Effect of Hydrolytic Temperature on Pore Structure of Alkoxide-derived Aluminas

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J. Korean Ceram. Soc. > Volume 25(3); 1988 > Article

Journal of the Korean Ceramic Society 1988;25(3): 217.

Alkoxide 법으로 합성한 알루미나의 동공구조에 미치는 가수분해 온도의 영향

조정미, 정필조¹

성신여자대학교 화학과
¹한국화학연구소 무기화학부

Effect of Hydrolytic Temperature on Pore Structure of Alkoxide-derived Aluminas

ABSTRACT

Pore structures of Alkoxide-derived aluminas are investigated by BET Nitrogen Sorption method. Aluminas are derived from hydrolysis of aluminum isopropoxide at 3$^{circ}$and 8$0^{circ}C$ with stoichiometric quantities of water in use. The resulting hydrolysates are then subjected to thermal treatment for a fixed period of time from 200$^{circ}$to 50$0^{circ}C$ in gradual fashions. The hydrolysates obtained at 3$^{circ}C$ increase their pore volumes with increasing heat treatment, exhibiting their pore-size distributio as twinpeaked. In contrast, the reverse is true to the hydrolysates obtained at 8$0^{circ}C$, showing their pore size distribution as single-peaked. This suggests that the pore shapes of the former shall be slit-shaped, whilst whose as the latter shall be of a ink-bottle shape. All the evidence indicates that the hydrolytic temperatures play an important role not only in determining the pore shapes of the alumina samples, but in controlling the liberation of structural water in the alumina layers. It is also, surmized that the subsequent heat treatment may at best affect the mode of pore size distribution for the resulting alumina product(s).