Patent ID: 8080231

Claim:
A process for the production of nanoporous α-alumina powders which comprises the steps of providing an inorganic sol comprising at least one alumina precursor and a plurality of α-alumina seed particles; adding at least one water soluble organic polymer to the inorganic sol to form an organic-inorganic sol; freeze drying the organic-inorganic sol to form a solid gel; and firing the solid gel at a temperature capable of combusting the organic polymer and inducing α-alumina formation of a nanoporous α-alumina powder comprising interconnected α-alumina primary particles having an average particle size of less than about 100 nm and a plurality of voids, wherein the α-alumina primary particles comprise between about 10-50 vol % of the nanoporous α-alumina powders, the volume of the nanoporous α-alumina powders being the total volume of α-alumina primary particles and the volume of void space.