Ultralight and Mechanically Robust Fibrous Sponges Tailored by Semi-Interpenetrating Polymer Networks for Warmth Retention

Resilient ultrafine fiber sponges with thermal bridge structures for high-temperature traffic noise reduction

With the expansion of the transportation business, noise pollution has seriously affected human health and quality of life. Vehicles not only generate noise but also release a large amount of heat, existing traffic noise reduction materials have no thermal conductivity and poor low-frequency noise reduction. Herein, thermal bridge structured elastic ultrafine fiber sponges (TBFSs) were constructed in one step through simultaneous high-humidity assisted electrospinning and electrospraying. The thermal bridge structures endow fiber sponges with good thermal conductivity (close to 0.1 W m-1 K-1), increased by 350 % compared with common fiber sponges. More importantly, due to the complex pore channel and the vibration effect of the thermal bridge structures, the TBFSs achieve a high noise reduction coefficient of 0.58, which can reduce the high-temperature white noise by 16.5 dB at 100 °C. Besides, the synergistic effect of elastic polyurethane and heat crosslinking endows TBFSs with good mechanical properties, demonstrating negligible plastic deformation following 100 cycles of compressive loading. The successful development of thermal bridge structures fiber sponges provides a new solution for high-temperature safety noise reduction.

Lightweight and Mechanically Robust Ambient-Electrospun Nanofibrous Sponges Combined with Solar-Driven Active Heating and Low-Temperature Superinsulation

Traditional fibrous warmth retention materials suffer from limited performance improvement due to their micrometer-scale diameter and fail to meet the requirements of lightweight yet high-efficiency cold protection in extreme environments. Herein, we present a novel, facile, and ecofriendly strategy to fabricate a lightweight, mechanically robust nanofibrous sponge with integrated solar-driven active heating and low-temperature superinsulation. The high-porosity structure is achieved through urea-induced phase separation during ambient electrospinning, which overcomes the energy-intensive and unsafe high-humidity processing challenges. Simultaneous in situ incorporation of silicon carbide nanoparticles with photothermal properties enables solar-activated heat generation. This nanofibrous sponge realizes dual functionalities: ultralow thermal conductivity (27.31 mW m-1 K-1) for low-temperature superinsulation and rapid solar heating (50.1 °C temperature rise within 10 min under simulated sunlight), combined with exceptional attributes including lightweight property (volume density of 3.8 mg cm-3), hydrophobicity (water contact angle = 128°), antifouling behavior, and stable mechanical performance. Its superior performance in extreme environments (e.g., high-altitude and polar regions) and medical applications establishes a new paradigm for advanced warmth retention materials with integrated passive/active thermal management functionalities.

Ultralight and Flame-Retardant Nanofiber/Aerogel Microfiber Sponges with Dual-Network Structures for Warmth Retention

Long-term exposure to cold conditions can cause damage to the body, which makes cold prevention equipment urgently needed. However, the most commonly used fibrous warmth retention materials have drawbacks of heavy weight, poor mechanical properties, flammability, and inefficient thermal insulating performance. Herein, we propose a simple and feasible strategy to prepare nanofiber/aerogel microfiber sponges (NAMS) with dual-network structures for warmth retention by direct electrospinning. The aerogel fibers are prepared by regulating the phase separation behavior of the jet, while flexible nanofibers are introduced between the aerogel fibers to construct dual-network structures in the sponge. The obtained NAMS is lightweight (3.44 mg cm-3) and exhibits robust mechanical properties (almost no plastic deformation after enduring 500 stretching cycles and 1000 compression cycles), and efficient warmth retention properties (thermal conductivity of 23.92 mW m-1 K-1). Furthermore, the introduction of a flame retardant enables the NAMS to possess remarkable flame resistance, with a limiting oxygen index of 28.7%. The development of NAMS offers a promising avenue for future advancements in ultralight, flame-retardant, and high-efficiency warmth retention materials.

Recent Advances in Next-Generation Textiles

Textiles have played a pivotal role in human development, evolving from basic fibers into sophisticated, multifunctional materials. Advances in material science, nanotechnology, and electronics have propelled next-generation textiles beyond traditional functionalities, unlocking innovative possibilities for diverse applications. Thermal management textiles incorporate ultralight, ultrathin insulating layers and adaptive cooling technologies, optimizing temperature regulation in dynamic and extreme environments. Moisture management textiles utilize advanced structures for unidirectional transport and breathable membranes, ensuring exceptional comfort in activewear and outdoor gear. Protective textiles exhibit enhanced features, including antimicrobial, antiviral, anti-toxic gas, heat-resistant, and radiation-shielding capabilities, providing high-performance solutions for healthcare, defense, and hazardous industries. Interactive textiles integrate sensors for monitoring physical, chemical, and electrophysiological parameters, enabling real-time data collection and responses to various environmental and user-generated stimuli. Energy textiles leverage triboelectric, piezoelectric, and hygroelectric effects to improve energy harvesting and storage in wearable devices. Luminous display textiles, including electroluminescent and fiber optic systems, enable dynamic visual applications in fashion and communication. These advancements position next-generation textiles at the forefront of materials science, significantly expanding their potential across a wide range of applications.

