Mechanically robust ANF/MXene composite films with tunable electromagnetic interference shielding performance

MXene-based materials have been widely studied recently for effective electromagnetic interference (EMI) shielding due to the prominent intrinsic electrical conductivity. Nevertheless, the poor mechanical performance of pure MXene films limits the practical application in EMI shielding. Thus, we integrate MXene with aramid nanofiber (ANF) to develop a composite film with layered structure through a simple vacuum-assisted filtration method. The resulting ANF/MXene (20/80) composite exhibits a high electrical conductivity of 879.0 S/cm, EMI shielding effectiveness (SE) of 40.6 dB and specific SE (SSE/t, SE divided by the density and thickness) of 50,491 dB∙cm2∙g−1 with an ultrathin thickness of 3.2 μm. Furthermore, the ANF/MXene (60/40) realizes a balance between mechanical properties and EMI shielding performance with the strength of 201.3 MPa and SE of 28.1 dB, which enables the ANF/MXene composite films as promising EMI shielding materials with excellent mechanical robustness.