1996 年 104 巻 1210 号 p. 540-544
The effects of the concentration of titanium (IV) chloride solution, aging temperature and time, and the pH of solution on the morphology and size of hydrous titanium (IV) oxide fine particles formed by a colloid aging method were studied in detail. Cube-shaped particles of 0.20μm in size were formed by aging 2.5×10-2mol·dm-3 titanium (IV) chloride solution at room temperature for 5d. The cube-shaped particles were easily attained by decreasing the titanium (IV) chloride concentration and/or increasing the aging temperature. The aging of 5.0×10-2mol·dm-3 titanium (IV) chloride solution with urea at 90°C for 20h gave needlelike-shaped, cube-shaped, and spherical particles in the ranges of pH<1, 1≤pH<2 and 6<pH, respectively. Cube-shaped particles of 0.24μm in size used as seeds were successively grown to 0.38μm in size under the same aging conditions described above except without urea. It is concluded that both the chloride ion and the pH of solution play an important role on the formation of cube-shaped hydrous titanium (IV) oxide fine particles.