Advanced Composites and Hybrid Materials最新文献

The development of high-performance electromagnetic wave-absorbing materials that combine cost efficiency and environmental sustainability remains a critical challenge in the fields of functional materials and stealth technology. Although the magnetoelectric coupling strategy has emerged as an important approach for designing high-performance absorbers by introducing magnetic loss and improving impedance matching, its ability to enhance absorption bandwidth remains limited, thereby restricting its application in scenarios requiring broadband absorption. To address this issue, this study proposes an innovative strategy for fabricating a hierarchical composite absorber derived from waste-based activated carbon spheres (ACSs). Inspired by natural biological structures, a sweet potato leaf-inspired electromagnetic wave absorber (SPL) has been designed. Leveraging electromagnetic wave localization theory and machine learning-assisted structural optimization, the resulting SPL successfully maximizes the localization of electromagnetic waves within the material distribution region. This leads to exceptional electromagnetic wave absorption performance, achieving a reflectivity below -10 dB across the entire 3–50 GHz frequency range at a matching thickness of only 10 mm. Simultaneously, owing to the inherent absorption characteristics of the activated carbon base, the composite retains its excellent capacity for adsorbing harmful gases. This work not only provides a high-performance, low-cost, and multifunctional electromagnetic wave absorber but also offers valuable insights into the value-added reuse of waste resources and the rational design of bio-inspired structures for advanced electromagnetic protection applications in both military and civilian architectural domains.

Corrosion is a persistent challenge in engineering, causing significant degradation of metallic materials across industries. Layered double hydroxides (LDHs), a versatile class of two-dimensional materials, offer promising solutions for corrosion protection owing to their exceptional properties, such as anion capacity, anion exchangeability, and barrier resistance. Despite comprehensive reviews on the preparation of LDH powders or films and their applications in various corrosive environments, there has been no thorough examination of corrosion protection enhancement measures taken to address the deficiencies of LDH films grown in situ on metal surfaces. This review fills that gap by introducing the fundamental approaches and methodologies for growing LDH films directly on metal substrates, including strategies for structural design and surface modification to optimize protective performance. We identify the key challenges and issues that currently limit the long-term protective performance of these films. Subsequently, we examine advanced structural regulation and surface engineering techniques, including parallel growth, pore sealing, surface wettability regulation, active protection, and integrated methods, to enhance their durability and overall corrosion resistance. Finally, we highlight emerging research directions for translating these concepts into innovative and robust LDH-based films. By consolidating current knowledge on the structure and surface engineering of in-situ grown LDH films, this review aims to guide the rational design and development of pioneering corrosion protection materials.

Ferroelectric materials are highly promising for dielectric properties in the field of flexible printed electronics as varactors due to their non-linear behavior. For the utilization in flexible films, composite inks consisting of ceramics and polymers are of great interest with BST/P(VDF-TrFE) being one of the promising choices. Herein, we are developing printable inks and studying the influence of ferroelectric ceramics (BST) and ferroelectric polymers (P(VDF-TrFE)) as well as non-ferroelectric ceramics (Al₂O₃) and non-ferroelectric polymers (PMMA). We were able to fabricate fully inkjet-printed BST/P(VDF-TrFE), BST/PMMA and Al₂O₃/P(VDF-TrFE) varactors with dielectric layer thicknesses between 1.24 and 1.70 μm. Dielectric investigations show that BST/P(VDF-TrFE) greatly outperforms the other systems and reaches a maximum tunability of 12.80% @40 V with a high Q factor of 27.7.

Zirconium based MOFs demonstrate potential for ecofriendly modification of collagen fibers. However, achieving high utilization efficiency of zirconium ions remains challenging. Herein, a novel boronate ester functionalized MOF (Zr-TB) with pH-dependent structural stability is disclosed. It maintains structural integrity under neutral conditions but decomposes under acidic conditions below pH 4.0. Based on this, a novel modifier for collagen fibers is developed by loading zirconium complex (ZTA) into Zr-TB. This system enables controlled release of ZTA, thereby preventing excessive binding between zirconium ions and collagen fibers. EDS analysis confirms the uniform distribution of zirconium ions in the modified collagen fibers, resulting in excellent hydrothermal stability characterized by a shrinkage temperature of over 80 °C. DFT calculations reveal that the zirconium cluster complex generated from the decomposition of Zr-TB can also effectively bind to the -COOH of collagen fibers, thereby significantly improving the utilization efficiency of zirconium ions. Notably, after ball milling, the modified collagen fibers serve as an efficient catalyst for the Knoevenagel reaction and exhibit excellent cycling stability, maintaining a yield above 87% over five consecutive cycles, attributable to the uniform distribution of zirconium ions on the collagen support. Furthermore, the presence of -NH₂ on the collagen fibers effectively eliminates the need for additional alkaline catalysts. This work presents a highly efficient strategy for modification of collagen fibers and highlights the promising potential of collagen fibers as carriers for organic synthesis catalysts.

