Enhanced Electromagnetic Shielding and Thermal Management Properties in MXene/Aramid Nanofiber Films Fabricated by Intermittent Filtration.

High-efficiency electromagnetic interference (EMI) shielding and heat dissipation synergy materials with flexible, robust, and environmental stability are urgently demanded in next-generation integration electronic devices. In this work, we report the lamellar MXene/Aramid nanofiber (ANF) composite films, which establish a nacre-like structure for EMI shielding and heat dissipation by using the intermittent filtration strategy. The MXene/ANF composite film filled with 50 wt % MXene demonstrates enhanced mechanical properties with a strength of 230.5 MPa, an elongation at break of 6.2%, and a toughness of 11.8 MJ·m ³ (50 wt % MXene). These remarkable properties are attributed to the hydrogen bonding and highly oriented structure. Furthermore, due to the formation of the MXene conductive network, the MXene/ANF composite film shows an outstanding conductivity of 624.6 S/cm, an EMI shielding effectiveness (EMI SE) of 44.0 dB, and a superior specific SE value (SSE/ t ) of 18847.6 dB·cm ² /g, which is better than the vacuum filtration film. Moreover, the MXene/ANF composite film also shows a great thermal conductivity of 0.43 W/m·K. The multifunctional MXene/ANF composite films with high-performance EMI shielding, heat dissipation, and joule heating show great potential in the field of aerospace, military, microelectronics, microcircuit, and smart wearable electronics.