Transformation of oxide ceramic textiles from insulation to conduction at room temperature

Revolutionizing Inorganic Nanofibers: Bridging Functional Elements to a Future System

The advancement of intelligent ecosystems depends upon not only technological innovation but also a multidimensional understanding of material-world interactions. This theoretical transformation prompts increasing demands for multifunctional materials exhibiting hierarchical organization across multiple length scales. Inorganic nanofibers demonstrate potential in bridging the gap between microscale and macroscale through their three-dimensional architectures. However, their inherent brittleness, primarily resulting from inferior structural integrity poses, significantly limits their current applications. This critical limitation highlights the urgent necessity for developing fabrication strategies that simultaneously enhance the mechanical flexibility and robustness, ensuring reliable performance under extreme operational conditions. This comprehensive review systematically examines brittle mechanism fracture through multiscale analysis including molecular, nanoscale, and microscale dimensions. It presents innovative methodologies integrating simulation-guided structural design with advanced in situ characterization techniques capable of real-time monitoring under a practical stress-strain process. Furthermore, the discussion progresses to address contemporary challenges and emergent solutions in oxide nanofiber engineering, providing strategic insights for developing mechanically robust flexible systems with stable functional properties. Ultimately, this review examines the potential of inorganic nanofibers to overcome the limitations of nano powder materials and achieve their promising real-world applications.

Core-shell structured BN/SiO2 nanofiber membrane featuring with dual-effect thermal management and flame retardancy for extreme space thermal protection

With the rapid progress of aerospace frontier engineering, the extreme space thermal environment has brought severe challenges to astronauts' space suits, putting forward higher requirements for thermal protection materials. On this basis, a unique core-shell structured hexagonal boron nitride (h-BN)/silicon dioxide (SiO2) nanofiber membrane (HS) was prepared using the coaxial electrospinning method, of which both the thermal insulation SiO2 nanofiber cortex and the passive radiation cooling (PRC) h-BN nanofiber core make it a promising dual-effect thermal management material. Especially, when the amount of h-BN is 0.9 g, the resultant HS (HS0.9) exhibits astonishing low thermal conductivity of 0.026 W m-1 K-1 and high reflectivity and emissivity of exceeding 90% over an extremely wide range. The expected dual-effect thermal management performance enables the HS to have an ideal cooling effect under both high sunlight intensity and strong light radiation. In addition, HS also shows excellent flame retardant performance arising from the excellent high-temperature stability of h-BN and SiO2. What is more, the tensile strength of HS0.9 was also significantly increased from 0.42 to 7.2 MPa by encapsulating polyimide through vacuum filtration. Therefore, the research results of this work provide innovative highlights for high-temperature protection in daily life and even extreme space environments.

Continuous Rapid Fabrication of Ceramic Fiber Sponge Aerogels with High Thermomechanical Properties via a Green and Low-Cost Electrospinning Technique

Ceramic aerogel is an appealing fireproof and heat-insulation material, but synchronously improving its mechanical and thermal properties is a challenge. Moreover, the expensive discontinuous processing techniques inhibit the large-scale fabrication of ceramic aerogels. Here, we propose a water-based electrospinning method, based on the hydrolysis and condensation reactions of ceramic precursor salts themselves, for the continuous and rapid (0.025 m3/min) fabrication of ceramic fiber sponge aerogels with dual micronano fiber networks, which show synchronous enhanced fireproof, thermal insulation, and resilience performance. The elastic ceramic micro/nano fiber sponge aerogels contain robust silica-based microfibers as a firm skeleton and alumina-based nanofibers as elastic thermal insulation filler. The sponges have a high porosity of >99.8%, a low mass density (6.21 mg/cm3), a small thermal conductivity (0.022 W/m·K), and a large compression strength (21.15 kPa at 80% strain). The ceramic fiber sponges can effectively prevent the propagation of thermal runaway when a lithium battery experiences catastrophic thermal shock (>1000 °C) in the power battery packs. The proposed strategy is feasible for low-cost and rapid synthesizing ceramic aerogels toward effective battery thermal management.

