The Characteristics of Nanosized TiO2 Powder in Chemical Vapor Condensation

Abstract

The effect of the ratio of O-2/He flow rate in the reactor on the characteristics of nanosized TiO2 powder synthesized by chemical vapor condensation process was investigated under fixed conditions of supersaturation ratio, collision rate and residence time. As the ratio of O-2/He flow rate increased, the particle size of TiO2 powder almost remained unchanged but the agglomeration of nanoparticles enlarged in which the degree of agglomeration was defined as the ratio of particle size to crystallite size. Based upon the reaction of Ti(OR)(4)+18O(2)-->TiO2+14H(2)O+12CO(2), it is presumed that the water vapor released from the reaction of precursor with oxygen gas is responsible for the particle agglomeration.