Flame-retardant AlOOH/graphene oxide composite coating with temperature-responsive resistance for efficient early-warning fire sensors

The eco-friendly and simple layer-by-layer (LbL) self-assembly process is used to create a graphene oxide (GO) and aluminum oxide hydroxide (AlOOH) functional coating on melamine foam (MF) by utilizing the hydrogen bonding interaction. The manufactured composite foam exhibits good hydrophobicity and structural stability in the both strong acidic and alkaline solutions. The AlOOH-GO composite coating's electrical resistance is susceptible to flame and high temperature, allowing for ultra-fast fire detection and efficient fire-warning response. When the composite foam is attacked by flame, it triggers an alarm signal within 2.5 s and a continuous alarm time access of 256 s, demonstrating exceptional early fire-warning capability. The thermal stability of this combustible foam is improved by the optimized AlOOH-GO composite coating. The AlOOH-GO composite coating endows MF with exceptional flame-retardant properties, including self-extinguishing and structural integrity after combustion. This work proposes an efficient method for considerably reducing the fire hazard of flammable materials and expanding the applications in a fire early detection and warning. • A novel early fire-alarm sensor was designed based on AlOOH-GO nano-coating. • The sensitivity and stability of this novel fire sensor were excellent. • The fire-alarm and flame-retardant mechanisms of AlOOH-GO nano-coating were studied.