Mechanically durable MXene based nanofiber composite membranes with asymmetric superhydrophilicity/hydrophobicity for unidirectional water transport and temperature sensing

Wearable fibric materials have shown wide applications in flexible electronics, and it is desired that smart fibric/fiber materials possess excellent breathability, durability and sweat-wicking capabilities. Here, we develop an electrically conductive Janus nanofiber composite (CJNCs) with outstanding unidirectional water transportation (UWT) ability by regulating MXene nanosheet distribution. MXene/chitason are assembled on the polyurethane (PU) surface to obtain a superhydrophilic layer with a large thickness, while MXene nanosheets embedded PU nanofibres with a smaller thickness is deposited onto the superhydrophilic layer to construct a Janus structure with asymmetric wettability. The Janus structure demonstrates outstanding interfacial stability, guaranteeing the excellent durability of the UWT behavior. The UWT time can be diminished to around 10 s, and the anti-gravity water transportation time is only 18 s. In addition, CJNCs displays superior photo-thermal effect and temperature sensing behavior. This work presents an effective and facile strategy toward fabricating multifunctional fibrous materials with potential applications in smart and wearable sensing electronics.