Functional fibers/textiles for smart sensing devices and applications in personal healthcare systems

Personalized medical diagnostics and monitoring have become increasingly important due to inefficient and delayed medical services of traditional centralized healthcare systems. To enhance the comfort and portability, flexible health monitoring systems have been developed in recent years. In particular, smart fiber/textile-based sensing devices show superiority for continuously monitoring personal health and vital physiological parameters owing to their light weight, good flexibility and inherent miniaturization. This review focuses on the recent advances in smart fiber/textile-based sensing devices for wearable electronic applications. First, fabrication strategies of smart sensing fibers/textiles are introduced in detail. In addition, sensing performances, working principles and applications of smart sensing fibers/textiles such as pressure sensing fibers/textiles, stretchable strain sensing fibers/textiles, temperature sensing fibers/textiles, and biofluid, gas and humidity sensing fibers/textiles in health monitoring are also reviewed systematically. Finally, we propose current challenges and future prospects in the area of fiber/textile-based sensors for wearable healthcare monitoring and diagnosis systems. In general, this review aims to give an overall perspective of the promising field by reviewing various fiber/textile-based sensing devices and highlighting the importance for researchers to keep up with the sequential exploration of soft sensing fibers/textiles for applications in wearable smart systems.

Tailoring Practical Solid Electrolyte Composites Containing Ferroelectric Ceramic Nanofibers and All-Trans Block Copolymers for All-Solid-State Lithium Metal Batteries

Ion transport efficiency, the key to determining the cycling stability and rate capability of all-solid-state lithium metal batteries (ASSLMBs), is constrained by ionic conductivity and Li+-migration ability across the multicomponent phases and interfaces in ASSLMBs. Here, we report a robust strategy for the large-scale fabrication of a practical solid electrolyte composite with high-throughput linear Li+-transport channels by compositing an all-trans block copolymer PVDF-b-PTFE matrix with ferroelectric BaTiO3-TiO2 nanofiber films. The electrolyte shows a sustainable electromechanical-coupled deformability that enables the rapid dissociation of anions with Li+ to create more movable Li+ ions and spontaneously transform the battery internal strain into Li+-ion migration kinetic energy. The ceramic framework homogenizes the interfacial potential with electrodes, endowing the electrolyte with a high conductivity of 0.782 mS·cm-1 and stable ion transport ability in ASSLMBs at room temperature. The batteries of LiFePO4/Li can stably cycle 1000 times at 0.5 C with a high capacity retention of 96.1%, and Ah-grade pouch or high-voltage Li(Ni0.8Mn0.1Co0.1)O2/Li batteries also exhibit excellent rate capability and cycling performance.

Comparison of extraction processes, characterization and intestinal protection activity of Bletilla striata polysaccharides

We optimized the extraction process of Bletilla striata polysaccharides using orthogonal design, Box-Behnken design (BBD), and genetic algorithm-back propagation (GA-BP), then compared and evaluated them to confirm that the combination of BBD and GA-BP neural networks was capable of increasing polysaccharide yields and antioxidant activity. The optimal extraction parameters were as follows: liquid-to-solid ratio of 15 mL/g, extraction power of 450 W, and extraction time of 34 min. Under these conditions, the polysaccharide yield and antioxidant activity were 8.29 ± 0.50 % and 26.20 ± 0.28 (mM FE/mg). Subsequently, the polysaccharide was purified to obtain purified Bletilla striata polysaccharides 1 (pBSP1) with a Mw of 255.172 kDa. Scanning electron microscope (SEM), ultraviolet-visible detector (UV), fourier transform infrared spectrometer (FTIR), high performance liquid chromatography (HPLC), X-ray diffraction (XRD), nuclear magnetic resonance (NMR) and periodate oxidation were used to analyze the structure of pBSP1. The results showed pBSP1 had a smooth surface and a rough interior, with a composition of α-D conformation glucose (18.23 %) and β-D conformation mannose (53.77 %), and an amorphous crystal structure. According to the results of thermogravimetric and rheological tests, pBSP1 exhibits good thermal stability and viscoelastic behavior. Furthermore, pBSP1 protected lipopolysaccharide (LPS)-induced GES - 1 and Caco2 cells, the results showed pBSP1(400 μg/mL) lowered TEER synthesis in Caco2 cells as well as apoptosis and reactive oxygen species (ROS) production in both cells, indicating that pBSP1 may have an intestine protective effect.

Control of metal oxides' electronic conductivity through visual intercalation chemical reactions

Cation intercalation is an effective method to optimize the electronic structures of metal oxides, but tuning intercalation structure and conductivity by manipulating ion movement is difficult. Here, we report a visual topochemical synthesis strategy to control intercalation pathways and structures and realize the rapid synthesis of flexible conductive metal oxide films in one minute at room temperature. Using flexible TiO2 nanofiber films as the prototype, we design three charge-driven models to intercalate preset Li+-ions into the TiO2 lattice slowly (µm/s), rapidly (mm/s), or ultrafast (cm/s). The Li+-intercalation causes real-time color changes of the TiO2 films from white to blue and then black, corresponding to the structures of LixTiO2 and LixTiO2-δ, and the enhanced conductivity from 0 to 1 and 40 S/m. This work realizes large-scale and rapid synthesis of flexible TiO2 nanofiber films with tunable conductivity and is expected to extend the synthesis to other conductive metal oxide films.

