Flame-Retardant MXene/Aramid Nanofiber/PEG Composite Film for Wearable Fire Cyclic Warning and Protection

Thermal sensing materials capable of monitoring critical fire risks of combustible materials with a rapid response show great potential in early fire warning. However, the thermoelectric materials used in current fire-warning systems usually have low mechanical strength and poor flexibility, limiting their application in harsh environments and in wearable devices. In this work, a class of multilaminated MXene/aramid nanofiber (ANF)/poly(ethylene glycol) (PEG) composite film (MAP) was developed by a vacuum-induced self-assembly method. Because of the compatibility of the hybrid building units with reinforced interconnections, the MAP films exhibit excellent mechanical properties in terms of tensile strength (139.9 MPa), toughness (20.7 MJ/m 3 ), strain (23.1%), modulus (6.1 GPa), and durability (fold times: 39,991). Moreover, the MAP films showed superior fire retardancy with the LOI value of 35%, exhibiting rapid self-extinguishing capability. Significantly, taking advantage of the thermoelectric effect and continuous conductive paths of MXene nanosheets, rapid cyclic contact/noncontact fire warning (<1 s) was achieved. Integrating the MAP film into the IoT system enabled remote real-time fire monitoring and feedback with a rapid response. In addition, the MAP film can be employed as an early fire-warning coating on textiles, further expanding its wearable fire alarm scope. This work provides a perspective for designing robust wearable early fire detection sensors and fire protection applications.