From\nMXene Trash to Ultraflexible Composites for Multifunctional\nElectromagnetic Interference Shielding

Abstract

The development of flexible composites\nbased on the transition\nmetal carbides/nitrides (MXenes) is gaining popularity because of\nMXenes’ high application potentials for electromagnetic interference\n(EMI) shields. Here, we prepare a new type of ultraflexible composite\nfilms composed of “trashed” MXene sediment (MS) and\nwaterborne polyurethane using a simple, facile solution casting approach.\nIn addition to the outstanding mechanical strength and electrical\nconductivity, an extremely wide-range of MS contents can be achieved\nfor the composites, resulting in EMI shielding effectiveness (SE)\nthat may be controlled over a wide range. The X-band EMI SE of the\nflexible, low-density composites containing 70 wt % MS reaches 45.3\ndB at a thickness of merely 0.51 mm. Moreover, the SE values of more\nthan 34.5 dB in the ultrabroadband gigahertz frequency range including\nX-band, P-band, K-band, and R-band, are accomplished for the thin\ncomposites. Furthermore, the MS/WPU composite films show excellent\nelectrothermal and photothermal performance, demonstrating the multifunctionalities\nof the MS-based EMI shields. Combined with the cost-efficient, sustainable,\nand scalable preparation approach, the ultraflexible, multifunctional\ncomposites from “trashed MXene” show great potentials\nfor next-generation electronics. This work also opens a new avenue\nfor the creation of innovative, high-performance, multifunctional\nflexible composites.