Layer-by-layer assembly enables electrically conductive, hydrophobic and flame-retardant fabric composites for multifunctional sensing and fire warning

Abstract

It is desirable but still challenging to develop mechanically durable and flame-retardant fabrics with multifunctional sensing capabilities. Here, we propose a facile layer-by-layer assembly and coating strategy to prepare electrically conductive fabric composites (CFCs) with a multiple core-shell structure for strain and temperature sensing and fire warning. MXene nanosheets are assembled onto the cotton fiber surface to construct the electrically conductive network and wrapped by the fire retardant and hydrophobic silicon rubber. The interfacial hydrogen bonding and physical adhesion between the functional layers as well as the outmost surface hydrophobicity protect MXene from air and moisture and ensure the electrical stability and durability of CFCs during mechanical deformations. The multiple shells are synergistically transformed to protective barriers during combustion, endowing the composite fabric with excellent flame retardancy. When suffering from a flame attack, CFCs show a very short response time of less than 1s with a continuous fire warning until the self-extinguishment of the flame. Benefiting from the stretchability, photothermal conversion and thermoelectric performance, CFCs can also be used for strain and temperature sensing. This work provides a rational structure design for high performance and multifunctional fire protection and warning.