Ma Zhonglei, Kang Songlei, Ma Jianzhong, Shao Liang, Zhang Yali, Liu Chao, Wei Ajing, Xiang Xiaolian, Wei Linfeng, Gu Junwei
College of Chemistry and Chemical Engineering, Key Laboratory of Auxiliary Chemistry and Technology for Chemical Industry, Ministry of Education, Shaanxi Key Laboratory of Chemical Additives for Industry, Shaanxi University of Science and Technology, Xi'an, 710021, People's Republic of China.
College of Bioresources Chemical and Materials Engineering, Shaanxi University of Science and Technology, Xi'an, Shaanxi 710021, People's Republic of China.
ACS Nano. 2020 Jul 28;14(7):8368-8382. doi: 10.1021/acsnano.0c02401. Epub 2020 Jul 9.
High-performance electromagnetic interference (EMI) shielding materials with ultraflexibility, outstanding mechanical properties, and superior EMI shielding performances are highly desirable for modern integrated electronic and telecommunication systems in areas such as aerospace, military, artificial intelligence, and smart and wearable electronics. Herein, ultraflexible and mechanically strong aramid nanofiber-TiCT MXene/silver nanowire (ANF-MXene/AgNW) nanocomposite papers with double-layered structures are fabricated the facile two-step vacuum-assisted filtration followed by hot-pressing approach. The resultant double-layered nanocomposite papers with a low MXene/AgNW content of 20 wt % exhibit an excellent electrical conductivity of 922.0 S·cm, outstanding mechanical properties with a tensile strength of 235.9 MPa and fracture strain of 24.8%, superior EMI shielding effectiveness (EMI SE) of 48.1 dB, and high EMI SE/t of 10 688.9 dB·cm, benefiting from the highly efficient double-layered structures, high-performance ANF substrate, and extensive hydrogen-bonding interactions. Particularly, the nanocomposite papers show a maximum electrical conductivity of 3725.6 S·cm and EMI SE of ∼80 dB at a MXene/AgNW content of 80 wt % with an absorption-dominant shielding mechanism owing to the massive ohmic losses in the highly conductive MXene/AgNW layer, multiple internal reflections between TiCT MXene nanosheets and polarization relaxation of localized defects, and abundant terminal groups. Compared with the homogeneously blended ones, the double-layered nanocomposite papers possess greater advantages in electrical, mechanical, and EMI shielding performances. Moreover, the multifunctional double-layered nanocomposite papers exhibit excellent thermal management performances such as high Joule heating temperature at low supplied voltages, rapid response time, sufficient heating stability, and reliability. The results indicate that the double-layered nanocomposite papers have excellent potential for high-performance EMI shielding and thermal management applications in aerospace, military, artificial intelligence, and smart and wearable electronics.
具有超柔韧性、出色机械性能和卓越电磁干扰（EMI）屏蔽性能的高性能电磁干扰屏蔽材料，对于航空航天、军事、人工智能以及智能和可穿戴电子等领域的现代集成电子和电信系统来说是非常理想的。在此，通过简便的两步真空辅助过滤法随后进行热压工艺，制备出了具有双层结构的超柔韧且机械强度高的芳纶纳米纤维-TiCT MXene/银纳米线（ANF-MXene/AgNW）纳米复合纸。所得的双层纳米复合纸中MXene/AgNW含量低至20 wt%，却展现出922.0 S·cm的优异电导率、235.9 MPa的拉伸强度和24.8%的断裂应变的出色机械性能、48.1 dB的卓越电磁干扰屏蔽效能（EMI SE）以及10688.9 dB·cm的高EMI SE/t，这得益于高效的双层结构、高性能的ANF基底以及广泛的氢键相互作用。特别地，当MXene/AgNW含量为80 wt%时，纳米复合纸由于高导电的MXene/AgNW层中的大量欧姆损耗、TiCT MXene纳米片之间的多次内部反射以及局部缺陷的极化弛豫和丰富的端基，呈现出吸收主导的屏蔽机制，其最大电导率为3725.6 S·cm，EMI SE约为80 dB。与均匀共混的材料相比，双层纳米复合纸在电学、机械和电磁干扰屏蔽性能方面具有更大优势。此外，多功能双层纳米复合纸还展现出优异的热管理性能，如在低供电电压下具有高焦耳加热温度、快速响应时间、足够的加热稳定性和可靠性。结果表明，双层纳米复合纸在航空航天、军事、人工智能以及智能和可穿戴电子等领域的高性能电磁干扰屏蔽和热管理应用方面具有出色的潜力。
