Nature achieves remarkable multifunctionality by integrating chemically dissimilar phases into hierarchically organized architectures. Inspired by this principle, we develop a simple and universal strategy to construct bio-composite aerogels by incorporating trivalent metal chlorides (MCl3) into biopolymer chitosan (CTS) matrices. Coordination-driven assembly in aqueous media enables the direct formation of metal ion-coordinated chitosan (CTS-M) aerogels without external acids or additional crosslinkers. These aerogels exhibit reversible brittle-to-flexible transitions under humidity stimuli, together with exceptional mechanical resilience, enabling self-adaptive thermal insulation under temperature extremes. Upon pyrolysis, the same precursor is converted into conductive carbon-metal oxide (C-M2O3) aerogels, where metal oxide nanocrystals are embedded within an interconnected carbon framework. This structural integration couples a continuous electron-transport network with redox-active domains, thereby promoting charge-transfer and increasing accessible storage sites. As a representative example, the C-V2O3 cathode for aqueous zinc-ion batteries (ZIBs) delivers excellent energy-power performance (656 Wh kg-1 at 200 W kg-1, 178 Wh kg-1 at ∼20 000 W kg-1) with 85% capacity retention after 10 000 cycles, outperforming previously reported carbon-metal oxide systems. By linking adaptive thermal regulation and electrochemical energy storage through a single precursor-to-function pathway, this work establishes an evolution-driven aerogel design paradigm for next-generation multifunctional materials.

Organic-inorganic hybridization is an effective strategy to enhance the mechanical properties of silica aerogels. However, their fabrication typically relies on supercritical or freeze-drying methods, which result in high production costs. In this study, polyimide-hybrid reinforced silica composite aerogels were successfully fabricated via a simple ambient pressure drying method. A controlled variation of polyimide content (5-30 wt %) enabled the transformation of the composite aerogels from transparent monoliths to white structures. Experimental results demonstrate that increasing the PI content promotes the formation of extended linear polyimide chains within the silica network, markedly enhancing the compressive strength and Young's modulus of the composite aerogels. Meanwhile, the thermal conductivity of these composite aerogels remained low. Most notably, the composite aerogel with 5 wt % PI exhibited a thermal conductivity of 22.34 mW & centerdot;m(-1)& centerdot;K-1, visible light transmittance exceeding 70%, a limiting oxygen index of 42.6%, and a compressive strength of 0.7 MPa, demonstrating its potential as an excellent transparent and thermal insulation daylighting material. The composite aerogel SP30 exhibited a compressive strength and Young's modulus of 2.15 and 8.55 MPa, respectively, outperforming previously reported SiO2/PI composites. Finally, an in-depth analysis of the growth mechanisms and structures of composite aerogels with varying PI contents was conducted. This study provides a promising technical route for the low-cost fabrication of high-performance organic-inorganic composite aerogels. The proposed composite aerogels hold considerable promise for next-generation building energy-saving materials, especially in transparent insulation and thermal management applications.

Polymethacrylimide (PMI) foam is a widely used core material in lightweight sandwich structures, yet its mechanical behavior under elevated temperatures (typical co-cure molding conditions up to 120 °C) remains insufficiently understood from a microstructure-informed perspective. This study establishes a temperature-dependent, microstructure-informed experimental-computational framework to quantitatively link cell-wall properties to macroscopic yield surfaces across temperatures from 25 °C to 120 °C. Elevated-temperature nanoindentation reveals that the cell-wall elastic modulus decreases from 5752 to 3562 MPa and yield stress from 97.2 to 61.6 MPa, while the hardening exponent increases from 0.10 to 0.55, evidencing a brittle-to-ductile transition. High-fidelity finite element simulations based on μ-CT reconstructed microstructures capture the evolution of deformation mechanisms: at near-ambient temperatures (25-40 °C), plastic hinges and shear bands dominate; at elevated temperatures (80-120 °C), uniform plastic flow emerges and shear band formation is suppressed. Intra-cell gas pressure, modeled as fluid cavities, reduces the peak equivalent plastic strain by 3-4%, acting as a microscopic passive damper that synergizes with thermal softening to promote uniform deformation. Using a statistically equivalent Voronoi model validated against uniaxial experiments, multiaxial simulations (over 100 loading paths per temperature) are performed to construct initial yield surfaces in the σm-σe plane. The elliptical yield surfaces, centered on the hydrostatic axis due to initial isotropy, exhibit tension-compression asymmetry and contract toward the origin with increasing temperature. This physically based framework quantitatively bridges temperature-dependent microstructural mechanisms to macroscopic yielding, providing predictive capability for thermal-mechanical processing of PMI foam sandwich structure.

