Preparation and characterization of ultrafine silica powder by microwave hydrothermal method

Ultrafine silica powder was prepared by microwave hydrothermal method using TEOS as raw material and ammonia as catalyzer. The SiO2samples had been characterized by SEM, XRD, DTA, IR and components test. The results showed that ultrafine SiO2powder was amorphous with regularly spheric shape and uniform granularity. There was much hydroxyl in SiO2powder. The prepared SiO2sample had stable thermal performance and the heat-resistant stability below 1100°C. At 1100°C, the amorphous SiO2began to transform to crystal SiO2, and at 1200°C the transformation of crystal had accomplished completely.