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讨论了采用溶胶 -凝胶法经由先驱物钛酸四异丙脂水解而制备的纳米TiO2 粉末的结构相变 ,并讨论了该纳米粉末的生长动力学机理 .结果表明 ,水解pH值为 0 9,当高压釜热处理温度 <5 0 3K时 ,粉末晶粒度增长较为缓慢 ,而当热处理温度 >5 0 3K时 ,粉末粒度明显长大 .应用相变理论计算出了纳米TiO2 颗粒的两阶段的生长激活能 ,分别是 18 5kJ mol和 5 9 7kJ mol.XRD物相分析表明 ,高压釜热处理温度达到 5 0 3K时 ,样品就开始发生锐钛矿到金红石相的结构相变 ,到 5 4 3K就基本实现了这一结构相变 ,使得这一相变温度比其他文献中报道的又降低了许多
The phase transition of nano-TiO2 powder prepared by sol-gel method via hydrolysis of tetraisopropyl titanate titanate was discussed, and the growth kinetics mechanism of the nano-TiO2 powder was discussed. The results showed that the hydrolysis pH value was 0 9 , When the autoclave heat treatment temperature <5 0 3K, the growth of the grain size of the powder is relatively slow, and when the heat treatment temperature> 500K, the particle size of the powder obviously grows.Using the phase change theory to calculate the nano-TiO2 particles two-stage The growth activation energies were 18 5kJ mol and 597kJ mol respectively.XRD phase analysis showed that when the autoclave heat treatment temperature reached 500K, the sample began the structural transformation from anatase to rutile phase, The structural phase transition is basically achieved, making this phase transition temperature much lower than reported in other literature