准单分散球形二氧化钛颗粒的可控制备研究

采用表面活性剂辅助的溶胶-凝胶法制备了粒径在200～900nm之间可调控的球形TiO₂颗粒. 基于SEM、TEM、XRD、氮气吸附-脱附等分析手段, 系统研究了不同种类和链长的非离子表面活性剂ODA、Span-80、F-127、PEG系列对颗粒粒径和分散性的影响, 结果表明TiO₂颗粒的形貌、粒径及尺寸分布与所加入表面活性剂分子的空间位阻有关. 对于同一种类型的表面活性剂, 所加入分子的空间位阻越大得到颗粒的形貌越规则、颗粒的粒径越小、单分散性越好. BET分析表明, 加入F-127及PEG-20000所得到的TiO₂颗粒经500℃处理后具有介孔结构, 平均孔径分别为3.4和2.6nm.

Controllable Preparation of Quasi-monodispersed Spherical Titania Particles

Quasi-monodispersed spherical titania particles with variable sizes were prepared by the solgel synthesis with the addition of surfactant. The particles were characterized by the scanning electron microscope, transmission electron microscope, X-ray diffraction and nitrogen absorption. The influence of surfactant of ODA, Span-80, F-127 and PEG with various molecular weight on the morphology, the size, and the size distribution of particles was investigated respectively. The research results show that the steric hindrance of surfactant is very important to morphology, size and size distribution of titania particles. Perfect spherical particles can be obtained when the steric hindrance of surfactant is big enough. Nitrogen absorption measurements reveal that titania particles synthesized by addition of F-127 or PEG-20000 possess meso-pore structure, and the pore diameter is about 3.4nm and 2.6nm, respectively.