Pulmonary decellularized extracellular matrix (dECM) modified polyethylene terephthalate three-dimensional cell carriers regulate the proliferation and paracrine activity of mesenchymal stem cells

Introduction: Mesenchymal stem cells (MSCs) possess a high degree of self-renewal capacity and in vitro multi-lineage differentiation potential. Decellularized materials have garnered considerable attention due to their elevated biocompatibility, reduced immunogenicity, excellent biodegradability, and the ability to partially mimic the in vivo microenvironment conducive to cell growth. To address the issue of mesenchymal stem cells losing their stem cell characteristics during two-dimensional (2D) cultivation, this study established three-dimensional cell carriers modified with lung decellularized extracellular matrix and assessed its impact on the life activities of mesenchymal stem cells. Methods: This study employed PET as a substrate material, grafting with polydopamine (PDA), and constructing a decellularized extracellular matrix (dECM) coating on its surface, thus creating the PET/PDA/dECM three-dimensional (3D) composite carrier. Subsequently, material characterization of the cellular carriers was conducted, followed by co-culturing with human umbilical cord mesenchymal stem cells in vitro, aiming to investigate the material's impact on the proliferation and paracrine activity of mesenchymal stem cells. Results and Discussion: Material characterization demonstrated successful grafting of PDA and dECM materials, and it had complete hydrophilicity, high porosity, and excellent mechanical properties. The material was rich in various ECM proteins (collagen I, collagen IV , laminin, fibronectin, elastin), indicating good biocompatibility. In long-term in vitro cultivation (14 days) experiments, the PET/PDA/dECM three-dimensional composite carrier significantly enhanced adhesion and proliferation of human umbilical cord-derived mesenchymal stem cells (HUCMSCs), with a proliferation rate 1.9 times higher than that of cells cultured on tissue culture polystyrene (TCPS) at day 14. Furthermore, it effectively maintained the stem cell characteristics, expressing specific antigens for HUCMSCs. Through qPCR, Western blot, and ELISA experiments, the composite carrier markedly promoted the expression and secretion of key cell factors in HUCMSCs. These results demonstrate that the PET/PDA/dECM composite carrier holds great potential for scaling up MSCs' long-term in vitro cultivation and the production of paracrine factors.

Recycling Coal Fly Ash for Super-Thermal-Insulating Aerogel Fiber Preparation with Simultaneous Al2O3 Extraction

A large quantity of coal fly ash is generated worldwide from thermal power plants, causing a serious environmental threat owing to disposal and storage problems. In this work, for the first time, coal fly ash is converted into advanced and novel aerogel fibers and high-purity α-Al2O3. Silica-bacterial cellulose composite aerogel fibers (CAFs) were synthesized using an in situ sol-gel process under ambient pressure drying. Due to the unique "nanoscale interpenetrating network" (IPN) structure, the CAFs showed wonderful mechanical properties with an optimum tensile strength of 5.0 MPa at an ultimate elongation of 5.8%. Furthermore, CAFs with a high porosity (91.8%) and high specific surface area (588.75 m2/g) can inherit advanced features, including excellent thermal insulation, stability over a wide temperature range, and hydrophobicity (contact angle of approximately 144°). Additionally, Al2O3 was simultaneously extracted from the coal fly ash to ensure that the coal fly ash was fully exploited. Overall, low-cost woven CAFs fabrics are suitable for wearable applications and offer a great approach to comprehensively use coal fly ash to address environmental threats.

Structural Control of Nanofibers According to Electrospinning Process Conditions and Their Applications

Nanofibers have gained much attention because of the large surface area they can provide. Thus, many fabrication methods that produce nanofiber materials have been proposed. Electrospinning is a spinning technique that can use an electric field to continuously and uniformly generate polymer and composite nanofibers. The structure of the electrospinning system can be modified, thus making changes to the structure, and also the alignment of nanofibers. Moreover, the nanofibers can also be treated, modifying the nanofiber structure. This paper thoroughly reviews the efforts to change the configuration of the electrospinning system and the effects of these configurations on the nanofibers. Excellent works in different fields of application that use electrospun nanofibers are also introduced. The studied materials functioned effectively in their application, thereby proving the potential for the future development of electrospinning nanofiber materials.

