Phase Transition Activity Characteristics of Nanosized AlOOH in the Hydrothermal Synthesis of Nanosized α-Al2O3
α-Al2O3 nanopowders were prepared by a novel synthesis process, using the nanosized α-Al2O3 obtained from pyrolyzing ammonium aluminum carbonate hydroxide as seeds and the self-dispersed nanosized AlOOH crystal powders as precursors. Based on their good self-dispersion in water, the α-Al2O3 seeds were dispersed evenly into the AlOOH sol by the new homodispersion mixing technique. This process enables the conversion of AlOOH to alumina at 190°C (hydrothermal temperature), in which the alumina is calcined to nanosized alpha-alumina having an average length to diameter ratio of 60nm:15nm at 930°C. In the synthesis reaction for transforming the AlOOH to alumina, the effect of superfine pulverization and self-dispersion of the precursors was studied.
Wei Pan and Jianghong Gong
H. D. Liao et al., "Phase Transition Activity Characteristics of Nanosized AlOOH in the Hydrothermal Synthesis of Nanosized α-Al2O3", Key Engineering Materials, Vols. 368-372, pp. 675-678, 2008