Formation of Spherically Aggregated ZrO₂ Particles by Thermal Hydrolysis of ZrOCl₂ Concentrated Solution

Abstract

Spherically aggregated ZrO₂ particles of about 1μm with narrow size distribution were obtained by hydrothermal treatment of highly concentrated ZrOCl₂ solutions at 200°C following the heat-treatment at 300°C in air to dry. The aggregates are joined each other and are easily collapsed and dispersed to ultrafine particles of smaller than 10nm by adding water before drying. The powder composed of the aggregates maintaining the shape as well as formed at the stage of the hydrothermal treatment was obtained when the ‘double structured vessel’ was employed for the hydrothermal treatment.