Preparation and Thermodynamic Study of Self-Dispersal Nano-AlOOH

Self-dispersal nano-AlOOH crystal powder was prepared via sol-hydrothermal crystallization and charging method, using aluminum salt and ammonium as raw materials. TEM, XRD and UV-vis absorption spectroscopy were used to study effects of the hydrothermal temperature and hydrothermal time on precursor's crystallization and charging, the product's dispersion property and mean particle size. Thermodynamic and dynamic analysis on the preparation process was carried out. Results and analysis suggested that the influence of hydrothermal temperature on product's dispersion property was larger than that of hydrothermal time. Modification and control of the hydrothermal conditions could make AlOOH crystal grow along the C-axis and form needle-like particle with lowered surface energy and improved dispersion property. Thermodynamic analysis suggested that the phase transition from Al2O3[whitesquare]nH2O into crystalline AlOOH could spontaneously occur at a temperature within the range of 100oC - 150oC. In the preparation of AlOOH crystal powder via the hydrothermal crystallization and charging composite dispersion method, the reaction condition was mild with a strong thermodynamic driving force and small activation energy of 24.11kJ/mol.