摘要
探讨了文题的方法,研究了反应物浓度、搅拌速率、溶剂与底物类型对水解速率与粒子性能的影响规律。粒子平均直径D_V随着反应底物浓度的增加而增加,随着水浓度增加而降低,粒径分散度GSD随着底物和水浓度增加而变窄;搅拌强度增大,D_V增加,分布变宽;溶剂中配位基电负性愈低,D_V愈大,当溶剂与反应底物中的配位基相同时,GSD最佳。底物中配位基的电负性愈高,其水解动力学稳定性愈差,D_V愈小。实验制备的TiO_2超细粒子为无定形态,球状,D_V=100～400nm,CSD=1.1～1.4,且化学纯度高。
The process of preparation of TiO_2 ultrafine particles by hydrolysis of metal alkoxides is described in detail. The effects of the concentration of reactants, the types of solvents and organometallics as well as stirring rate on hydrolysis rate and particle properties were studied. The mean particle size increased with increasing concentration of titanium alkoxides, but decreased with larger amount of water and higher stirring rate, and its distri-bution got narrower with increasing concentration of reactants, but got wider with higherstirring rate. The lower the electronegativity of the ligand in solvent molecules, the larger the mean particle size. If solvent molecules and reactant molecules have the same ligand, the uniformity of panicle size is best. When the electronegativity of ligand in reactant molecular is higher, its dynamic stability of hydrolysis is poorer, and the particle size, hence, is smaller. The particles prepared are fine (D_v=100～400 nm), of uniform-size (GSD=1.1～1.4), spherecal, amorphous and of high-purity.
基金
高等学校博士学科点专项科研基金
关键词
氧化钛
烷氧基钛
水解
粒子
titanium oxide
ultrafine particles
hydrolysis of metal alkoxides
particle size and its distribution
electronegativity of ligand