Bubble Templated Flexible Ceramic Nanofiber Aerogels with Cascaded Resonant Cavities for High-Temperature Noise Absorption

Aviation noise pollution has become a significant public health problem, especially with the endless improvement of flight speed and loading capacity. Existing aviation noise absorbers have fatal defects of large weight, weak high-temperature stability, and difficulty to achieve both good low-frequency (<1000 Hz) and high-frequency (up to 6000 Hz) noise absorption simultaneously. Herein, we report a robust strategy to create flexible ceramic nanofiber aerogels with cascaded resonant cavities by the air bubbles-assisted freeze-casting technology. The stable hinged resonance cavity structures coassembled by flexible ceramic nanofibers, soft montmorillonite nanosheets, and silica sol glue endow the aerogels with temperature-invariant compressibility (from -196 to 1100 °C) and bendability. Moreover, the comprehensive advantages of cascaded resonance cavities and interconnected fibrous networks enable flexible ceramic nanofiber aerogels to have temperature-invariant full-frequency noise absorption performance (noise reduction coefficient up to 0.66 in 63-6300 Hz). The synthesis of this flexible ceramic nanofiber aerogel provides a versatile platform for the design of high-efficiency noise-absorbing material for various fields.

Fabrication of Flexible Mesoporous Black Nb2 O5 Nanofiber Films for Visible-Light-Driven Photocatalytic CO2 Reduction into CH4

Achieving high selectivity and conversion efficiency simultaneously is a challenge for visible-light-driven photocatalytic CO₂ reduction into CH₄ . Here, a facile nanofiber synthesis method and a new defect control strategy at room-temperature are reported for the fabrication of flexible mesoporous black Nb₂ O₅ nanofiber catalysts that contain abundant oxygen-vacancies and unsaturated Nb dual-sites, which are efficient towards photocatalytic production of CH₄ . The oxygen-vacancy decreases the bandgap width of Nb₂ O₅ from 3.01-2.25 eV, which broadens the light-absorption range from ultraviolet to visible-light, and the dual sites in the mesopores can easily adsorb CO₂ , so that the intermediate product of CO* can be spontaneously changed into *CHO. The formation of a highly stable NbCHO* intermediate at the dual sites is proposed to be the key feature determining selectivity. The preliminary results show that without using sacrificial agents and photosensitizers, the nanofiber catalyst achieves 64.8% selectivity for CH₄ production with a high evolution rate of 19.5 µmol g^-1 h^-1 under visible-light. Furthermore, the flexible catalyst film can be directly used in devices, showing appealing and broadly commercial applications.

High-throughput production of kilogram-scale nanofibers by Kármán vortex solution blow spinning

The interaction between gas flow and liquid flow, governed by fluid dynamic principles, is of substantial importance in both fundamental science and practical applications. For instance, a precisely designed gas shearing on liquid solution may lead to efficacious production of advanced nanomaterials. Here, we devised a needleless Kármán vortex solution blow spinning system that uses a roll-to-roll nylon thread to deliver spinning solution, coupled with vertically blowing airflow to draw high-quality nanofibers with large throughput. A wide variety of nanofibers including polymers, carbon, ceramics, and composites with tunable diameters were fabricated at ultrahigh rates. The system can be further upgraded from single thread to multiple parallel threads and to the meshes, boosting the production of nanofibers to kilogram scale without compromising their quality.

Multifunctional Protection Layers via a Self-Driven Chemical Reaction To Stabilize Lithium Metal Anodes

The Li metal anode is considered one of the most potential anodes due to its highest theoretical specific capacity and the lowest redox potential. However, the scalable preparation of safe Li anodes remains a challenge. In the present study, a LiF-rich protection layer has been developed using self-driven chemical reactions between the Li_3xLa_2/3-xTiO₃/polyvinylidene fluoride/dimethylacetamide (LLTO/PVDF/DMAc) solution and the Li metal. After coating the LLTO/PVDF/DMAc solution to Li foil, PVDF reacted with Li spontaneously to form LiF, and the accompanying Ti⁴⁺ ions (in LLTO) were reduced to Ti³⁺ to form a mixed ionic and electronic conductor Li_xLLTO. The protective layer can redistribute the Li-ion transport, regulate the even Li deposition, and inhibit the Li dendrite growth. When paired with LiFePO₄, NCM811, and S cathodes, the batteries have demonstrated excellent capacity retention and cycling stability. More importantly, a volumetric energy density of 478 Wh L^-1 and 78% capacity retention after 310 cycles have been achieved by using a S/Li_xLLTO-Li pouch cell. This work provides a feasible avenue to provide large-scale preparation of safe Li anodes for the next-generation pouch-type Li-S batteries as ideal power sources for flexible electronic devices.

