Change of Particle Size of Spherical Alumina Powders Prepared by Emulsion Method in the Region of Low Hydroxypropylcellulose Concentration

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J. Korean Ceram. Soc. > Volume 32(5); 1995 > Article

Journal of the Korean Ceramic Society 1995;32(5): 594.

저농도의 HPC 영역에서 에멀젼법에 의해 제조된 구형 알루미나 분말의 입자 크기 변화

안치원, 박건식, 유한수, 조건, 이영우¹, 양명승¹

한국과학기술원 무기재료공학과
¹한국원자력연구소

Change of Particle Size of Spherical Alumina Powders Prepared by Emulsion Method in the Region of Low Hydroxypropylcellulose Concentration

ABSTRACT

Spherical alumina gel powders were produced by hydrolysis of aluminum sec-butoxide (Al(sec-OC4H9)3) in a n-octanol/acetonitrile mixed solvent. The enlargement of particle size was induced by increasing HPC (hydroypropylcellulose) concentration (0.005, 0.1, and 0.05 g/ι) and emulsion-state aging time (10 min and 360 min). Mean particle sizes of dried alumina gel powders increased from 1.4 ${mu}{textrm}{m}$ to 3.5${mu}{textrm}{m}$ at 10-min emulsion-state aging time and from 1.9${mu}{textrm}{m}$ to 4.1${mu}{textrm}{m}$ at 360-min emulsion-state aging time as HPC concentration increased from 0.005 g/ι to 0.05 g/ι. At the same HPC concentration, particle size of dried alumina gel powder increased with increasing of emulsion-state aging time from 10 min to 360 min. The increase in the average particle size of dried alumina gel powder with increase in HPC concentration was interpreted as the enlargement of particles from alkoxide emulsions unprotected by HPC. The produced dried gel powder calcined at 115$0^{circ}C$ for one hour transformed to $alpha$-alumina.

Key words: Alumina, Powders, Particle size distribution, Emulsion, Sol-gel process