Nanosized corundum synthesis

Alumina continues to play an important role in the materials industry with the Payer process still providing alumina after a 100 years of continuous processing. In addition to traditional applications of alumina, alumina is being advanced as a major part of the new frontier on nanophase materials and nanophase technology. High surface area corundum has been synthesized using a rapid totally "green" hydrothermal process for forming nanosized diaspore precursor to nanosized corundum. Surface areas of the nanosized corundum are in excess of 160 square meters per gram. High temperature solution calorimetry show that gamma alumina becomes the energetically stable phase relative to corundum at specific surface areas greater than 125 square meters per gram. These data provide a thermodynamic basis for the equilibrium relationships among the alumina phases in the nanocrystalline region.