板钛矿纳米TiO_2微晶的热分析特性研究

Studyon Thermal Analysis Behavior of Nanocrystalline Brookite TiO_2

对板钛矿纳米TiO2微晶样品（n－TiO2）进行了差热分析（DTA），发现其DTA曲线上出现了A、B两个吸热峰．通过对原始样品及其系列热处理样品进行X射线衍射（XRD）实验，证实A峰对应于物理或化学吸附的脱附过程，B峰完全对应于n－TiO2原始样品结构从板钛矿经锐钛矿向着金红石的一级相变；这一结构相变使成了纳米晶粒的生长．

Using DTA measurement on nanocrystalline brookite TiO2 sample, we found two endothermic peaks on DTA curve. From XRD analysis of the original nanocrystalline TiO2 and its heat-treating samples, we obtained the following results: the first endothermic peak (peak A) corresponds to the desorption of physical or chemical absorption; the second one (peak B) is related to the first order phase transition from brookite to anatase then to rutile, and this structural phase transition is beneficial to the growth of nanocrystallilne grains.