Alumina aerogels are promising candidates for high-temperature thermal insulation, yet simultaneously achieving high compressibility and high-temperature thermal stability remains challenging. In this work, phase field simulations of three representative aerogel skeletons reveal that skeleton morphology and density are the key determinants of sintering resistance. Guided by these insights, we developed a chitosan-templated synthesis route that enables the formation of a nanofibrous alumina structure. Coordination between aluminum ions and chitosan chains directs the growth of alumina along the chitosan nanofibrils, and a nanofibrous alumina (NFA) aerogel was obtained after gelation, ethanol supercritical drying, and template removal. The resulting NFA-5 aerogel exhibits a high specific surface area of 532 m2/g. After compositing with basalt fiber felt and mullite fiber felt, the resulting composites achieves maximum uniaxial compressive stresses of 5.7 MPa and 2.8 MPa at 80% strain, respectively, together with low thermal conductivities of 0.022 and 0.026 W/(m center dot K). The fibrous structure effectively suppresses the high-temperature sintering of alumina, enabling the material to retain a high specific surface area of 230 m2/g and a low linear shrinkage of 11% even at 1200 degrees C. This strategy provides a viable route to control sintering behavior, and enhance the structural stability of alumina aerogels for hightemperature applications.

Despite their promise as lightweight, ultralow-thermal-conductivity thermoelectric (TE) materials, aerogels have been largely limited to p-type organic or carbon-based systems with modest zT < 0.1 at 300 kelvin. Here, we propose a stepwise synthesis strategy that yields the first inorganic aerogel exhibiting state-of-the-art n-type TE performance. Optimized aerogels with 95% porosity exhibit a high power factor of 34.8 microwatts per meter per square kelvin and an ultralow thermal conductivity of 0.061 microwatts per meter per kelvin, resulting in zT values of 0.17 at 300 kelvin and 0.24 at 383 kelvin. A vertical TE generator prototype with six TE-aerogel legs achieves a gravimetric output power of 76 microwatts per gram under a ΔT of ~60 kelvin. To address brittleness, a polyimide-encapsulated aerogel with bioinspired architecture was developed, achieving a high compressive strength to 1.4 kilopascals while maintaining excellent TE performance. This work establishes a generalizable method for designing high-performance flexible inorganic aerogels, opening more possibilities for lightweight wearable energy harvesting technologies.

Multifunctional packaging materials made from biomass resources are key to achieving packaging storage and environmental friendliness. The aim of this study is to prepare high-performance cellulose-based packaging films to improve the high-value utilization of cellulose resources. In this paper, the blended films of sodium carboxymethyl cellulose (CMC) and poly(vinyl alcohol) (PVA) were used as the substrate and doped with tannic acid (TA)-coated cellulose nanocrystals (CNC@TA). Then, zinc ions (Zn2+) were decorated on the film surface by adsorption self-assembly. The modified films (Z-CPC@T5 films) were prepared with excellent mechanical properties (tensile strength and elongation at break of 73.85 MPa and 19.68 %, respectively). Meanwhile, the presence of CNC@TA provided the films with UV and oxidation resistance. In addition, the zinc coating formed on the film surface conferred water resistance, hydrophobicity, and structural stability (water contact angle up to 97.09°). The modified films also showed excellent antimicrobial and water-vapor barrier properties. The modified films preserved cherries for at least 16 days with a quality retention of 87.20 %. In addition, cytotoxicity tests confirmed the non-toxic properties of the modified films. Overall, this strategic fusion of internal and external dual crosslinking expanded the application potential of active packaging materials.

