Abstract:

The hydrophobic silica nanoparticles (NPs) were obtained by the modification of NPs with trimethylchlorosilane (TMCS), and the modified NPs were added to fluorine-free foam extinguishing agents to investigate the effects of the different modification agrees NPs on the performance of fluorine-free foam extinguishing agents. Thermogravimetric analysis (TGA), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and water contact angle measurements were used to characterize hydrophobic modified NPs at different TMCS concentrations. The TGA and EDX results confirmed that the effective surface modification of NPs was achieved with TMCS. The water contact angle test results show that when the mass fraction of TMCS is 16.67%. the contact angle of NPs could reach 150.9°. SEM analysis indicated that the dispersion of NPs was improved. The particle size of the modified NPs was mainly distributed between 60—150nm. The results of the foaming property, foam stability and fire extinguishing effectiveness of the modified NPs on the fluorine-free foam solution showed that the modified NPs had the greatest improvement on the foaming property, stability and fire extinguishing effectiveness of the foam when the mass fraction of TMCS was 13.04%.

Key words: trimethylchlorosilane, silica nanoparticles, hydrophobic modification, fluorine-free foam extinguishing agent

摘要：

采用三甲基氯硅烷（TMCS）对二氧化硅纳米颗粒（NPs）进行改性得到疏水NPs，并将改性后的NPs添加到无氟泡沫灭火剂中，研究不同改性程度的NPs对无氟泡沫灭火剂性能的影响。利用热重分析（TGA）、扫描电子显微镜（SEM）、能量色散X射线光谱（EDX）和水接触角等对不同TMCS浓度下表面疏水改性的NPs进行表征。TGA、EDX结果证实TMCS实现了对NPs的有效表面改性。水接触角测试结果表明，TMCS的质量分数为16.67%时，NPs的接触角可达150.9°。SEM分析表明NPs的分散性得到改善，改性后的NPs粒径主要分布在60~150nm之间。改性NPs对无氟泡沫溶液的发泡性、稳泡性和灭火有效性的性能影响的研究结果表明，TMCS的质量分数为13.04%时改性的NPs对泡沫的发泡性能、稳定性能和灭火有效性能有最大的提升。

关键词: 三甲基氯硅烷, 纳米二氧化硅, 疏水改性, 无氟泡沫灭火剂