A covalently co-networked poly(vinylmethyldimethoxysilane)/polyvinylpyrrolidone (PVMDMS@PVP) aerogel scaffold enables in-situ growth of UiO-66-NH₂ and grafting of 1-methylacetamido-3-methylimidazolium bromide ([MAmim]Br), forming a monolithic catalyst for integrated carbon dioxide (CO₂) capture and cycloaddition reaction. Tuning PVP content (5–20 wt %) during sol–gel synthesis yields a hierarchically porous network (> 1,000 m²·g^–1) that resists collapse under solvothermal conditions. Solvothermal crystallization within the network produces uniformly dispersed UiO-66-NH₂ (~ 34 wt %) without pore blockage, and ionic liqud (IL) grafting introduces dual sites for CO₂ adsorption and epoxide activation. The composite achieves 2.8 mmol g^–1 CO₂ uptake at 25 °C and promotes solvent- and co-catalyst-free cycloaddition of allyl glycidyl ether (AGE) at 120 °C, 0.6 MPa CO₂ to > 99% conversion and selectivity with 0.151 mol % catalyst loading. Ten consecutive adsorption–desorption and reaction cycles retain > 97% of activity and structural integrity. An apparent activation energy of 37.5 kJ mol^–1 (vs. 47.8 kJ·mol^–1 for UiO-66-NH₂-IL) highlights accelerated kinetics. Exceptional water tolerance and multi-cycle stability underscore its potential as a scalable platform for practical CO₂ valorization.

The development of efficient photocatalysts for water purification is vital to mitigate the global clean water shortage. In this study, a heterostructured photocatalyst was synthesized by incorporating Ti₃C₂-MXene Quantum Dots (MQDs) into an iron-based metal-organic framework (NH₂-MIL-88B(Fe) MOF) to enhance photocatalytic activity. The prepared composites were systematically characterized by XRD, FTIR, TEM, FE-SEM, UV–Vis DRS, BET, XPS, and PL analyses. Compared with the pristine MOF, the results revealed markedly enhanced visible-light absorption and significantly reduced charge-carrier recombination, confirming the successful integration of MQDs into the MOF heterostructure. The degradation of methylene blue (MB) under visible light irradiation was used to assess the photocatalytic performance. While the pristine MOF showed high adsorption (73.01%) but negligible photocatalytic activity, and bare MQDs exhibited only 23.33% degradation, the 50MQDs/MOF composite achieved a remarkable photocatalytic efficiency of 62.97%. This represents a multiplicative enhancement and underscores the critical role of the heterostructure in unlocking the inherent photocatalytic potential of the MOF. Radical scavenging experiments confirmed that electrons (e⁻) and superoxide radicals ((:{O}_{2}^{{bullet:}-})) are the dominant reactive species in the degradation process. The enhanced activity was attributed to the synergistic interaction between MOF and MQDs, resulting in superior adsorption capacity, more efficient charge separation, and improved electron transfer. These findings indicate that MQD/MOF heterostructures hold strong promise as sustainable photocatalysts for real-world wastewater treatment involving organic pollutants.

Additive friction extrusion deposition (AFED) has emerged as a promising solid-state manufacturing method for 3D printing of high-strength aluminum-based alloys and composites. However, the occurrence of abnormal grain growth in the AFED Al-Cu-Mg alloys during post-processing solid solution heat treatment often leads to significant degradation in tensile strength and ductility. To address this issue, 1.5 vol% carbon nanotubes (CNTs) were incorporated into 2009Al to form composite feedstocks for AFED. Microstructural characterization revealed that, in addition to CNTs, dispersed MgAl₂O₄ nanoparticles formed by the reaction between the introduced oxygen and matrix alloy were also observed in the AFED CNT/2009Al. Quantitative analysis showed that the presence of 3.3 vol% dispersed nanoparticles led to a high pinning parameter of 0.71, situating the AFED CNT/2009Al within the no grain growth zone of the Humphreys’ grain growth model. As a result, the AFED CNT/2009Al exhibited significantly enhanced grain thermal stability and tensile strength. Different from the conventional strategy that increases strength by grain refinement, the strength of the AFED CNT/2009Al was further enhanced by increasing the tool rotation rate during AFED for obtaining a moderately coarser grain structure with a higher proportion of intragranular nanoparticles. The ultimate tensile strength and ductility of the AFED CNT/2009Al were increased from 562 MPa and 5.7% to 573 MPa and 13.5%, respectively, attributable to significantly increased strain hardening rates and alleviated strain concentration. These findings offer a new pathway for developing advanced nanocomposites with an exceptional strength-ductility synergy.