Carbon fiber reinforced plastic (CFRP) T-joints are widely used in aerospace structures, and the curing quality and peel resistance of their adhesive layer remain challenging. Herein, a novel carbon nanotube (CNT) capacitive sensor is proposed to in situ monitor and mechanically reinforce the adhesive layer of CFRP T-joints. CNT sensors with volcano-shaped convex holes (CHs), planar holes (PHs), and non-holes (NHs) were prepared and integrated into the adhesive layer of CFRP T-joints. The results show that CNT sensors possess stable capacitance signals and low signal-to-noise ratios. During the curing process, the capacitance change (Delta C/C-0) versus time curves of specimens containing CNT sensors exhibit a unimodal characteristic. Compared with the specimens containing PH and NH, the maximum Delta C/C-0 of specimens containing CH increases by 82% and 66%, respectively. Meanwhile, the maximum Delta C/C-0 increases with increasing pressure or temperature. Moreover, during the peel testing, compared with specimens containing PH and NH, the average Delta C/C-0 of specimens with CH respectively increases by 112% and 194% at damage initiation. The ultimate load of T-joints containing CH, PH, and NH, respectively increases by 13.03%, 2.8%, and -5.7% compared with the base T-joint. Therefore, the CH capacitive sensor with volcano-shaped array holes shows advantages of structural-functional integration.

Polyimide aerogels are renowned for their exceptional thermal stability and low dielectric constant but are constrained by excessive rigidity, limiting their application in flexible microelectronics, aerospace systems, and antenna technologies. This study presents novel hierarchical aerogels featuring dynamic reversible physical entanglements - layer-cake-like and cheese-like structures - derived via a solvent-tunable bubble templating method. These hierarchical structures enable unrestricted molecular chain mobility during deformation, efficiently mitigating stress concentration. The dynamic reversible entanglement network facilitates efficient stress redistribution under compression or torsion, while disentangled segments reform during recovery, significantly enhancing mechanical toughness. The layer-cake-like aerogel withstands compressive strains up to 80%, retains structural integrity over hundreds of loading-unloading cycles, and achieves a toughness of 2099.33 kJ.m-3. Concurrently, the cheese-like aerogel exhibits shape memory behavior. The aerogels developed in this work not only exhibit superior resilience but also demonstrate excellent electromagnetic wave transmission properties. These advancements establish a framework for designing resilient, multifunctional aerogels, paving the way for future flexible electronic materials.

Fiber reinforced silica aerogel is the most commercially used aerogel material at present, but its mechanical property is still low due to the poor interface between fiber and aerogel. Herein, a high-performance silica composite aerogel with mullite whisker growth on aluminum silicate fiber surface were prepared by combustion method. Due to the introduction of mullite whiskers, the compressive strength of ASF/MW/SiO2 is 2.45 MPa, which is 150 % higher than that of ASF/SiO2. The compression process of the composite aerogel was analyzed in detail. The composite aerogel remains lightweight (0.216 g/cm3) and a low thermal conductivity (0.029 W/ (m center dot K)). Through the butane spray gun combustion experiments, 10 mm ASF/MW/SiO2 material can isolate temperatures up to 1000 degrees C and maintain good structural stability. Finally, the growth mechanism and advantages of combustion technology to produce ASF/MW/SiO2 were discussed. The ASF/MW/SiO2 material is lightweight, excellent compressive and high-temperature insulation properties, and has potential application value in extreme temperature environments such as aerospace thermal protection. This research provides a new technical route for the preparation of aerogel materials with low thermal conductivity, high temperature and high mechanical properties.

Polymethacrylimide (PMI) foam is extensively utilized in lightweight sandwich structures yet lacks a reliable global yield surface for design guidance. This study presents an integrated experimental-computational framework for PMI foam yield surface construction. Cell-wall properties were precisely determined via nanoindentation combined with an inverse identification approach employing finite element modeling, machine learning, and traversal algorithms. A microstructure-informed Voronoi model, generated from micro-CT data and incorporating gas-filled cells with cell-wall properties, was developed for PMI foam simulation. Following validation against experimental uniaxial stress-strain curves, the model was subjected to multiaxial simulations under varying loading ratios to acquire comprehensive yield points for global yield surface construction, which was verified by equivalent biaxial tensile/compressive tests. The results show the cell-wall possesses 10.49 % higher Young's modulus and 8.00 % greater initial yield stress than PMI matrix. Uniaxial microstructural analysis reveals intracellular gas enhances compressive strength by 6.33 % while minimally affecting tensile behavior. Notably, the yield surface shows distinct tension-compression asymmetry in stress/strain plane, near-perfect ellipsoidal fitting (R2 = 0.998) in principal strain space, and excellent predictive accuracy with equivalent biaxial test errors of -4.06 % (tension) and + 9.85 % (compression). These results provide theoretical foundations for safety optimization and structural design of PMI foam in engineering applications.

