delivered a maximum output power of 12.25 µW at a 30.44 K temperature difference. The impact tests revealed that the rugged TEG maintains the power output, even after impacts of 1.00 J, and structurally withstands forces up to 2.49 J, unlike the conventional inorganic TEG, which fails completely at 0.053 J. Additionally, bending tests confirmed the TEG maintained a stable performance after 10,000 cycles, and water immersion tests demonstrated environmental stability, with the TEG retaining 73.7% of its initial performance after 1 day of immersion and recovering to 95.7% upon drying. This rugged TEG provides a practical approach to implementing thermoelectric energy harvesting in various wearable electronics and Internet of Things applications.

The performance of the hydrogen evolution reaction (HER) at the cathode in alkaline electrolysis can be compromised due to oxidation caused by the oxygen reduction reaction (ORR), led by oxygen gas crossover through the porous separator. In this study, we introduce N:NiFeP@FeNC, a highly efficient electrocatalyst for HER and ORR in an alkaline environment, featuring independent active sites for each reaction. N:NiFeP@FeNC demonstrated an overpotential of 78 mV to achieve a current density of 10 mA cm⁻² for HER and a half-wave potential of 0.88 V_RHE for ORR. Notably, the independent HER and ORR active sites effectively prevented oxidation of the HER active site during ORR durability tests. Through density functional theory (DFT) calculations, the mechanisms underlying HER and ORR on N:NiFeP@FeNC were elucidated, identifying key factors that enhance catalytic performance. The low activity of the HER active site (NiFeP) was attributed to the high energy barrier for *H₂O dissociation, while the low activity of the ORR active site (Fe–N–C) was related to delayed desorption due to excessively strong interactions between intermediates and the active metal centers. The incorporation of N atoms into the catalyst induced electronic structure reconfiguration in the Ni and Fe atoms, thereby facilitating electrochemical reactions. This study addresses a previously overlooked yet critical issue in alkaline electrolysis cathode research, providing a simple and effective strategy that highlights significance for future exploration.

Urgently, low-frequency (C-X band) electromagnetic absorption has emerged research hotspot along with 5G communication advancements and escalating military stealth demands. Single optimization strategies for cross-band systems face significant challenges. Particularly, the dispersion characteristics of dielectric constants exhibit marked variations across bands. Inspired by the skin’s "dermal-epidermal" thermoregulation system, we designed a "dermal-epidermal" binary interface to synergistically regulate cross-band electromagnetic impedance matching. Typically, "Dermis" interface polarization can effectively tune C-band impedance. And "Epidermis" designed plasmonics effectively tune X-band absorption intensity. By leveraging such binary synergy, the "dermal-epidermal" configuration achieved full X-band coverage and 2.48 GHz at the C-band (1.60 wt.%). And plasmonic-induced exchange resonance exhibits a distinct resonance peak in the X-band. This resonance peak plays a crucial role in reducing reflection loss (RL) and in increasing the effective absorption bandwidth (EAB). This work establishes a novel biomimetic configuration for lightweight, tunable low-frequency absorbers, advancing broadband electromagnetic material design.

Intrauterine adhesions (IUAs) is characterized by endometrial fibrosis that mediated by persistent inflammation. Hyaluronic acid (HA) in combination with umbilical cord mesenchymal stem cells (uMSCs) has been considered as promising strategy for intrauterine adhesions (IUAs) prevention. However, the rapid degradation and low adhesivity limited the further application in clinic. Herein, by introduction of methacrylic anhydride (MA) and mussel-inspired dopamine (DA) groups in HA, an injectable endometrium-adhesive and anti-inflammatory HMD hydrogel that could form sol–gel transition through visible light irradiation was innovatively designed, combined with uMSCs to regenerate endometrium and promote fertility for IUAs therapy. Adhesive HMD hydrogel can provide integrin binding sites to enhance paracrine activity of human umbilical cord mesenchymal stem cells (uMSCs), which subsequently promoted immunoregulation, cell proliferation and migration, and angiogenesis in vitro. HMD also significantly prolonged the retention of uMSCs in a rat model of IUAs, beneficial for immunoregulation by immune cell crosstalk, recruitment of macrophage to the injury sites, macrophage M2 polarization and activation of the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) signaling, thereby contributing to endometrial regeneration and reconstruction of fertility. Altogether, the novel adhesive and anti-inflammatory hydrogel may be a good alternative for the treatment of IUAs in clinic.

Carbon fiber-reinforced epoxy (CFRE) composites have become indispensable in high-performance structural applications in aerospace and automotive sectors due to their high strength-to-weight ratio and robust environmental resistance. However, they have a few limitations, such as inherent susceptibility to damage, limited reparability, and a lack of effective recyclability at the end-of-life. These limitations prevent their sustainable adaptation, perpetuating a linear economy paradigm. This comprehensive and critical review delves into the cutting-edge advancements made to address the limitations of CFRE composites. We rigorously evaluate the synergistic integration of nanomaterials and advanced interfacial engineering strategies designed to address these issues. The diverse nanomaterials, such as carbon nanotubes (CNTs), graphene nanoplatelets (GNPs), graphene oxide (GO), nanosilica, and nanoclay, together with advanced interfacial modification techniques, significantly improve the properties of CFRE composites. Furthermore, this review delves into the evolving field of various self-healing mechanisms, such as- reversible Diels-Alder (DA) bonds, microencapsulated healing agents, vascularized networks, aimed at autonomously restoring structural integrity and extending operational lifespan Finally, we also look in to the formidable challenge of end-of-life by analyzing emerging recycling methodologies and highlighting the paradigm-shifting vitrimer concept, which enables the reprocessability of traditionally non-recyclable thermoset matrices. By providing an insightful, forward-looking analysis of these interconnected multifunctional enhancements and sustainable pathways, this review not only synthesizes the state-of-the-art but also delineates potential research directions. We aim to lay a robust roadmap for the establishment of truly enhanced, autonomously reparable, and environmentally friendly CFRE composites, promoting a circular economy.