Wallpaper can be a serious contributor to house fires, since it’s often highly flammable and helps spread flames faster throughout a building. But scientists are experimenting with a new type of wallpaper that isn’t just flame-resistant, but actually detects fires with the help of graphene. Just like your average wallpaper, the stuff can be manufactured in different colors and printed commercially for designers and decorators, but it contains none of the potentially hazardous flame retardant chemicals with which most wallpaper must be treated.
The wallpaper comes from China’s Shanghai Institute of Ceramics, where Professor Ying-Jie Zhu and his team are experimenting with graphene applications. Their research, recently published in the journal ACS Nano, describes how they weaved the wallpaper using two types of inorganic materials. The first is ultra-long hydroxyapatite nanowires, which are tiny threads made from a mineral form of calcium apatite commonly found in teeth and bones. The other one is threads of graphene oxide, a form of graphene that can be mixed with other materials.
Both materials are fire-resistant, but it’s the latter that turns this fire-resistant wallpaper into a fire alarm. That’s because graphene oxide is an electrical insulator at room temperature–but when it’s heated to high temperatures, it becomes conductive. In their design, graphene oxide sensors woven into the wallpaper are connected to an alarm system. When it’s exposed to heat, the circuit is closed and electricity moves through the system–setting off the alarm.
It’s impressive–albeit still experimental–research. The question on my mind, though, is how will I shut the wallpaper up like I do the smoke detector every time I cook?