水和ジルコニア微粒子の核生成及び結晶成長過程に及ぼすpHの影響

抄録

The formation retes of monoclinic hydrous-zirconia particles produced by the hydrolysis of ZrOCl₂ solutions with and without an addition of aqueous ammonia or anion-exchange treatment were measured to clarify the effects of pH on the nucleation and crystal growth processes of hydrous zirconia. At pH ranges below 1.2, the crystal growth rate of primary particles of hydrous-zirconia increased monotonously with increasing pH, but the nucleation rate was independent of pH. When the pH was kept at around neutrality, amorphous hydroxide formed. The tendency of crystal growth rate of primary particles to increase at low pH can be explained by the blocking action for crystal growth of Cl^- ions attracted on the particle surface, through the formation of an electric double layer.