1成果简介

　　本文，孙江曼 副教授、潘凯 教授等在《Carbon》期刊发表名为“Three-dimensional electrospinning and catalytic graphitization directly prepared high flexibility, elasticity and graphitization interwoven crimp micro/nano-carbon-fibrous aerogels”的论文，研究提出一种高效制备高度石墨化柔性微/纳米碳纤维气凝胶（MNCFAs）的方法，该方法结合了集成溶胶湿度调控电纺丝技术与铁催化石墨化工艺。
　　通过将聚丙烯腈（PAN）与Fe3+离子配位，实现了无模板、一步到位的3D电纺工艺，可直接生产自支撑的PAN气凝胶前驱体。经预氧化与铁催化碳化处理后，所得MNCFAs展现出卓越性能：密度低至8.0-15.9 mg cm-3；柔韧性优异，经1000次循环仍保持87%应变；导热系数约0.039 W m -1·K⁻¹，以及超过1.42 S cm⁻¹的卓越电导率。
　　关键在于，铁催化剂使材料能在1200°C的中等温度下实现高石墨化，克服了电纺碳气凝胶固有的低导电性缺陷。该材料在-196°C至300°C宽工作温度范围内展现稳定压阻响应，低压下压阻系数达163.5 kPa⁻¹，高压下达83.2 kPa⁻¹，使其成为柔性压阻传感器的理想材料。该合成方法不仅提升了生产效率，更为设计适用于新一代智能机器人及极端环境传感应用的多功能气凝胶开辟了全新可能性。
　　2图文导读 

　　图1. (a) Schematic of the fabrication of MNCFAs. (b) PAN-MNFA image and lightweight, flexible, tailorable display of MNCFAs. (c) The microstructures of MNCFAs at different magnifications. (d) The application prospect of MNCFAs assembled piezoresistive sensor in extreme environment.

　　图2. Under low (60-70%), optimal (70-80%) and high (80-90%) environmental humidity conditions. (a, e, i) Electrospinning schematic diagrams. (b, f, j) Optical images. (c, g, k) SEM images. (d, h, l) Diameter distribution diagrams.

　　图3. (a) FTIR of PAN-MNFA, pre-oxidized PAN-MNFA and MNCFA. (b) Raman, (c) electric conductivity and (d) XRD of MNCFAs with different carbonization temperatures. (e, f) XRD of MNCFAs carbonized at 1200°C and 1400°C. (g) TEM and HRTEM images of a representative MNCFAs sample. (h) EDS elemental mapping of a single fiber of MNCFAs.

　　图4. (a) An optical image of MNCFA bending and SEM images of bending back. (b) Water contact angle of MNCFA. (c) Compression and rebound of MNCFA. (d) Density-compressive stress at 60% strain of aerogels. (e) Compression stress-strain curves of MNCFA at different compression strain. f Density-compressive stress at 60% strain of MNCFAs. (g) Compression stress-strain cycles curves of MNCFA. (h, i) Lateral and top temperature changes of MNCFA on 310°C hot stage. (j) MNCFA insulation images. (k) Thermal conductivity comparison of different carbon materials.

　　图5. (a) Schematic diagram of the assembled piezoresistive sensor based on MNCFA. (b) I-V curves under different pressures, (c) Sensitivity, (d) Response time and recovery time, (e) Piezoresistive sensing behavior under various applied pressures, (f) Current response to forces with different speeds (g) Stability test and enlarged view of the response curve and (h) Coding words by short or long pressing of the MNCFA-based piezoresistive sensor. (i) Twenty-six English letters in the alphabet and the corresponding symbols in the International Morse code. (j) Demonstration showing the conductivity of MNCFA at different ambient temperatures.
　　3小结
　　本研究成功开发了一种结合铁催化石墨化的集成溶胶电纺策略，用于制备高导电性柔性多孔纳米纤维碳酸纤维（MNCFAs）。通过协调聚丙烯腈（PAN）与Fe³⁺离子，采用无模板、湿度调控的电纺工艺直接制备出具有卷曲纤维和分级多孔结构的自支撑型PAN-MNFA前驱体。基于溶解-沉淀机制，原位生成的Fe/Fe₃C纳米颗粒在1200℃催化了大范围石墨化，突破了传统电纺碳气凝胶的高温限制。所得MNCFAs兼具超低密度、高导电性、超弹性及卓越隔热性，适用于制备压阻式传感器，在-196℃至300℃宽温域内展现高灵敏度、快速响应与稳定运行特性。这项工作为设计适用于严苛环境的下一代柔性电子设备和机器人技术的多功能碳气凝胶，开创了一种可扩展的高效方法。
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