Foam stability properties of eco-friendly three-phase foam system reinforced by polydopamine@KH560/ (octyl)-trimethoxysilane modified basalt

To achieve high stability of foam extinguishing system, basalt(BAS) was first modified and added to form a three-phase foam system in this study. Firstly, the polydopamine(PDA) was coated on the surface of BAS. After that, the γ-(2,3-epoxypropoxy)propytrimethoxysilane(KH560) and (Octyl)-trimethoxysilane (OTMOS) were further grafted on the BAS surface to improve the dispersion and hydrophobicity. the modified results were verified by FT-IR, TG, and XRD. Secondly, factors including the surfactant type, concentration, temperature, and the mass concentration of solid particles were also studied. The results indicated that the foam performance of sodium dodecyl sulfate(SDS) was better than other surfactants. Within a certain range, the foam performance enhanced with the increasing stirring speed, time, and solid mass concentration. Moreover, the stability of the three-phase foam fire extinguishing agent added with modified BAS was significantly improved compared with the two-phase foam, and the 50% drainage time reached 28.03 mins, which was more than 4 times that of the two-phase foam. Hence, the optimized basalt eco-friendly three-phase foam is expected to play an effective application in the fire extinguishing and prevention of huge fires. [Display omitted] •Basalt(BAS) was modified by dopamine coating and in-situ grafting.•The method employed an environmentally friendly surfactant as a two-phase system.•The influence of process parameters on foam properties was discussed.•The obtained BAS has high performance in foam stabilization.