Mechanism of the Conversion of γ-Al2O3 Nanopowder into Boehmite under Hydrothermal Conditions

We have developed a method for the preparation of boehmite (AlOOH) nanopowder with tailored properties (particle size from 10 to 40 nm, thermal conductivity below 0.02 W/(m K), specific surface area on the order of 65 m(2)/g, and loose bulk density in the range 0.02-0.04 g/cm(3)) by hydrothermal treatment of gamma-Al(2)O(3)nanopowder in a 1.5% HCl solution at 200 degrees C. The steps of the process have been identified and it has been shown to be a solid-state (topochemical) transformation.