摘要
以钛酸四丁酯、醋酸钡和冰醋酸为原料 ,利用溶胶 -凝胶工艺经水解、聚合生成钡钛醋酸盐 ,经煅烧制成 Ba Ti O3纳米粉末 .研究了溶胶体系初始 p H值及胶凝温度对钛酸四丁酯 -醋酸钡 -冰醋酸体系溶胶 -凝胶转变过程的影响 ,以及溶胶 -凝胶转变过程中的流变特性 .实验结果表明 ,溶胶体系初始 p H值的变化不仅影响溶胶 -凝胶的转化进程 ,而且影响煅烧后 Ba Ti O3纳米粉末的粒径大小 .在 2 0℃、初始 p H值为 3 .8和 5 .3的溶胶 ,其转化为凝胶所需时间分别为 40和 1 2 0 h;凝胶经 80℃干燥 ,70 0℃煅烧所得 Ba Ti O3纳米粉末的平均粒径分别约为 90和 70 nm.
The clear and transparent sols of BaTi acetate were prepared from tetrabutyltitanate, barium acetate aqueous solution, ethanol and acetic acid. The BaTi acetate sols were transferred into gels by sol gel process, and the gels were dried and calcined to nanostructured BaTiO 3 powders. The sol gel transition process has been investigated as functions of initial pH value of sol, time and temperature of gel for the tetrabutyltitanate barium acetate acetic acid system. The rheological behavior occurred in the sol gel transition have been investigated. It is found that the initial pH value of the sol affected not only the sol gel transition, but also the particle size of the final calcined BaTiO 3 powders. For the BaTi acetate sols with initial pH values of 3 8 and 5 3, the time from sol to gel was 40 and 120 h at 20 ℃, respectively; after dried at 80 ℃ and calcined at 700 ℃, the grain size of BaTiO 3 powders was 90 and 70 nm, respectively.
出处
《应用化学》
CAS
CSCD
北大核心
2002年第5期450-454,共5页
Chinese Journal of Applied Chemistry
基金
天津市青年科学基金资助项目 (993 70 12 11)
关键词
钛酸丁酯-醋酸钡-冰醋酸体系
溶胶-凝胶转变
PH值
流变特性
tetrabutyltitanate barium acetate acetic acid system,sol gel transition process,pH value,rheological behavior
