Fire hazard is one of the major disasters that threaten public safety seriously. Once a fire occurs, the fire will spread quickly along some flammable materials, which bring much difficulty to control the fire. The fire hazard will cause casualties, considerable property loss and medical costs. Meanwhile, destructive volatiles would have influence on surrounding environment and global climate. Fire warning system can send a signal in the early stage of fire, which will earn time for fire control. However, early fire alarms are triggered only after fire encounters, and the timeliness and sensitivity are severely insufficient, as well as other defects. Therefore, design and development of efficient fire alarms still have certain challenges.
Graphene oxide (GO), one kind of two-dimensional materials, has special surface properties, layered structure and excellent water dispersion, which has been used in many fields. And GO can be reduced to form graphene with low resistivity and high electron mobility, which has been used in electricity field. Normally, there are many methods to achieve reduction of GO. High temperature thermal reduction is one among them. Therefore, prepare fire alarms system in my work based on high temperature combustion way to reduce GO to conductive graphene.
In my current work, cellulose paper is chosen as matrix to design fire alarm. Cellulose paper after coating phytic acid is endowed flame-retardant property. MCC results show about 85.9% decrease of HRR in comparison of pure cellulose paper. During combustion process, pure cellulose paper burns out. But paper with phytic acid is self-extinguish. All this mean cellulose paper after modification display good flame retardant, which provide basis for the formation of conductive pathway. Try using GO solution in preliminary work. Cellulose paper with phytic acid is immersed into GO solution for loading different concentration of GO. The rapid response behavior is based on the change of electrical resistance causing by GO structure, which is caused by the formation of electrical conductivity graphene from the reduction of electrical insulation during high temperature process.
The initial work has verified the feasibility of designing fire alarm system. And in the future work, more work will focus on how to cut down response time to achieve fast responding and increase the response time to improve the stability of fire alarm.