气相法二氧化硅的表面改性

Surface Modification of Fumed Silica

以气相法二氧化硅为原料,六甲基二硅氮烷为改性剂,采用干法工艺对气相法二氧化硅表面进行改性,探讨了六甲基二硅氮烷用量、反应温度、反应时间对气相法二氧化硅表面改性效果的影响。结果表明,当六甲基二硅氮烷用量为气相法二氧化硅质量的25%、反应温度为150℃、反应时间为40 min时,二氧化硅表面的硅羟基数量最少,比改性前减少97%。

The surface of fumed silica was modified by dry method with hexamethyldisitazane as modification agent. The effects of factors such as hexamethyldisilazane content, reacting time and temperature on the surface modification of fumed silica were investigated. The results showed that when the weight of hexamethyldisilazane was 25% of fumed silica, reacting temperature was 150℃ , reacting time was 40 minutes, the number of hydroxyl groups on the surface of silica was lowest, approximately 97% less than unmodified.