Flexible and Recyclable MXene Nanosheet/Ag Nanowire/Cellulose Nanocrystal Composite Films for Electromagnetic Interference Shielding

With the increasing popularity of electronic communication equipment, electromagnetic pollution continues to worsen, and the requirement for ultrathin, highly flexible, and multifunctional electromagnetic interference (EMI) shielding films is becoming more imperative. Within this study, composite films were prepared by introducing one-dimensional (1D) cellulose nanocrystals (CNC) and silver nanowires (AgNWs) into two-dimensional (2D) MXene-based materials using the method of vacuum-filtration-induced self-assembly. Benefiting from the 1D/2D conductive network composed of AgNWs and MXene, the composite film has a high conductivity (36,244 S m–1) and excellent EMI shielding performance (69.94 dB) at a thickness of 54 μm. The introduction of a 1D sustainable CNC as a "binder" increased the tensile strength of the composite film from 16.75 MPa (pure Ti3C2Tx MXene film) to 26.14 MPa. In addition, the MXene/AgNWs/CNC composite films have outstanding Joule heating performance, and the surface temperature exceeded 70.2 °C under 2.5 V. Moreover, the MXene/AgNWs/CNC composite films have recyclable properties, and the test results indicate that the EMI SE value of the composite films is 40.78 dB after recycling. We believe that the designed MXene/AgNWs/CNC composite films have promising applications with respect to electromagnetic protection in flexible wearable devices, aerospace systems, and extreme environments.