Intelligent fire warning system is a crucial protective equipment reduce fire hazards . A recent increasing concern is the development of sensitive fire warning materials that can be integrated with combustible materials to provide real-time alarms in the fire. However, current research on improving the sensitivity of fire warning sensors based on temperature-resistance response focuses on constructing continuous conductive networks. The effect of the heat transfer process is ignored, which limits the further improvement of alarm sensitivity. Here, we developed a strategy to improve thermal conductivity . Based on the chitosan (CS) conductive network in Ti 3 O 5 -based fire sensing system, aminated 2D h-BN nanosheets with high temperature resistance and ultrahigh in-plane thermal conductivity were further introduced. The h-BN improves the thermal conductivity of the fire warning coating from 1.43 W/m·K to 2.29 W/m·K. Intelligent fire warning sensors with ultra-sensitivity (1.16 s), low response temperature (170 °C), duration time (12 min) and durability (100 cycles) were successfully prepared by improving thermal conductivity to rapidly transfer heat to Ti 3 O 5 , which leads to a rapid decrease in resistance as the core mechanism. This work proposed an ingenious strategy for the construction of high fire safety and thermal conduction fireproof coatings, which revealed enticing prospects in the field of intelligent coatings.
Although traditional fire detectors are widely used in many occasions, they still show some limitations, such as slow fire response and poor resistance to severe conditions. Thus, it is urgent to design and exploit early fire-warning device with ultrafast response and flame-retardant ability to provide timely and fast alarm. Herein, graphene oxide paper functionalized with phosphoric acid (GO-PA) is fabricated by a facile and environmentally friendly water evaporation-induced self-assembly approach. Based on the flame-induced electrical resistance transformation characteristic of GO-PA, a fire-warning detector is designed to reliably monitor early fire. Fire alarm can be triggered within 0.5 s when GO-PA samples are attacked by fire. The GO-PA composite paper is more sensitive than GO-based fire sensors reported in the literature. Phosphorus atoms are in situ doped into graphene structure during flame exposure. Combustion reaction of GO is significantly retarded by the incorporated PA , thus fire duration time of GO is greatly improved. This work paves a new way to improve fire detection performance of GO-based sensors. This work provides a guide for the development of advanced fire detection and early-warning sensors to provide reliable and continuous alarm signals.
Wei Tang,Houjie Yu,Dennis W. Hess,Lianpeng Zhang,Xijuan Chai,Kaimeng Xu,Xionghang Yang,Linkun Xie
Wood is a widely used carbon-storing material, but its applications are constrained by vulnerabilities to water, oil and fire. Existing coatings have limited functionalities, failing to meet the intelligent requirements of modern wood products and constructions. Inspired by bionics, a robust superamphiphobic fire sensing EP/F-POS@Fe3O4 coating was designed on wood substrate, fabricated from functional ferroferric oxide (Fe3O4) particles, tetraethyl orthosilicate (TEOS, hydrolyzed into polysiloxane), 1H,1H,2H,2H-perfluorodecyltrimethoxysilane (PFDTMS), and epoxy resin (EP) adhesive. Optimizing the EP content not only enhances coating stability but also engineers surface micronano reentrant structures, endowing the wood with excellent superamphiphobicity (water/oil contact angles >150°). The EP/F-POS@Fe3O4 coating maintains robust hydrophobic and oleophobic properties under sandpaper abrasion, tape peeling, glass bead impact, and knife scratching tests. At the same time, the coating’s effectiveness in reducing the wood’s liquid absorption further confirms its stable water/oil repellency. Importantly, beyond passive flame retardancy, the EP/F-POS@Fe3O4 coating features a breakthrough active fire alarm function: nonconductive under ambient conditions, it acts as a sensor upon flame exposure, exhibiting ultrafast (∼3 s) intelligent visual alarm response and excellent repeatability (>10 cycles), holding potential to mitigate fire risks. Obviously, the EP/F-POS@Fe3O4 coating shows great promise for future applications in wooden architecture and smart furniture.