Expeditious self-healing supermolecules enabling fireproof and ultra-long-life of intelligent bamboo fire alarm systems

Presently, fire alarm systems are prone to dysfunction owing to the lack of expeditious restoration subsequent to damage, thus leading a notable dissipation of resources. Consequently, the attainment of swift self-healing in fire alarm systems is of substantial scientific and practical consequence. Herein, titanium carbide, ammonium polyphosphate, and 2-ureido-4-pyrimidone grafted carboxymethyl chitosan are utilized as temperature-responsive particles, flame retardants, and healing agents respectively. The bamboo-based fire alarm device with rapid optical drive self-healing is constructed by coupling the low-temperature volatilization induced self-assembly method. Such a device simultaneously realizes the excellent flame retardant with the LOI of 69.7 %, residue mass of about 42.72 % and total heat release of 4.26 KJ g⁻¹, rapid self-healing in 178 s and reliable cycle warning performance with a trigger alarm in about 2 s and 40 cycles. The preeminent photothermal property of MXene enables the local temperature of cracks to increase instantly under the irradiation of near-infrared, which significantly shortens the healing time by nearly 75 times. In addition, the bamboo-based fire alarm device still maintains excellent records after being healed. More importantly, the moisture-triggered formation of quadruple hydrogen bonding self-healing mechanism was demonstrate through molecular dynamics simulations. This work provides a design principle for fire alarm devices and will inspire an exciting field of ultra-long-life smart firefighting applications.