粒径可控球形TiO2的制备

在正丙醇与水的混合溶剂体系中以Ti(SO4)2为前驱物制备得到了粒径分布窄, 分散性好的球形TiO2. 对表面活性剂种类及用量, 反应物浓度及焙烧温度和时间等影响因素进行了研究, 结果表明, 在正丙醇与水的体积比为1:1的条件下, 以聚乙烯吡咯烷酮(PVP)为表面活性剂, 温度为70-90 ℃时可制得粒径分布窄、分散性好的高质量的球形TiO2颗粒. 通过TG-DSC、SEM、XRD等分析表明, 颗粒粒度大小及粒径分布受表面活性剂浓度和反应前驱物浓度影响大; 物相间的转化主要由焙烧温度和时间来决定. 并引入LaMer模型对颗粒形核、长大的过程进行理论说明.

Preparation of the Size-Controlled TiO2 with Spherical Morphology

Spherical Titania (TiO2) with narrow size distribution and nice dispersibility was obtained by hydrolysis in the mixed solvent of 1-propanol and de-ionized water from titanium sulfate (Ti(SO4)2). Parameters like surfactant, precursor concentration, calcination temperature, and calcination time were investigated. The results showed that high quality TiO2 could be synthesized using polyvinylpyrrolidone (PVP) as surfactant when the volume ratio of 1-propanol to de-ionized water was 1:1 at 70-90 ℃. And the optimal surfactant concentration had an important impact on the size distribution and dispersibility. The products were characterized by TG-DSC, SEM, and XRD. The results displayed that the size and size distribution of the particles were affected by the surfactant concentration and the precursor concentration. However, phase transformation of TiO2 was mainly determined by calcination temperature and time. And a LaMer model was introduced to explain the nucleation and growth of the TiO2 particles.