Ultrastrong and Hydrophobic Sandwich-Structured MXene-Based Composite Films for High-Efficiency Electromagnetic Interference Shielding

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 HAI SE (ES) 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 mu m, 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.

Automated summary

Transition-metal carbide/nitride (MXene) materials with high electrical conductivity and versatile surface chemistry offer great potential for high-performance EMI shields. In this study, a sandwich-structured composite film (H-S-MXene) was fabricated, consisting of a conductive MXene layer and supporting aramid nanofiber layer. The H-S-MXene composite film demonstrated excellent EMI shielding and mechanical properties. It also exhibited impressive mechanical flexibility and hydrophobicity, ensuring stable EMI shielding performance in various environments. The H-S-MXene composite films are promising candidates for electronic devices and aerospace.