Effekts of Temperature and Reactant Concentration on Properties of Fine TiO2 Particles Prepared by Vapor-Phase Hydrolysis of Titanium Teiraisopropoxide

ABSTRACTSubmicrometer-size TiO2 powders were continuously produced by vapor-phase hydrolysis of titanium tetraisopropoxide, TTIP, in a tubular-flow reactor. Particle size increased with increasing inlet TTIP concentration, and with decreasing inlet water concentration and temperature. At high water concentrations, primary particles form by instantaneous chemical reactions and particle growth occur by collision and coalescence of the particles. Brownian collision and coalescence theory could predict the experimental effect of inlet TTIP concentration on particle size. The experimental deviations occurred from the theory with increasing temperature were attributed to the changing particle properties with temperature.