To precipitate the complex gel of a flux and an aluminum hydroxides gel, an aqueous solution of a mixture of Na2CO3 and Na2PO4 center dot 12H(2)O was added with stirring into an aqueous solution of a mixture of Al-2(SO4)(3)center dot 18H(2)O, Na2SO4 and K2SO4, and then the complex gel was aged in 0 similar to 30 h at 90 degrees C. As aging time passed, the aluminum hydroxides contained in the complex gel were grown to a acicular AlO(OH) nano gel. Also, aging time had an effect on the physical properties of the AlO(OH) nano gel and on the crystal growth of the alpha-Al2O3 platelets prepared by molten-salt precipitation. In this study, the complex gel was crystallized in the temperature range of 400 similar to 1,200 degrees C and after drying at 110 degrees C, the effect of aging time on precipitation temperature, the size, thickness, morphology and particle size distribution of the alpha-Al2O3 platelets were investigated. As aging time passed, the alpha-Al2O3 platelets showed a tendency toward an increase in size and thickness as a result of an increase in BET surface area and pore volume of the AlO(OH) nano gel.

Keywords: AlO(OH) gel; alpha-Al2O3 platelets; molten salt precipitation; pearlescent substrate; insulator