Study on the preparation and fire-extinguishing performance of a three-phase aqueous film-forming composite foam material stabilized by CeO2 and xanthan gum

To address the bottlenecks of insufficient long-term stability and poor fire resistance in traditional aqueous film-forming foam extinguishing agents, this study proposes a three-phase aqueous film-forming composite foam material stabilized by the synergistic action of CeO2 and xanthan gum. A blend of the short-chain fluorocarbon surfactant FS-50 and the anionic hydrocarbon surfactant SDS as the base liquid, with nano-CeO2 and xanthan gum as functional additives. The optimal formulation was determined through formulation optimization. Experimental results showed that the surface tension of the composite foam was 17.06 mN/m, the expansion ratio was 7.6 times, the 25% liquid separation time was extended to 190 min. The half-life of the number of bubbles increased from 637 s to 1,517 s. Oil pan fire suppression model tests showed that the three-phase composite foam extinguished the fire in 58 s, with a residual foam thickness of 5.1 mm after extinguishment; the low-level retention time was extended to 500 s, and the collapse resistance time reached 1,152 s. Microscopic and macroscopic mechanism analyses revealed that the xanthan gum three-dimensional network delays liquid film drainage through physical confinement and anchors CeO2 particles at the gas-liquid interface through physical confinement, thereby inhibiting bubble coarsening and coalescence; under high-temperature thermal radiation, CeO2 particles migrate directionally toward the oil/foam interface and enrich in situ, forming a dense inorganic thermal barrier. This study achieved synergistic enhancement of long-lasting foam stability and burn-through resistance, providing a new technical approach for the design of high-performance aqueous film-forming foam extinguishing materials.