Superhydrophobic Ti₃C₂T_x MXene/aramid nanofiber films for high-performance electromagnetic interference shielding in thermal environment

Nowadays, novel two-dimensional (2D) material MXene have attracted extensive interest in the electromagnetic interference (EMI) fields because of outstanding metallic conductivity, unique 2D structure. While it remains a great challenge to construct high-performance EMI shielding MXene-based materials with features of stability and durability and strong mechanical properties. And there are few reports on the evolution of EMI shielding performance of MXene at elevated temperature. Herein, hierarchical structure superhydrophobic Ti₃C₂T_x MXene/aramid nanofiber (SHMA) films were fabricated by strategy of layer-by-layer construction and their EMI shielding at elevated temperature were investigated. Benefiting from the hierarchical structure, different layers shoulder their independent desired functions, and then work together to ensure that SHMA has high-efficient EMI shielding performance with mechanical stability, moisture stability and thermal stability. Interestingly, the SHMA films exhibited excellent EMI shielding performance with EMI shielding effectiveness (SE) over 49.7 dB at thickness of 70 μm in temperature ranging from 25 to 300 °C. After heat test, the EMI SE of SHMA increased anomalously from 49.7 to 63.2 dB, and the variation of EMI shielding performance and microstructure of SHMA in thermal environment had been intensively investigated and discussed. Moreover, the EMI SE of SHMA was maintained after 6 months and 5 cycles of heating at 300 °C in air. These results indicate great application potential of SHMA as high-performance EMI shielding material in civil, military high-tech equipment and integrated electronics operating in thermal environment.