Microwave-induced segregated composite network with MXene as interfacial solder for ultra-efficient electromagnetic interference shielding and anti-dripping

MXenes, a fast-growing family of two-dimensional (2D) materials, can offer an excellent electromagnetic interference (EMI) shielding performance because of ultra-high electrical conductivity, multi-layered structure, and abundant termination groups. In turn, as a result of the favorable interaction with electromagnetic wave, MXene might evoke an intense energy conversion from electromagnetic energy to thermal energy upon exposure to the microwave irradiation. Herein, for the first time, the microwave heating behavior of Ti3C2Tx caused by the strong electromagnetic wave absorption was investigated. Ti3C2Tx nanosheets were flocculation-assembled onto the surface of polypropylene (PP) and used as the "interfacial solder", inducing a unique selective heating to construct a continuous and compact network in segregated Ti3C2Tx/PP composite under the optimal microwave field. The sintered composite possessed the ultrahigh EMI shielding effectiveness (EMI SE) of 75.12 ~ 78.85 dB over the X-band with an extremely low Ti3C2Tx loading of 1.138 vol%, superior to the vast majority of Ti3C2Tx-based polymer composites. In addition, the compact Ti3C2Tx frameworks also provided an excellent anti-dripping performance for composite even with 0.284 vol% Ti3C2Tx. Therefore, by fully utilizing the intrinsic response of MXene to electromagnetic wave, we developed a novel method for not only process molding but also structural/chemical decoration of MXene-based materials.