Recrystallization of nanosized boehmite in an aqueous medium

The formation and subsequent recrystallization of nanoboehmite under hydrothermal treatment of γ-Al2O3 nanopowder at a temperature of 150 °C in a 1.5% HCl solution have been studied. It has been found that boehmite nanowhiskers up to 2–3 μm in length and no more than 50 nm in diameter are formed from the crystals with a size of 10–20 nm, when kept them under synthesis conditions for up to 96 h. In the course of recrystallization, it was found that unit cell parameters of boehmite depend on time of thermal processing of samples. It has been concluded the solid-phase mechanism of recrystallization and the important role of the hydrothermal medium in the redistribution of elements of the crystal structure.