硅水溶胶体系的制备及其性能表征

Preparation and characterization of silica sol without ethanol

以硅酸乙酯(TEOS)为水解前驱体,制备了有机硅水溶胶体系.测定陈化过程中的溶胶粒径,研究反应物浓度、反应温度和电解质溶液对溶胶的形成过程和性能的影响,利用傅里叶红外光谱(FTIR)表征形成的凝胶结构.结果表明:控制反应物中水的用量和反应温度可以改变溶胶的水解速率和聚集速率,使胶凝化时间发生变化;溶胶体系中加入一定量的电解质溶液,能改变溶胶体系的pH值,胶凝时间由6d缩短到2h以内.

Silica sol without ethanol was prepared with tetraethyl orthosilicate （TEOS） as precursor. The particle size of sol during ageing was tested to study the influence of concentration, temperature and electrolyte on the formation and performance of sol. FTIR was used to characterize the gel structure. The results show that the concentration and temperature greatly alter the rates of hydrolysis and condensation reaction and thereby con- trol the gelation time; pH of sol is changed with the addition of electrolyte, and subsequently reducing the gelation time from about 6 d to less than 2 h.