Deng Zhiming, Tang Pingping, Wu Xinyu, Zhang Hao-Bin, Yu Zhong-Zhen
State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China.
Beijing Key Laboratory of Advanced Functional Polymer Composites, Beijing University of Chemical Technology, Beijing 100029, China.
ACS Appl Mater Interfaces. 2021 May 5;13(17):20539-20547. doi: 10.1021/acsami.1c02059. Epub 2021 Apr 20.
Although hydrophilic and electrically conductive transition-metal carbon/nitride (MXenes) nanosheets hold great promise for electrically conductive and electromagnetic interference (EMI) shielding applications, the weak interaction among MXene nanosheets makes them difficult to form compressible three-dimensional architectures with high conductivity. Herein, inspired by the plant "", an efficient approach is demonstrated to fabricate conductive and lightweight TiCT MXene/acidified carbon nanotube anisotropic aerogels (MCAs) with superelasticity and high thermal insulation. The MXene nanosheets construct the anisotropic and porous skeleton, while the acidified carbon nanotubes reinforce the pore walls of MXene nanosheets, making the MCAs superelastic and compressible. The superelastic MCA with only 5 wt % of the acidified carbon nanotubes is structurally stable during cyclic compressions at both high and ultralow temperatures. Its high conductivity (447.2 S m) and ultralow density (9.1 mg cm) endow its paraffin composite with a high EMI shielding efficiency of ∼51 dB at an ultralow filler content of 0.3 vol %. When the density of MCA increases to 18.2 mg cm, its EMI shielding effectiveness reaches 90 dB. Additionally, the porous and ultralight MCAs exhibit better thermal insulation performances as compared to commercial melamine and polystyrene foams. Therefore, the superelastic, electrically conductive, lightweight, and thermally insulating MCAs would be promising for EMI shielding applications in space equipment and portable wearable devices.
尽管亲水性且导电的过渡金属碳/氮化物（MXenes）纳米片在导电和电磁干扰（EMI）屏蔽应用方面具有巨大潜力，但MXene纳米片之间的弱相互作用使其难以形成具有高导电性的可压缩三维结构。在此，受植物启发，展示了一种有效的方法来制备具有超弹性和高隔热性的导电且轻质的TiCT MXene/酸化碳纳米管各向异性气凝胶（MCAs）。MXene纳米片构建了各向异性且多孔的骨架，而酸化碳纳米管增强了MXene纳米片的孔壁，使MCAs具有超弹性和可压缩性。仅含5 wt%酸化碳纳米管的超弹性MCA在高温和超低温下的循环压缩过程中结构稳定。其高导电性（447.2 S m）和超低密度（9.1 mg cm）使其石蜡复合材料在0.3 vol%的超低填料含量下具有约51 dB的高EMI屏蔽效率。当MCA的密度增加到18.2 mg cm时，其EMI屏蔽效能达到90 dB。此外，与商用三聚氰胺和聚苯乙烯泡沫相比，多孔且超轻的MCAs表现出更好的隔热性能。因此，这种超弹性、导电、轻质且隔热的MCAs在空间设备和便携式可穿戴设备的EMI屏蔽应用中具有广阔前景。
