Surface Modification of Fumed Silica

The surface of fumed silica was modified by dry method with hexamethyldisilazane 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.