1成果简介

 

         高性能气凝胶材料在极端寒冷环境中维持人体热舒适性方面备受期待。然而，开发兼具轻质、机械强韧且能为人体保暖的此类材料仍面临巨大挑战。本文，东华大学丁彬 教授团队在《Mater Today》期刊发表名为“Stiff-Soft synergistic aerogel fibers/nanonets triggered stretchable fiber/graphene oxide meta-aerogel for high-performance personal heating”的论文，研究提出通过三维（3D）电纺/网状自组装策略，直接合成了具有拓扑气凝胶纤维/纳米网结构的可拉伸超材料气凝胶。
        通过操控从泰勒锥喷射出的带电液体变形与相变，形成了由刚性气凝胶纤维与柔性自组装纳米网构成的拓扑纠缠双网络。所得超材料气凝胶展现出卓越的结构稳定性：具备超大伸展性（超过自身重量的2000倍）、经受1000次30%拉伸应变循环与1000次60%压缩应变循环的高韧性，以及在-196℃的低温弹性恢复能力。依托气凝胶纤维、纳米网及纤维间孔隙构成的分级孔隙结构，该超材料气凝胶兼具轻量化密度（4.8 mg cm?³）与可靠的低热导率（24.3 mW m?¹ K?¹）。此外，该超材料气凝胶集成了可重复的被动与主动加热功能，能使人体皮肤升温4.1℃，使其成为全天候室内外个人供暖的理想候选材料。这项研究有望为纤维状气凝胶在各类应用领域的发展提供重要推动力。
        2图文导读 

 

        图1. Assembly strategy and architecture of FGA. a Schematic illustration of 3D electro-spinning/netting self-assembly for directly synthesizing stretchable FGA. b-d Microstructural images of FGA at different magnifications. e Diameter distribution of aerogel fibers and nanonets. f Optical photograph showing FGA standing atop a fresh flower. g FGA can be stretched (left) and compressed (right) without being destroyed. h Schematic of the working principle of FGA for all-day personal heating (left). The right shows skin temperature rise at different heating modes.

 

 

        图2. Fabrication and characterization of FGA. a Schematic illustration of the formation process of PSU aerogel fiber based on humidity-induced jet gelation. b Ternary phase diagram of the PSU/DMF/H2O system. cSEM image of PSU aerogel fiber with a rough surface. SEM images of PSU fiber assemblies prepared at RH ofd30% ande90%. Inset showing the corresponding optical thickness. SEM images offFGA0 andgFGA10.hSurface and cross-section SEM images of FGA.iPore size distribution,j BET surface area, and pore volume for FGA0 and FGA10.

 

 

        图3. Mechanical properties of FGA. a Tensile σ-ε curves. b Cyclic σ-ε curves at a tensile ε of 30%. c FE simulation results of the microstructure evolution of FGA under stretch. d Compress σ-ε curves. e Cyclic σ-ε curves at a compress ε of 60%. f Schematic diagram of compressive elasticity. SEM image showing the co-deformation behavior of aerogel fibers and nanonets. g Comparison of recoverable compressibility, recoverable stretchability, and volume density of FGA with other cutting-edge aerogels. h Maximum stress, Young’s modulus, and energy loss coefficient versus compressive cycles. i Storage modulus, damping ratio, and loss modulus versus compression frequency. j Compressive elasticity demonstration of FGA in liquid nitrogen.   

 

        图4. Multimode personal heating performance of FGA. a Thermal conductivity versus volume density for different thermal insulation materials. b IR images of FGA on the hot stage during the 10-minute heating process. c IR emissivity of FGA and cotton. d Temperature comparison between simulated skin covered with FGA and cotton. e Solar absorptivity of FGA and cotton. f Temperature comparison of FGA and cotton under one sun irradiance. Inset showing IR image of FGA-covered palm. g Real-time temperature of FGA and cotton at different sun irradiances. h Real-time temperature of FGA at various applied voltages. Real-time temperature of human skin covered with FGA and cotton at different heating modes of i thermal insulation & radiative heating, j thermal insulation & radiative heating & solar heating, and k thermal insulation & radiative heating & Joule heating, respectively.
        3小结
        综上所述，通过简便高效的3D电纺/网状自组装技术，成功开发出兼具高机械韧性与多模式加热调控功能的轻质FGA材料。通过调控从泰勒锥喷射出的带电液体的变形和相变，创新性地构建了由气凝胶纤维（约2微米）和纳米网（约140纳米）组成的刚柔协同拓扑缠结双网络。这种理想结构赋予FGA卓越的机械性能：可承受超过自身重量2000倍的高拉伸应力，经受60%应变下1000次压缩疲劳循环，并在-196℃低温环境中保持弹性恢复能力。此外，分级多孔结构（孔隙率99.6%）使FGA具备轻量化密度（4.8 mg cm?³）与低热导率（24.3 mW m?¹ K?¹）。值得注意的是，FGA凭借高效的多模式加热能力（包括隔热、辐射、太阳能及焦耳加热），可作为全天候室内外个人加热器使用，能使人体皮肤温度升高4.1℃。这项研究有望为开发新一代先进热管理材料铺平道路，并显著推动噪声吸收、组织工程及空气过滤等领域的尖端研究与应用。
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