The limited capacity of conventional carbon electrode materials hinders the practical application of capacitive deionization (CDI). Hence, it is imperative to develop electrode materials with high sodium ion adsorption and reliable stability to facilitate the construction of hybrid CDI (HCDI) systems. Notably, NaTi2(PO4)3 (NTP) has received significant attention due to its high capacity and rapid transportation ability of sodium ions. However, the poor electrical conductivity and limited electrolyte contact area of NTP have prevented further improvement in its deionization capacity. Herein, we report a seed strategy to synthesize NTP/carbon aerogel (CA). P25 was used as a seed crystal to prepare TiO2/CA via the sol-gel method and supercritical CO2 drying. NTP/CA was then obtained from TiO2/CA by hydrothermal synthesis and calcination. This strategy preserved the rational network skeleton of CA and endowed NTP/CA with a high specific surface area of 420 m2/g. The enhanced electrical conductivity provided by CA yielded a remarkable salt adsorption capacity of 43.3 mg/g in a 500 mg/L NaCl solution and a stable cycle desalination capability. This work provides a new perspective for constructing threedimensional, highly efficient and stable HCDI electrode materials.

Aerogels are ultra-light, nanoporous solid materials characterized by extremely high porosity, with up to 99 [...]

Nitrogen-oxygen co-doped porous carbon microspheres were synthesized through hydrothermal and carbonization processes using polyimide (PI) as the carbon precursor and a nitrogen-oxygen source. ZIF-8 was also used as the template. When the carbonization temperature reached 800°C, the porous carbon microspheres displayed a unique 3D sea urchin-like morphology, a high specific surface area (782.3 m2/g), and good nitrogen and oxygen doping contents (6.62 and 11.92 at

Sol-gel nano-silica antireflective (AR) coatings with moisture resistance are widely used for optical elements, such as potassium dihydrogen phosphate (KDP) crystals, but their mildew resistance is often disregarded. This work reports a double-layer AR coating with moisture resistance and mildew resistance for KDP crystals. A polydimethylsiloxane-modified dense silica coating and a quaternary ammonium salt (QAS) modified nanoporous silica coating are selected as the bottom layer and top layer, which effectively serve as a moisture barrier and an antireflection layer, respectively. The coated KDP crystal shows excellent antireflection properties with a maximum transmittance of 99.1% at 532 nm. Perfluorooctyltriethoxysilane vapor treatment is performed further to improve the resistance to moisture and mildew. The resultant double-layer coating exhibits superior moisture resistance with almost no change in optical transmittance after a 3-month exposure to a high-humidity environment. The introduction of QAS and hydrophobicity in the top layer provides exceptional resistance against mildew, achieving an antimicrobial rate of 99.9% against E. coli and A. flavus. Moreover, the laser-induced damage threshold reaches 17.0 J cm-2 (355 nm, 4.5 ns). This work imparts moisture resistance and mildew resistance to AR coatings, providing valuable insights for designing multifunctional AR coatings on optical components.

Polyvinylpolymethylsiloxane (PVPMS)/polydimethylsiloxane (PDMS) copolymer aerogels were synthesized via consecutive radical polymerization and cohydrolytic polycondensation of vinylmethyldimethoxysilane and dimethyldimethoxysilane, followed by supercritical drying or ambient pressure drying. The resultant PVPMS/PDMS copolymer aerogels exhibit a highly porous, tunable triple-network structure consisting of interlinked hydrocarbon polymers, PVPMS and PDMS. These aerogels display superhydrophobicity (151°), low density (109 mg cm-3), low thermal conductivity (29.8 mW m-1 K-1), and adjustable pore structure. The combination of good machinability, low thermal conductivity, excellent compressive elasticity and bending flexibility, and efficient organic solvent adsorption gives these aerogels broad application prospects in thermal insulation and oil-water separation. In addition, PVPMS/PDMS/carbon nanotube (CNT) composite aerogels were obtained by incorporating the conductive CNTs, followed by vacuum drying. The resultant PVPMS/PDMS/CNT composite aerogel exhibits high sensitivity with a broad pressure sensing range in strain and pressure sensing applications.