Flexible electronic fibers that combine scalable manufacturability with multimodal physiological sensing remain challenging due to the conflicting requirements of conductivity, porosity, mechanical compliance, and environmental robustness. Here an in-situ thermally induced phase separation (TIPS) strategy integrated into thermal fiber drawing (TFD) was proposed to produce continuous flexible and stretchable porous graphene-polymer nanocomposite fibers with independently tunable pore architecture and electrical properties. Starting from a solvent-borne graphene/polyvinylidene fluoride slurry within an elastomeric cladding, our process yields tens of meters of fiber from a compact preform while accommodating high graphene loadings, enabling a percolated conductive network embedded in a phase-separated matrix. The fiber exhibited a conductivity of (1.35 ± 0.96) × 10^− 3 S m^− 1, reflecting a moderately percolated network formed within the polymeric matrix that balances electrical transport and structural porosity. The resulting fibers operate as multimodal wearable sensors, namely, a temperature sensor with a stable output and high temperature sensitivity with a negative temperature coefficient of resistance (TCR = 0.558 °C^− 1), a pressure sensor with reliable cyclic response, and a dry-electrode cardiovascular data monitoring interface whose impedance/phase behavior closely matches commercial electrodes at low frequencies and captures fundamental features on human skin. The removable elastomeric cladding imparting water resistance supports textile integration and stable operation under humid exposure. This single-step, generalizable manufacturing route decouples porosity and conductivity to co-design fiber mechanics and device performance, advancing scalable fiber-/textile-grade platforms for continuous health and motion monitoring.

Gut-to-brain bioelectronic materials represents an emerging paradigm for non-invasive neuromodulation at brain. However, conventional carriers suffer from poor acid stability and limited permeability across intestinal epithelium and the blood–brain barrier (IEB and BBB). In this study, a transferrin (Tf)-coated conductive metal–organic framework antenna (Tf-cMOF) doubles as gut-to-brain ROS-scavenger and brain-penetrating enhancer for traumatic brain injury (TBI) treatment. Receptor-mediated transcytosis of Tf-cMOF allows therapeutics to be delivered across IEBs and reside in damaged TBI; the induced current generated by an external high-frequency magnetic field (HFMF) boosting permeability further promotes the particles-penetrating into TBI. The excellent intrinsic ROS-scavenging ability of Tf-cMOF, combined with the anti-inflammatory agent Probucol (P) loaded within it, effectively reduces inflammation during the early stage of TBI. In the secondary stage of TBI, under HFMF exposure, Tf-cMOF generates magnetoelectric coupling and local electric stimuli, promoting neuromodulation, neural differentiation and neural regeneration in both neural stem cells (NSCs) and in vivo. In vivo analyses further confirmed enhanced angiogenesis and neuronal infiltration around the TBI lesion, leading to functional recovery. This magnetoelectric Tf-cMOF demonstrates a promising route for gut-to-brain delivery of nano-antennas, establishing a versatile and wireless neuronal regeneration therapy.

Silver selenide (Ag₂Se) is a promising n-type thermoelectric material because of its excellent thermoelectric performance near room temperature, but conventional methods for fabricating bulk Ag₂Se require high temperatures and pressures making scalable production a challenge. Here, a facile and scalable strategy is presented for fabricating high-performance dense Ag₂Se_1.2 thermoelectric material by incorporating excess Se in solution-processed Ag₂Se powders. The excess Se facilitates liquid-phase-assisted grain growth during annealing at 623 K under ambient pressure, which greatly improves microstructural properties such as the grain connectivity and bulk density. In experiments, Ag₂Se_1.2 exhibited a high-power factor and reduced lattice thermal conductivity leading to a maximum figure of merit of 0.927 at 393 K. The shape-conformable nature of Ag₂Se_1.2 also allows for the fabrication of cylindrical thermoelectric generators with a stable output voltage and power at various temperature differences. This strategy is a highly effective approach for improving not only the thermoelectric and mechanical performances of Ag₂Se but also its applicability in curved or flexible energy harvesting devices.