Hu Jiana, Liang Caiyun, Li Jiadong, Lin Chuanwei, Liang Yongjiu, Dong Dewen
CAS Key Laboratory of High-Performance Synthetic Rubber and its Composite Materials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
University of Science and Technology of China, Hefei 230026, China.
ACS Appl Mater Interfaces. 2022 Jul 19. doi: 10.1021/acsami.2c07741.
Electromagnetic interference (EMI) shielding materials are highly necessary to solve the problem of electromagnetic radiation. Transition-metal carbide/nitride (MXene) materials offer great potential for the construction of high-performance EMI shields because of their high electrical conductivity and versatile surface chemistry. However, MXene generally suffers from poor mechanical and oxidation-resistant properties, which hinders its practical applications. Herein, flexible, strong, and hydrophobic sandwich-structured composite films (H-S-MXene), consisting of a conductive MXene layer and supporting aramid nanofiber layer, were fabricated using step-by-step vacuum-assisted filtration and dip coating. Given the unique sandwich structure, hydrogen bonding interactions, and covalent cross-linking of the MXene sheets, the H-S-MXene composite films demonstrated simultaneously excellent EMI shielding and mechanical properties. The EMI shielding effectiveness of the H-S-MXene composite film with 20 wt % MXene content reached 46.1 dB at thickness of 23.2 ± 0.5 μm, and the tensile strength of the film reached 302.1 MPa, which outperformed other reported EMI shielding materials. The excellent mechanical flexibility and hydrophobicity of the H-S-MXene composite films ensured a stable EMI shielding performance, which could withstand cycled bending, torsion, and exposure to aqueous environments. These impressive features made the H-S-MXene composite films promising candidates for electronic devices and aerospace. This study provides important guidance for the rational design of stable MXene-based composites with advanced properties.
电磁干扰（EMI）屏蔽材料对于解决电磁辐射问题至关重要。过渡金属碳化物/氮化物（MXene）材料因其高导电性和多样的表面化学性质，在构建高性能EMI屏蔽材料方面具有巨大潜力。然而，MXene通常存在机械性能和抗氧化性能较差的问题，这阻碍了其实际应用。在此，通过逐步真空辅助过滤和浸涂法制备了由导电MXene层和支撑芳纶纳米纤维层组成的柔性、高强度且疏水的三明治结构复合薄膜（H-S-MXene）。鉴于独特的三明治结构、氢键相互作用以及MXene片层的共价交联，H-S-MXene复合薄膜同时展现出优异的EMI屏蔽性能和机械性能。MXene含量为20 wt%的H-S-MXene复合薄膜在厚度为23.2±0.5μm时，EMI屏蔽效能达到46.1 dB，薄膜的拉伸强度达到302.1 MPa，优于其他已报道的EMI屏蔽材料。H-S-MXene复合薄膜出色的机械柔韧性和疏水性确保了稳定的EMI屏蔽性能，能够承受循环弯曲、扭转以及暴露于水环境中。这些令人印象深刻的特性使H-S-MXene复合薄膜成为电子设备和航空航天领域的理想候选材料。本研究为合理设计具有先进性能的稳定MXene基复合材料提供了重要指导。