Superior Flexibility in Oxide Ceramic Crystal Nanofibers

Oxide crystal ceramics are commonly hard and brittle, when they are bent they typically fracture. Such mechanical response limits the use of these materials in emerging fields like wearable electronics. Here, a polymer-induced assembly strategy is reported to construct orderly assembled TiO₂ crystals into continuous nanofibers that are stretchable, bendable, and even knottable. Ball-milling the spinning sol and curved-drafting the electrospun nanofibers significantly improve the molecular structural order and reduce pore defects in the precursor nanofibers. Using this method, continuous TiO₂ nanofibers, in which orderly assembled TiO₂ nanocrystals (brick) are connected by twin grain boundaries or an amorphous region (mortar), are formed after sintering. Mechanical measurements and finite element analysis simulation indicate that the dislocation slip of "bricks" and the elastic deformation of "mortar" render the nanofibers with a small bending rigidity of ≈22 mN and a small elastic modulus of ≈20.8 Gpa, thus displaying properties associated with both soft and hard matter. More importantly, the reported approach can be easily extended to synthesize a wide range of soft, yet tough ceramic membranes, such as ZrO₂ and SiO₂ .

Electronic Textiles Fabricated with Graphene Oxide-Coated Commercial Textiles

Demand for wearable and portable electronic devices has increased, raising interest in electronic textiles (e-textiles). E-textiles have been produced using various materials including carbon nanotubes, graphene, and graphene oxide. Among the materials in this minireview, we introduce e-textiles fabricated with graphene oxide (GO) coating, using commercial textiles. GO-coated cotton, nylon, polyester, and silk are reported. The GO-coated commercial textiles were reduced chemically and thermally. The maximum e-textile conductivity of about 10 S/cm was achieved in GO-coated silk. We also introduce an e-textile made of uncoated silk. The silk-based e-textiles were obtained using a simple heat treatment with axial tension. The conductivity of the e-textiles was over 100 S/cm.

Facile Synthesis of Bimetallic Fluoride Heterojunctions on Defect-Enriched Porous Carbon Nanofibers for Efficient ORR Catalysts

The development of efficient and stable catalysts for the oxygen reduction reaction (ORR) at low cost is crucial for realizing the large-scale application of metal-air batteries. Herein, we report an efficient ORR catalyst of bimetallic copper and cobalt fluoride heterojunctions, which are uniformly dispersed in nitrogen-fluorine-oxygen triply doped porous carbon nanofibers (PCNFs) that contain hierarchical macro-meso-micro pores. The composite catalyst materials are fabricated with a facile and green method of electrospinning with water as the solvent. By using poly(tetrafluoroethylene) as the pore inducer to anchor electropositive copper and cobalt salts in the electrospun hybrid nanofibers, bimetallic fluoride heterojunctions can be directly formed in PCNFs after calcination. The hierachical porous structures provide an effective way to transport matter, while the bimetallic fluorides expose abundant electroactive sites, both of which result in stable ORR activities with a high half-wave potential of 0.84 V. The study proposes a feasible strategy for the fabrication of nonprecious catalysts.

Solid-State Lithium Metal Batteries with Extended Cycling Enabled by Dynamic Adaptive Solid-State Interfaces

Improving the long-term cycling stability of solid-state lithium (Li)-metal batteries (SSBs) is a severe challenge because of the notorious solid-solid interfacial contact loss originating from the repeated expansion and contraction of the Li anodes. Here, it is reported that high-performance SSBs are enabled by constructing brick-and-mortar electrolytes that can dynamically adapt to the interface changes during cycling. An electrolyte film with a high mechanical strain (250%) is fabricated by filling viscoelastic (600% strain) and piezoelectric block-copolymer electrolytes (mortar) into a mixed conductor Li_0.33 La_0.56 TiO_3-x nanofiber film (brick). During Li-plating, the electrolytes can homogenize the interfacial electric field and generate piezoelectricity to promote uniform Li-deposition, while the mortar can adhere to the Li-anode without interfacial disintegration in the reversed Li-stripping. As a result, the electrolytes show excellent compatibility with the electrodes, leading to a long electrochemical cyclability at room temperature. The symmetrical Li//Li cells run stably for 1880 h without forming dendrites, and the LiFePO₄ /Li full batteries deliver high coulombic efficiency (>99.5%) and capacity retention (>85%) over 550 cycles. More practically, the pouch cells exhibit excellent flexibility and safety for potential practical applications.