关键词:

超声水热, 单分散, 正交实验, 水解, 缩合, 非晶态

Abstract:

Mono-disperse spherical silicon dioxide was synthesized in 2-propanol-H₂O-NH₃ system by the ultrasonic hydrothermal method.The catalyst ammonia acted as strong nucleophilic reagent.With orthogonal experiments, the effects of ultrasonic power, reaction temperature, stirring intensity and molar ratio on the size of silicon dioxide were studied.The results indicated that the diameter of silicon dioxide increased greatly with increasing ultrasonic power and molar ratio.The size of silicon dioxide also increased with increasing temperature and stirring intensity, but with a less extent.The process of forming mono-disperse spherical silicon dioxide could be divided into two steps: hydrolysis and condensation, with hydrolysis as the key step.Mono-disperse spherical silicon dioxide was characterized with XRD, TEM, DTA and IR, and the results showed that the sample was noncrystalline with regular shape and uniform granularity and there was a large amount of hydroxyl group in the SiO₂ sample.

Key words:

超声水热, 单分散, 正交实验, 水解, 缩合, 非晶态