Abstract: A new environment-friendly foam extinguishing agent composed of xanthan gum, nano-silica particles and compound surfactants is proposed to quickly extinguish flammable liquid fires. The surface properties, aggregation characteristics and foaming behavior of foam extinguishing agent were studied by fluorescence spectrophotometer, droplet shape analyzer, lubricant anti-foam property tester and binocular transmission polarization microscope. The results showed that the stability of the foam remained above 85% with the addition of xanthan gum and silica nanoparticles. Through the foam performance test, the best foam performance is matched, the initial foam volume is 905 mL, the 25% drainage time is 300 s, and the displacement is 105 mL within 10 min. The foaming performance and foam stability of the foam are significantly improved. Subsequently, by using the formula to carry out small fire extinguishing experiments, the fire extinguishing time is 18 s, and the reignition time is 650 s, this fire extinguishing agent has the potential for fire protection applications.

Key words: fluorine-free foam, nano-silica, xanthan gum, pyrene fluorescent probe, foam property