含纳米二氧化硅颗粒三相泡沫性能与作用机理研究

为提升水成膜泡沫(AFFF)的灭火性能,基于AFFF泡沫液和纳米硅颗粒,制得新型三相灭火泡沫。实验研究了三相泡沫发泡性和稳定性的变化规律,分析了泡沫组成和工况参数对泡沫性能的影响规律。通过分子动力学(MD)模拟,研究了泡沫溶液中表面活性剂分子吸附对颗粒表面润湿性的影响,揭示了泡沫中颗粒与表面活性剂间相互作用对泡沫稳定性的影响机理。研究发现:随着颗粒浓度增加,泡沫稳定时间和抗烧时间显著增长,而发泡性变化不大。泡沫中颗粒表面润湿性影响颗粒与表面活性剂间的相互作用,进而影响泡沫稳定性。在亲水颗粒泡沫中,表面活性剂浓度增加能够强化二者间的协同作用,利于泡沫稳定;在疏水颗粒泡沫中,随着表面活性剂浓度增加,二者间由协同作用转变成抵抗作用。研究成果对优化三相灭火泡沫配方和提升泡沫灭火效率有指导意义。

Study on properties and mechanism of three-phase foam containing silica nanoparticles

In order to improve the fire-extinguishing performance of AFFF (Aqueous Film Forming Foam), a new three-phase foam has been prepared based on the AFFF foam liquid and silica nanoparticles. The changing rules of the expansion and stability performance of the three-phase foam were studied experimentally, and the effects of the foam composition and operation factors on the foam performance were analyzed. The influence of the surfactants on the surface wettability of the silica particles in the solution was studied by the molecular dynamic (MD) simulation. The influencing mechanism of the interaction between the particles and surfactants in the solution on the foam stability was revealed. It is found that as the particle concentration increases, the foam drainage time and burnback performance increase significantly, while the foaming ability changes little. The wettability of particle surfaces affects the interaction between particles and surfactants in foam, thereby affecting foam stability. In the foam with hydrophilic particles, the increase of surfactant concentration can enhance the synergistic effect between particles and surfactants, which is conducive to the foam stability. While in the foam with hydrophobic particles, as the surfactant concentration increases, the synergistic effect turns into the resistance effect gradually. The results provide theoretical guidance for the optimization of foam composition and operation conditions in the fire-extinguishing process.