An artificial mud brick structural coating endows bamboo with excellent flame retardant, smoke suppression and reliable fire warning performance

Bamboo and other biomass materials have become essential constituents in architecture and interior decoration owing to their outstanding environmental attributes. Nevertheless, their extensive utilization has given rise to substantial fire safety hazards, with toxic smoke frequently posing a greater lethality than heat. In this research, a fire warning coating with a mud brick structure was fabricated on the bamboo surface (AM@Bamboo) by combining positively charged flame retardant ammonium polyphosphate with the negatively charged groups on the MXene surface through a simple water evaporation-induced self-assembly method. The coating's abundant graded pores effectively suppressed the volatilization of smoke at high temperatures. Specifically, the concentrations of toxic NO 2 , NO, CO, and CO 2 gases released during the combustion of AM@Bamboo decreased notably. Among them, the decreases in peak value of CO and CO 2 were 21.2% and 61.1%, respectively. The limiting oxygen index value of AM@Bamboo rose to 36.06%, and the heat release rate was 166.51 kW/m 2 , which is 45.5% lower than that of bamboo. Simultaneously, MXene generated rutile type TiO 2 with semiconductor properties at high temperatures, endowing bamboo with stable cycling warning capabilities. It can trigger an alarm within 5 s in case of a fire and is capable of cycling warnings for 10 cycles. Consequently, AM@Bamboo can be reused multiple times after a fire, greatly reducing its carbon footprint. This achievement provides novel concepts and methods for enhancing the fire safety of bamboo products, and its potential applications can be extended to emerging fields such as intelligent sensing and monitoring.