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염화알미늄 증기의 부분가수분해를 통한 알파 알루미나 나노입자 제조
박회경 ( Hoey Kyung Park ),유연석 ( Youn Sug Yoo ),박균영 ( Kyun Young Park ),정경열 ( Kyeong Youl Jung ) 한국화학공학회 2011 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.49 No.5
Spherical alumina precursors represented by (AlO)x(Cl)y(OH)z, 30~200 nm in particle diameter, were prepared by partial hydrolysis of AlCl3 vapor in a 500 ml reactor. Investigated on the particle morphology and size were the effects of the reaction time, the stirring speed and the reaction temperature. The particle morphology and size was insensitive to the reaction time in the range 20 to 300 s. The variation of the stirring speed from 0 to 300 and 800 rpm showed that the particle size was the largest at 0 rpm. As the temperature was varied from 180 to 190, 200, 140 °C, the particle size showed a maximum at 190 ˚C. By calcination of the as-produced particles at 1,200 °C for 6h with a heating rate of 10 °C/min, α-alumina particles 45 nm in surface area equivalent diameter were obtained. The particle shape after calcination turned wormlike due to sintering between neighboring particles. A rapid calcination at 1400 °C for 0.5 h with a higher heating rate of 50 °C/min reduced the sintering considerably. An addition of SiCl4 or TMCTS(2,4,6,8-tetramethylcyclosiloxane) to the AlCl3 reduced the sintering effectively in the calcination step; however, peaks of γ or mullite phase appeared. An addition of AlF3 to the particles obtained from the hydrolysis resulted in a hexagonal disc shaped alumina particles.
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