Zirconium oxides formed by hydrolytic condensation of alkoxides and parameters that affect their morphology

Abstract

When zirconium oxides are formed via hydrolytic condensation of zirconium alkoxides, the particle size and morphology of the resultant zirconia is strongly affected by certain parameters during the condensation. These parameters include: the type of alkyl group in the alkoxide, water/alkoxide ratio, molecular separation of species, and the reaction temperature. The particle size and the morphology in turn affect the sintering behaviour and crystalline transformation of ZrO₂, In this work the parameters that affect the formation of ZrO₂ from zirconium alkoxides are investigated. It has been shown that the alkyl groups and molecular separations during the hydrolytic polycondensation have particular significance in the modification of monoclinic → tetragonal transformation of the resultant ZrO₂. Tetragonal phase can also be stabilized by copolymerization of ZrO₂ with SiO₂ producing tough ceramic materials.