MXene-based films via scalable fabrication with improved mechanical and antioxidant properties for electromagnetic interference shielding

Recently, multiple challenges are remained for large-scale preparation of MXene-based films towards electromagnetic interference (EMI) shielding due to the limited durability and poor mechanical performance of MXene itself. Herein, a sandwich-structured MXene composite film was achieved via the casting process by utilizing a non-woven fabric (NWF) substrate that significantly promoted the mechanical properties. Subsequently, waterproof thermoplastic polyurethane (TPU) was manipulated onto the surface of the MXene functional layer to formulate a protective skin. The composite films comprised of an ultrathin MXene layer (1.8 μm) with an excellent EMI shielding efficiency (SE) (>20 dB) and an optimal specific SE of 123,333 dB/cm, which was much higher than most of the relevant reported values for EMI shielding films. To top it all, these films possessed excellent folding resistance and were able to withstand folding over 65,000 times under a tensile load of 4.9 N without avulsion. In particular, the presented films showed outstanding durability and sustainability after soaking in water for 8 days compared to the MXene-based films without TPU.