超轻、高弹性ZrO2/碳纤维增强石墨烯气凝胶，用雷达和红外隐身等

摘要：还原氧化石墨烯（rGO）气凝胶因其独特的物理特性而受到广泛关注，但其较差的机械特性和不足的功能性阻碍了其进一步应用。本文，山东大学于美杰教授、周传健教授、山东建筑大学徐勇副教授《COMPOS PART B-ENG》期刊发表名为“Ultralight, H

1成果简介

还原氧化石墨烯（rGO）气凝胶因其独特的物理特性而受到广泛关注，但其较差的机械特性和不足的功能性阻碍了其进一步应用。本文，山东大学于美杰教授、周传健教授、山东建筑大学徐勇副教授《COMPOS PART B-ENG》期刊发表名为“Ultralight, Highly Elastic ZrO2/Carbon Fiber Reinforced Reduced Graphene Oxide Aerogels with Radar and Infrared Stealth Capabilities”的论文，研究提出了一种纤维增强 rGO 气凝胶的策略，以提高其机械性能并实现多功能应用。我们制造了用氧化锆（ZrO2）颗粒修饰的碳纤维（CFs）来增强rGO气凝胶。

所制备的气凝胶具有优异的轻质特性（8.62 mg cm-3）和高达90%的压缩变形（320kPa），导热系数低至 25.3 mW m-1 K-1。同时，气凝胶还具有出色的电磁波（EMW）吸收性能，3.4 毫米处的最小反射损耗（RLmin）为 -62.99 dB，有效吸收带宽（EAB）为 8.19 GHz。二氧化锆的引入一举三得：它增强了机械性能，破坏了气凝胶框架内的热传导途径，同时优化了阻抗匹配。这种协同效应实现了雷达-红外隐形应用的双频兼容性，为航空航天应用展示了巨大的潜力。

2图文导读

图1. (a) Schematic synthetic process of ZrO2/CF-rGO aerogel; (b) FTIR spectra of P1Z1 and aP1Z1 (after alkaline hydrolysis); (c) Density and axial shrinkage of aerogels with different ZrO2 contents; (d) Photographs of ZrO2/CF-rGO aerogel.

图 2. (a) XRD patterns of different ZrO2 content; (b) Raman spectra, (c) TG curves of CF-rGO, C2Z1-rGO, C1Z1-rGO, and C2Z3-rGO; FE-SEM images of (d) Longitudinal view, (e) Transverse view, (f) Pore structure; (g) In-plane fiber-reinforced nanosheet morphology; (h) Schematic illustration of fiber-reinforced nanosheets; (i) Morphology of fiber-connected nanosheets for C1Z1-rGO.

图3. (a) Digital photos of the compression process for C1Z1-rGO; (b-e) Compressive tests under 30%, 50%, 70%, 80% and 90% strain of CF-rGO, C2Z1-rGO, C1Z1-rGO, and C2Z3-rGO; (f) Comparison of compressive strength at 50% strain of rGO, CF-rGO, C2Z1-rGO, C1Z1-rGO, and C2Z3-rGO; (g) Fatigue tests of C1Z1-rGO with a compression strain of 50% for 200 cycles; (h) Comparison of maximum compressive strain and corresponding compressive strength between this work and other aerogels.

图4. (a) Overall thermal conductivity, (b) Infrared thermal images, (c) Radiative temperature change curves, (d) Porosity of CF-rGO, C2Z1-rGO, C1Z1-rGO, and C2Z3-rGO; (e) Pore size distribution curves of C1Z1-rGO; (f) Without and with flame-resistant C1Z1-rGO protecting a silkworm cocoon from an alcohol fire burning for 60 s; (g) Schematic illustration of the thermal insulation mechanism of ZrO2/CF-rGO aerogels.

图5. (a) RL plots, (b) The values of RLmin and EAB, (c) Normalized impedance matching characteristics of CF-rGO, C2Z1-rGO, C1Z1-rGO, and C2Z3-rGO; (d-f) Three-dimensional RL diagrams, (g-i) Two-dimensional projection mappings of C1Z1-rGO-600, C1Z1-rGO, and C1Z1-rGO-800.

图6. (a) Real part of the complex permittivity, (b) Imaginary part of the complex permittivity, (c) Real and imaginary parts of the complex permeability, (d) Attenuation constant, (e) Dielectric loss tangent, (f) Cole-Cole curves, (g-i) Impedance matching diagrams of C1Z1-rGO-600, C1Z1-rGO, and C1Z1-rGO-800.

图7. (a) Diagrammatic representation of the EMW absorption mechanism for the ZrO2/CF-rGO; (b) Comparison of thermal insulation and MA properties considering RLmin, density, matching thickness, EAB and thermal conductivity compared to the reported composite aerogels.

3小结

总之，通过纤维增强、冷冻铸造、预氧化和碳化处理等综合方法，成功地制造出了超轻的 ZrO2/CF-rGO 气凝胶。低介电系数和低导热系数 ZrO2 的引入极大地影响了复合气凝胶的机械性能和隔热性能。当 ZrO2：当 ZrO2：PAN：GO 的质量比优化为 1:1:1 时，气凝胶表现出 25.3 mW m-1 K-1 的超低导热率，同时具有优异的抗压韧性，在 90% 应变时的抗压强度达到 320 kPa。气凝胶的密度低至 8.62 mg cm-3。此外，这些气凝胶还具有出色的电磁波吸收能力。在不同的碳化温度下，气凝胶的固有缺陷程度和介电损耗效应有很大不同。值得注意的是，在 700 °C 下碳化的 C1Z1-rGO 具有最佳的阻抗匹配和优异的微波衰减性能，在厚度为 3.4 mm 时，RLmin 超过 -62.99 dB，EAB 为 8.19 GHz。这项工作表明，战略性地加入ZrO2能够协同增强隔热性能和MA性能。这种简单有效的改性方法为开发高性能、双功能气凝胶提供了新的思路。

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