Preparation of α-Al<sub>2</sub>O<sub>3</sub> Platelets from Aluminum Hydroxides Gel

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doi:2004.41.8.610

J. Korean Ceram. Soc. > Volume 41(8); 2004 > Article

Journal of the Korean Ceramic Society 2004;41(8): 610.
doi: https://doi.org/10.4191/kcers.2004.41.8.610

Aluminium Hydroxides Gel을 이용한 α-Al₂O₃ 판상체의 제조

박병기, 이정민¹, 서동수², 임광수³

한국화학연구원 화학공정 연구센터
¹한국화학연구원 화학공정 연구센
²충남대학교 재료공학
³스카이케미칼(주)

Preparation of α-Al₂O₃ Platelets from Aluminum Hydroxides Gel

ABSTRACT

For preparation $alpha$-Al$_2$O$_3$ platelets having 20 $mu$m in average diameter and 0.2∼0.3 $mu$m in thickness, we have prepared aluminum hydroxides gel by using aluminum sulfate and sodium sulfate as starting materials. In this study, we investigated the effect of the amount of sodium phosphate on particle size, morphology and thickness of $alpha$-Al$_2$O$_3$ platelets. When sodium phosphate was not added to aluminum hydroxides gel, most of $alpha$-Al$_2$O$_3$ platelets had hexagonal shape but the thickness was over 1.0 $mu$m, and this sample was not adequate for pearlescent pigment. On the other hand, introduction of sodium phosphate caused an increase of aspect ratio (particle diameter/thickness) with a decrease in $alpha$-Al$_2$O$_3$ platelet thickness.

Key words: Aluminum hydroxides gel, $\alpha$-$Al_2$$O_3$ platelets, Molten-salt method