A flexible and strong mechanical MXene/CNC electromagnetic shielding film with powerful light-to-heat conversion properties

High-performance electromagnetic interference (EMI) films with high EMI shielding efficiency, low thickness, high mechanical strength, and flexibility have promising applications in electromagnetic (EM) protection of electronic products. Here, a versatile and sustainable wearable EM shielding MXene/cellulose nanocrystals (CNC) composite film was developed by a simple vacuum-assisted filtration method. One-dimensional (1D) ultrafine CNC act as interfacial linkage enhancers, forming a dense 'mortar-brick' structure between CNC and MXene nanosheets, which improves the mechanical properties while maintaining the EMI shielding capability of the films. The obtained films show the better tensile strength (83 MPa) than the pure MXene film (12 MPa). More importantly, the MXene/CNC film exhibits excellent EMI shielding, with an EMI SE of nearly 30 dB at a very low thickness of 7 mu m, and 64.5 dB at a thickness of 61 mu m. In addition, the films possess good mechanical stability, which can be rapidly heated up to 76 0C and remain stable for a long time. This study provides a promising strategy for the design of multifunctional flexible EMI shielding materials.