以茄子为原料制备磁性碳气凝胶，用于超宽带电磁吸收和热管理

摘要：磁损耗与介电损耗之间的协同耦合机制被公认为实现高效微波衰减复合材料的关键设计策略。本文，成都理工大学何秦川副教授、王益群副教授等在《ACS Sustainable Chem. Eng》期刊发表名为“Sustainable CoFe-Doped Biomas

1成果简介

磁损耗与介电损耗之间的协同耦合机制被公认为实现高效微波衰减复合材料的关键设计策略。本文，成都理工大学何秦川副教授、王益群副教授等在《ACS Sustainable Chem. Eng》期刊发表名为“Sustainable CoFe-Doped Biomass Carbon Aerogels for Ultra-Broadband Electromagnetic Absorption and Thermal Management”的论文，研究以茄子为碳源成功制备了碳基磁性气凝胶，实现了磁性与介电损耗的相互作用，开发出一种低成本且环保的多功能材料。通过调节金属离子浓度比精确调控电磁微波吸收（EMA）特性。

值得注意的是，当Fe³⁺与Co²⁺以1:2摩尔比掺杂时，双金属离子掺杂碳气凝胶展现出卓越的EMA性能：最大吸收带宽达6.32 GHz，最小驻波比值低至−65.8 dB。其卓越性能源于独特的立体碳骨架结构：合金纳米颗粒嵌入孔-片结构并装饰于碳表面，实现阻抗优化匹配与增强的波耗散性能。其兼具极低密度与优异抗压恢复性能，可承受多次压缩循环，显著推动了生物质气凝胶领域的发展。这种集高EMA效率、环保特性、低成本、热管理与抗压能力于一体的多功能气凝胶材料，在各类电子设备及军事应用领域具有广阔前景。

2图文导读

图1. Schematic diagram of the preparation of CoFe/CEB (a). SEM images of CEB (b) and CEB-3 (c, d). TEM (e, f) and HRTEM (g–i) images of CEB-3 (inset (e1) is the SAED analysis). Element distribution mapping of CEB-3 (j–n).

图2. XRD patterns (a). Raman spectra (b). XPS elemental characteristic spectra of CEB-3 (c–c3). SBET and the average pore size of CEB-3 (d). Comparison of SBET between CEB-3 and materials of the same type (e).

图3. 3D and 2D plots of RL curves for CEB-3 (a, b). EMA characteristics of CEB-3 and at different thicknesses (c, d). Correspondence between impedance matching and RL (e, f). Attenuation constant (α) (g). Impedance matching diagrams for δ-function (h, i). Comparison of RLmin and EABmax of CoFe/CEB composites (j). Performance comparison of CEB-3 with reported aerogels and other materials (k).

图4. Complex permittivity and dielectric loss factor (tan δε) (a–c). Complex permeability and magnetic loss factor (tan δμ) (d–f). Eddy current coefficient (g). Electrochemical impedance spectra (h) and charge transfer resistance (i).

图5. Schematic diagram of stealth coating to reduce radar imaging (a). Example RCS model (b). RCS simulation results for CEB-3 (c, d). Average RCS values for the PEC boards and CoFe/CEB (e). RCS values for each sample obtained at different angles (f).

图6. Sample images of CoFe/CEB composite (a, b). Compression springback images and stress–strain cycling curves (c). Paraffin melting time comparison (d–h). Infrared thermography images and temperature change curves (i). Thermal conductivity performance comparison (j).

图7. Schematic diagram of the EMA mechanism of the CoFe/CEB composites.

3小结

本文成功制备了优良的CoFe/CEB复合材料，经冻干处理后保留了茄子独特的孔隙结构，从而促进了电磁波的反射与散射。双金属离子的浓度对CoFe/CEB复合材料的电磁吸波率（EMA）影响显著，当Fe³⁺/Co²⁺=1:2时，CEB-3展现出更优异的EMA性能。当填料含量为20%、厚度为2.07毫米时，实现了宽带宽（EABmax=6.32 GHz）与强吸收（RLmin=-65.8 dB），这归因于茄子形成的碳基体——其富含三维导电网络并提供大量功能基团，同时结合了介电损耗与磁损耗的协同效应。该材料兼具卓越的热管理与压缩性能，其导热系数极低（0.031 W/(m·K)），在生物质碳气凝胶体系中展现出独特优势。综上所述，以茄子为原料制备的CoFe/CEB复合材料具有制备简易、成本低廉、性能优异等特点，同时兼具绝缘性、轻质性和可压缩性，其性能完全可与结构更复杂的其他气凝胶媲美。

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