溶胶凝胶和超临界干燥法制备纳米TiO_2粉体

PREPARATION OF TiO_2 NANOMETRIC PARTICLE BY SOL-GEL AND SUPERCRITICAL FLUID DRYING METHODS

以钛酸丁酯 (Ti(OR) 4 )为原料 ,采用溶胶凝胶法及超临界流体干燥技术制备了纳米TiO2 粉体。采用正交设计法研究了操作条件对反应的影响 ,筛选出了最佳工艺条件。TEM检测表明 ,优化条件下制得的二氧化钛粉体粒径为 11～ 12 .3nm ,且随热处理温度的升高粒径变化不大 ,但团聚加重。XRD结果表明 ,当热处理温度为 5 0 0℃时晶粒为锐钛型 ;当煅烧温度为 80 0℃时晶粒转化为金红石型。BET结果表明 ,二氧化钛气凝胶颗粒的比表面积可高达5 5 6m2 /g ;但随煅烧温度的升高 ,比表面积下降迅速 ;在 5 0 0℃时 ,比表面积只有 94 .6m2 /g。

Titanium dioxide ulterfine powders were prepared by sol gel and supercritical fluid drying methods taking tetrabutoxytitanium as raw material, and the powder was characterized in terms of TEM, XRD, DTA TG, IR and BET techniques. The reaction mechanism and influence factors are discussed. It was found that the ulterfine powders exhibit a small crystallite size of 11～12.3 nm and a high specific surface area of 556 m\+2/g. The treating temperature has a great effect on the crystallite sizes.