正硅酸乙酯溶胶-凝胶行为的超声波原位监测研究

Ultrasonic In-situ Monitoring on Ethyl Orthosilicate Sol-gel Behavior

利用超声波原位监测的方法,研究了酸催化条件下正硅酸乙酯的溶胶-凝胶行为,得到信号特征值随反应的变化曲线,结合红外和电镜图谱,对结果进行了分析。研究表明,低温利于水解,高温利于缩合,80℃的反应温度相对适合;相同温度下,当H2O/TEOS=8∶1时,正硅酸乙酯水解-缩合的过程最短。由此考察了超声波监测信号特征值变化与正硅酸乙酯溶胶-凝胶反应过程的联系,可获得过程中粒子形成、粒径变化、反应程度以及凝胶生成等信息,提供了一种材料制备过程中实时在线的监测和研究手段。

The ultrasonic in-situ monitoring method was used to investigate the ethyl orthosilicate（TEOS） sol-gel behavior first under the acid catalysis condition,obtaining the signal characteristic curve along with the response change.The infrared spectrometry and the SEM were carried on the analysis to the results.It indicates that,high temperature favors the condensation,the sol-gel process is shorter when H2O/TEOS=8∶1 under the same temperature.The real-time signal attenuation increases rapidly,appears the peaks,then gradually reducing tends to achieve a platform,latterly increases to occur jumps.Through inspecting the ultrasonic signal change,it can obtain the information about the granule growth,particle size change,extent of reaction and gelatin to form.It offers a sort of real-time monitoring research method,providing the important reference for further understanding the silicon dioxide and the compound materials preparation.