超稳定石墨烯气凝胶的电磁屏蔽性能研究

Ultra-stable graphene aerogels for electromagnetic interference shielding

石墨烯气凝胶(GAs)在解决下一代电子器件电磁屏蔽污染方面引起了广泛关注.但是,由于超轻石墨烯气凝胶在复杂环境中结构不稳定,其在电磁屏蔽的实际应用中仍面临巨大的挑战.在此,我们提出一类机械结构稳定的石墨烯气凝胶,其展示出优异可靠的电磁屏蔽性能.这类气凝胶呈现出面面堆叠的结构,在密度ρ=3.7 mg cm-3,高度1 m m时,电磁屏蔽效能可达到64.1 d B,比电磁屏蔽效能达到173,243 dB cm2g-1,远超现有报道的碳基材料.同时,石墨烯气凝胶具有优异的环境适应性,在机械形变、极端温度、燃烧及水下等环境中均可保持性能稳定.此外,制备的石墨烯气凝胶可通过真空袋装工艺进行包装运输,解决了超轻材料实际应用中低密度与大体积的矛盾,且在这一极端变形过程中材料结构和性能均未产生破坏.该研究为石墨烯气凝胶电磁屏蔽材料的实际应用铺平了道路,且拓展了其实际应用场景,比如航天、军事战机及海洋领域.

Graphene aerogels(GAs) are prevailing to solve electromagnetic interference(EMI) issues in next-generation electronic devices. However, the practical EMI shielding application of lightweight GAs is still a great challenge because of their structural instability when confronted with complex conditions. Here, we report a class of ultra-stable GAs with excellent and reliable EMI shielding performances. The GA(ρ = 3.7 mg cm-3) with face-to-face stacked structure exhibits a high shielding effectiveness(SE) of 64.1 dB at the thickness of1 mm. The specific EMI SE reaches 173,243 dB cm~2g-1, far beyond the previous carbon-based materials. Meanwhile, the structural stability endows the GAs with outstanding resistance to external stimuli, such as mechanical deformation,extreme temperature, flame and underwater environments.The intrinsic conflict of low density and oversized volume is solved by vacuum bagging without structure and performance loss. Our GAs have paved the way for the practical EMI shielding materials and greatly broadened the applied scenes,such as aerospace, warcraft and ocean fields.