Abstract:

With Si(OC₂H₅)₄ as raw material, ultrafine SiO₂ powder was prepared by the alkoxide-hydrolysis method under ultrasonic irradiation.XRD, SEM, FT-IR and DTA were used to characterize the phase, micro-morphology, functional group structure and thermal stability of SiO₂ powder.The results indicated that the regular mono-disperse ultrafine spherical SiO₂ particles were amorphous with uniform size and narrow size distribution.There existed much hydroxyl in SiO₂ powder, which could be eliminated by calcining.The crystal form began to transform to cristobalite at 1150℃, and transformation was completed at 1200℃.The growth mechanism of SiO₂ particle was also discussed by observing the morphologies of samples at different stages of the preparation process.