异丙醇钛控制水解的小角X射线散射研究

由金属醇盐水解制备溶胶的方法已广泛应用于溶胶-凝胶法制备纳米孔无机膜，但对金属醇盐水解机理的认识十分有限。通过控制异丙醇钛Ti（i-OC₃H₇）₄]在异丙醇（i-C₃H₇OH）中水解制备TiO₂溶胶，利用小角X射线散射（SAXS）方法研究了由不同H₂O/Ti（i-OC₃H₇）₄的反应混合物Ti（i-OC₃H₇）₄：H₂O：i-C₃H₇OH=1：m：30（摩尔比）]形成TiO₂溶胶的过程，探讨了控制Ti（i-OC₃H₇）₄水解的过程中胶粒形成与长大的规律。研究结果表明，所合成的TiO₂溶胶的胶粒粒径小于10 nm，胶粒的形成和长大与H₂O/Ti（i-OC₃H₇）₄摩尔比密切相关。H₂O/Ti（i-OC₃H₇）₄（摩尔比） ≥ 2.0时，随着H₂O/Ti（i-OC₃H₇）₄增加，溶胶的稳定性下降。

Study on controlled hydrolysis of titanium isopropoxide by small angle X-ray scattering

Metal oxide sols can be prepared from metal alkoxides by hydrolyzation, which has been widely used in synthesis of nano-porous ceramic membranes by sol-gel method. However, the knowledge on hydrolysis mechanism of metal alkoxides is very limited. In this paper, TiO₂ sols were prepared by controlled hydrolyzation of titanium isopropoxideTi(i-OC₃H₇)₄] in isopropanol (i-C₃H₇OH). The formation of TiO₂ sols from the initial reactant mixtures with different molar ratios of H₂O/Ti(i-OC₃H₇)₄Ti(i-OC₃H₇)₄:H₂O:i-C₃H₇OH=1:m:30] was charterized by small angle X-ray scattering (SAXS). The mechanism of formation and growth of colloidal particles is discussed. TiO₂ sol with a particle size less than 10 nm can be obtained. The formation and growth of colloidal particles are remarkably influenced by the molar ratio of H₂O/Ti(i-OC₃H₇)₄. When the molar ratio of H₂O/Ti(i-OC₃H₇)₄ ≥ 2.0, the stability of TiO₂ sol decreases with the molar ratio of H₂O/Ti(i-OC₃H₇)₄ increasing.