Development and characterization of fluorosilane-modified expandable graphite for fire suppression

In this paper, a modified material EG-PR with hydrophobic and oleophobic properties was successfully prepared with expanded graphite (EG) as the main raw material and 1H,1H,2H,2H-perfluorodecyltrimethoxysilane (PR) and silane coupler KH-570 (KH) as surface modifiers. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy verified the effective modification that produced a Si‒O‒Si network structure. The water contact angle (WCA) of 127° and oil contact angle (OCA) of 110° of EG-PR, unmodified EG-IA, were 92° and 20°, respectively. Fire-extinguishing tests conducted on heptane pool fire showed that EG-PR decreased the time required to extinguish the fires by 23 s, consumed less extinguishing agent, and suppressed the production of carbon dioxide during combustion compared to EG-IA, indicating its higher effectiveness. EG-PR demonstrated rapid fire-extinguishing capabilities during the experiments. It effectively extinguished the flames, created a protective layer on the oil pool’s surface, efficiently isolated heat and oxygen, and effectively suppressed flame propagation on the surface. This study highlights the potential of surface-modified expandable graphite in enhancing fire safety applications.