Laser-induced Janus graphene/poly(p-phenylene benzobisoxazole) fabrics with intrinsic flame retardancy as flexible sensors and breathable electrodes for fire-fighting field

Conventional firefighting clothing and fire masks can protect firemen's safety to a certain extent, whereas cannot perceive environmental hazards and monitor their physical status in real time. Herein, we fabricated two kinds of Janus graphene/poly(p-phenylene benzobisoxazole) (PBO) fabrics by laser direct writing approach and evaluated their performance as intelligent firefighting clothes and fire masks. The results showed that the Janus graphene/PBO fabrics were virtually non-combustible and achieved the highest thermal protection time of 18.91 s ever reported in flame, which is due to the intrinsic flame-retardant nature of PBO fibers. The graphene/PBO woven fabrics-based sensor showed good repeatability and stability in human motion monitoring and NO2 gas detection. Furthermore, the piezoelectric fire mask was assembled with graphene/PBO nonwoven fabric as electrode layer and polyvinylidene fluoride (PVDF) electrostatic direct writing film as piezoelectric layer. The filtration efficiency of the fire mask reaches 95% for PM2.5 and 100% for PM3.0, indicating its effective filtration capability for smoke particles in fires. The respiratory resistance of the piezoelectric fire mask (46.8 Pa) was lower than that of commercial masks (49 Pa), showing that it has good wearing comfort. Besides, the piezoelectric fire mask can be sensitive to the speed and intensity of human breathing, which is essential for indirectly reflecting the health of the human body. Consequently, this work provides a facile approach to fabricate next-generation intrinsic flame-retardant smart textiles for smart firefighting.