Dispersion Properties of Nano Zirconia Sols Prepared by a Hydrothermal Method

摘要

Zirconia was synthesized from zirconium acetate, zirconium nitrate, and zirconium chloride by a hydrothermal method at 150, 200, and 300 degrees C, respectively. The zirconia was dispersed in deionized water for dispersibility studies. The average size, shape, crystal size, and phase of the synthesized nanoparticles were analyzed with a particle size analyzer, transmission electron microscopy, and X-ray diffraction. The crystal size of the synthesized particles is 10-16 nm; however, a crystalline phase was not observed for the zirconia synthesized at 150 degrees C from zirconium acetate. Monoclinic zirconia was obtained at the higher temperatures of 200 and 300 degrees C when zirconium acetate was used as the starting material. A mixture of tetragonal and monoclinic phases was obtained when zirconium nitrate and zirconium chloride were used as starting materials. The average particle size is larger than 100 nm because primary particles aggregated and formed secondary particles. The dispersion behavior of the synthesized zirconia dispersed in deionized water was analyzed in terms of transmittance and turbiscan stability indices. The dispersibility of zirconia synthesized from zirconium acetate and zirconium nitrate at 200 degrees C was better that of zirconia obtained from zirconium chloride according to the particle size and turbiscan analyses. The turbiscan stability index revealed that zirconium acetate produces zirconia particles with the highest dispersion stability.