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.

摘要：

以正硅酸乙酯为原料，在超声波作用下采用醇盐水解法制备了超微SiO₂粉体，并采用XRD、SEM、FT-IR和DTA研究了SiO₂样品的物相、微观形貌、基团结构和热稳定性。结果表明，超微SiO₂粉体为规则的单分散球形非晶态颗粒、粒度均匀、粒径范围窄。样品中含有大量羟基，可加热脱除。SiO₂粉体在1150℃发生晶形转变，1200℃转变完成，生成方石英晶相。通过在制备过程不同阶段取样测试，分析了球形SiO₂颗粒的生长机理。