While effective at fighting fires, synthetic extinguishing foams are often toxic and can take over 200 years to decompose. To counter these environmental and safety concerns, a team of chemists from ITMO University in St. Petersburg have developed a firefighting formula based on inorganic silica nanoparticles.
The new foam beats existing analogues in fire extinguishing capacity, thermal and mechanical stability and biocompatibility. After the fire is extinguished, the substance actively absorbs water, softens and falls apart into bioinert silica particles. Should the foam accidentally enter a living organism, it does not pose any danger to them.
The silica nanoparticles create a polymer network when exposed to air, explains Alexander Vinogradov, Laboratory Deputy Head. "Such a network embraces and adheres to the burning object and momentarily cools it down. At the same time, the foam itself hardens and protects the object from reignition, allowing the inorganic material to resist temperatures above 1000 degrees C. (over 1800 degrees F.), which ensures gigantic stability from the aggressive environment in the midst of a raging fire."