Sol-gel法制备纳米TiO2锐钛矿相的晶化动力学

Kinetic Study of the Crystallization of Nano-scale TiO_2 Anatase Prepared by Sol-gel Technique

采用Sol gel技术制备了纳米级锐钛矿TiO2 ,并在 30 0～ 4 5 0℃之间发生了非晶向纳米晶的转变 ,运用非等温结晶过程的计算原理经过数学变换 ,计算了Avrami指数n、晶化激活能E、晶粒长大维数m和晶粒长大激活能Q等动力学参数。结果表明 ,在非晶向纳米晶的转变过程中 ,纳米晶体的特殊结构m对应着独特的动力学性质。

Nanoscale anatase TiO 2 was prepared by a Sol-gel technique. Upon heating, crystallization happened between 300℃ and 450℃. The values of kinetic parameters such as Avrami exponent n, the crystallization active energy E, the dimensionality m and the active energy Q of crystal growth were calculated on the bases of the principle of non-isothermal crystallization processing using differential scanning analysis technique. It is shown that on the course of crystallization, the special structure of nanoscale crystals requires the special kinetic features.