Direct Synthesis of Elastic and Stretchable Hierarchical Structured Fiber and Graphene-Based Sponges for Noise Reduction

Noise pollution, as one of the three major pollutants in the world, has become a great burden on people's health and the global economy. Most present noise absorbers suffer large weight and inevitable compromise between good low-frequency (usually <1000 Hz) and high-frequency (typically >1000 Hz) noise reduction performance. This study presents a scalable strategy to directly synthesize ultrafine fiber sponges with ultrathin graphene-based vibrators by the synchronous occurrence of humidity-assisted electrospinning and electrospraying. The unique physical entanglements between reduced graphene oxide (rGO) nanosheets and ultrafine fibers endow hierarchical vibration structured fiber sponges (VSFSs) with excellent mechanical properties, which could withstand large shear strain (60%) and tensile stress (6000 times its weight) without damage and almost have no plastic deformation after 1000 compressions. Attribute to the vibration effect of ultrathin graphene-based vibrators and the viscous friction effect of porous fiber networks, the VSFSs achieve both good low-frequency (absorption coefficient of 0.98 in 680 Hz) and high-frequency sound absorption (absorption coefficients above 0.8 in 2000-6300 Hz) simultaneously. Furthermore, the noise reduction coefficient (NRC) of lightweight VSFSs (thickness of 30 mm) reaches 0.63, which could reduce high decibel noise by 24.4 dB, providing potential solutions for developing ideal noise-absorbing materials.

Recent Progress in Protective Membranes Fabricated via Electrospinning: Advanced Materials, Biomimetic Structures, and Functional Applications

Electrospinning is a significant micro/nanofiber processing technology and has been rapidly developing in the past 2 decades. It has several applications, including advanced sensing, intelligent manufacturing, and high-efficiency catalysis. Here, multifunctional protective membranes fabricated via electrospinning in terms of novel material design, construction of novel structures, and various protection requirements in different environments are reviewed. To achieve excellent comprehensive properties, such as, high water vapor transmission, high hydrostatic pressure, optimal mechanical property, and air permeability, combinations of novel materials containing nondegradable/degradable materials and functional structures inspired by nature have been investigated for decades. Currently, research is mainly focused on conventional protective membranes with multifunctional properties, such as, anti-UV, antibacterial, and electromagnetic-shielding functions. However, important aspects, such as, the properties of electrospun monofilaments, development of "green electrospinning solutions" with high solid content, and approaches for enhancing adhesion between hydrophilic and hydrophobic layers are not considered. Based on this systematic review, the development of electrospinning for protective membranes is discussed, the existing gaps in research are discussed, and solutions for the development of technology are proposed. This review will assist in promoting the diversified development of protective membranes and is of great significance for fabricating advanced materials for intelligent protection.

Ultralight, Superelastic, and Washable Nanofibrous Sponges with Rigid-Flexible Coupling Architecture Enable Reusable Warmth Retention

Nanofibrous sponges enable promising potentials in warmth retention but are impeded by short service life and nonwashability, owing to their inadequate mechanical properties. Herein, a scalable strategy is reported to develop ultralight, superelastic, and washable micro/nanofibrous sponges (MNFSs) with a rigid-flexible coupling architecture created by bridging high-modulus polyethylene terephthalate microfibers with flexible polyacrylonitrile nanofibers via robust bonding structures. Meanwhile, the in situ doping of fluoropolymer endows micro/nanofibers with desirable amphiphobicity. The resultant MNFSs present high resilience, superior compressive fatigue resistance (5.7% residual strain at 1000th), low-temperature-resistant superelasticity (up to -196 °C), and unique washing-invariant superelasticity. Moreover, the fascinating structures of high porosity, high tortuosity, and small pores enable MNFSs both ultralight property (7.5 mg cm^-3) and effective warmth retention (28.51 mW m^-1 K^-1). Additionally, the MNFSs possess remarkable antifouling, robust stability, and long service life. The work might provide an avenue to develop mechanically robust nanofibrous sponges for various applications.

Superelastic and Fire-Retardant Nano-/Microfibrous Sponges for High-Efficiency Warmth Retention

Warmth retention equipment for personal cold protection is highly demanded in freezing weather; however, most present warmth retention materials suffer from high thermal conductivity, weak mechanical properties, and strong flammability, resulting in serious security risks. Herein, we report a facile strategy to fabricate nano-/microfibrous sponges with superelasticity, robust flame retardation, and effective warmth retention performance via direct electrospinning. The three-dimensional fluffy sponges with low volume density and high porosity are constructed by accurately regulating the relative humidity; meanwhile, the mechanically robust polyamide-imide nanofibers with high limit oxygen index (LOI) are innovatively introduced to improve the structural stability and flammability of the nano-/microfibrous sponges. Strikingly, the developed nano-/microfibrous sponges exhibit ultralight characteristics (6.9 mg cm^-3), superelasticity (∼0% plastic deformation after 100 compression tests), effective flame retardant with LOI of 26.2%, and good heat preservation ability (thermal conductivity of 24.6 mW m^-1 K^-1). This work may shed light on designing superelastic and flame-retardant warmth retention materials for various applications.