Metal oxide aerogels, inorganic cousins of the highly commercialized metalloid oxide silica aerogels, exhibit distinct properties specific to each type. Nevertheless, they share a common challenge with silica aerogels-brittleness and low mechanical strength due to their particulate necklace-like structure. In contrast, polymer aerogels often boast significantly enhanced mechanical properties thanks to their nanofibrillated networks. To enhance the mechanical properties of metal oxide aerogels, the metal oxide formation with a polymeric nanostructure is micro-templated. This method transforms the necklace-like particulate microstructure of metal oxide aerogels (e.g., Al2O3 Cr2O3, and Fe2O3) into a polymer-like nanobelt structure. Remarkably, even after removing the polymer template through calcination at 600 degrees C, the nanobelt structure remains intact. These metal oxide nanobelt (MNB) aerogels exhibit exceptional compressibility while retaining their mesoporous structure. As a demonstration, the resulting Al-MNB aerogel can withstand compression up to 80% strain without fracturing while preserving its porous nanobelt structure and a high specific surface area of 228 m2 g-1 and a pore volume of 0.7 cm3 g-1 after heat treatment at 1300 degrees C. This work introduces an innovative strategy for creating a distinctive polymer-like nanobelt microstructure, paving the way for novel applications of metal oxide aerogels with unique structures and enhanced performance. Microtemplating metal oxide aerogels into a polymer-like nanobelt structure results in a material with exceptional compressibility while retaining its mesoporous structure even after high-temperature calcination. Al-metal oxide nanobelt aerogel can withstand compression up to 80% strain without fracturing, while preserving its porous nanobelt structure and maintaining a high specific surface area of 228 m2 g-1 after calcination at 1300 degrees C. image

Moisture-proof coating is essential to protect humidity-sensitive optical or electronic components. Generally, the moisture resistance of sol-gel coating depends primarily on the surface chemical composition and the internal microstructure of the coating. In this work, experimental studies were conducted on sol-gel silica coatings with different surface free energy (SFE) and pore volumes to elucidate the effect of the two contributing factors on moisture resistance. The results show that these two factors are both independent and synergistic. As the SFE or pore volume of the coating decreases, the moisture resistance is improved. However, when the SFE is reduced to around 10 mJ/m2, the silica coatings exhibit superior moisture resistance and are independent of the microstructure. Furthermore, once the pore volume of coatings is reduced to approximately 0.5 cc/g, the coatings exhibit notable moisture resistance, regardless of their surface chemical composition. This work provides fundamental insights and valuable recommendations for the design and fabrication of sol-gel moisture-proof coatings, with broad applicability in moisture-sensitive electronic components, photovoltaic cells, and cultural relics protection, among others.

Using sulfide solid electrolytes is considered a viable strategy for developing all-solid-state lithium metal batteries. However, the parasitic interfacial reactions between the electrolyte and the lithium anode and lithium dendrite growth inside the electrolyte have not been completely resolved. Herein, we proposed a multi-step constant-current charging/discharging (MCCCD) protocol on the basis of the regulation of a series of Li7-xPS6-xClx (x = 1.0, 1.3, 1.5, and 1.7) electrolytes with different chloride contents to reduce the damage to the lithium metal anode and further improve the cycle performance of the all-solid-state battery. The chlorine content has a significant impact on the stability of the Li/solid electrolyte interface. Specifically, the highest critical current density and lowest polarization were obtained for moderate chlorine content (Li5.5PS4.5Cl1.5), which could be attributed to the effect of LiCl. Moreover, the multi-step constant-current charging/discharging (MCCCD) protocol can effectively alleviate the interface deterioration without any interface modification. The full cell with MCCCD maintains a reversible capacity of 140.1 mA h g-1, with a capacity retention of 77.1% after 300 cycles. This work may provide a new strategy to enhance the electrochemical performance of all-solid-state lithium metal batteries. A multi-step constant-current charging/discharging (MCCCD) protocol was proposed to reduce the damage to the lithium metal anode and further improve the cycle performance of the all-solid-state battery.

A convolutional neural network (CNN) model by deep-learning single channel data from a serpentine carbon nanotube sensor (S-CNT) with gradient distributed CNTs is proposed for locating deformation/damage in carbon fiber reinforced plastic (CFRP). The real-time resistance-time data caused by bending deformation of CFRP embedded with S-CNT are encoded into more discriminative 2D images for training the CNN. The results show that an accurate deformation localization within 1.5 mm for the trained positions can be obtained. Moreover, static-indentation loading reveals that the CNN model also has high localization accuracy for new deformation/ damage locations in CFRP, with an error of less than 5.5 mm.