自分散型纳米AlOOH水热制备纳米α-Al_2O_3粉体

Preparation of Nanometerα-Al_2O_3 Powders by Hydrothermal Treatment of Self-dispersed Nanometer AlOOH

以采用水热晶化与荷电复合分散法制得的自分散型纳米AlOOH作为前驱物、碳酸铝铵热分解得到的纳米α-Al_2O_3作为晶种,利用AlOOH在水中具有良好的自分散性能,采用溶胶均匀分散混料法新工艺,将α-Al_2O_3晶种均匀分散到纳米γ-AlOOH晶体的溶胶中,在190℃水热下,使AlOOH转变成氧化铝,经930℃煅烧得到平均粒径为60nm的纳米α-Al_2O_3。利用XRD、TEM等手段分析研究了前驱物微细化及其分散性能对晶种的作用和氧化铝转型温度的影响。

Nanometer α-Al2O3 powder is prepared by a synthesis process, using the self-dispersed nanosized A1OOH obtained by the hydrothermal crystallization and charging composite dispersion method as precursors and the α-Al2O3 nanocrystal obtained from pyrolyzing ammonium aluminum carbonate hydroxide as seeds. Based on the good self-dispersion of the AlOOH in water, the α-Al2O3 seeds are dispersed evenly into the AlOOH sol by the new homodispersion mixing technique. This process enables the conversion of AlOOH to alumina at 190℃ （hydrothermal temperature）, in which the alumina is calcined to nanometer α-Al2O3 having an average diameter of 60nm at 930℃. The effects of superfine pulverization and self-dispersivity of the precursors on the action of crystal seeds and the phase inversion temperature of alumina are studied by XRD and TEM.