NANO-POROUS SUPERFINE POWDERS MADE FROM ALPHA ALUMINUM OXIDE AND METHOD OF PREPARATION OF SUCH POWDERS BY SUBLIMATION DRYING

摘要

FIELD: production of nano-porous powders from alpha aluminum oxide used for polishing. ^ SUBSTANCE: proposed nano-porous powder contains primary particles of alpha aluminum oxide at average diameter lesser than 10 nm and inter-permeable net of pores or voids. Proposed powder is prepared by method including the following operations: use of inorganic sol containing at least one precursor of aluminum oxide and many seeding particles of alpha aluminum oxide; addition of at least one water-soluble organic polymer to inorganic sol for obtaining organic-inorganic sol; sublimation drying of organic-inorganic sol for obtaining solid gel and firing of solid gel. Nano-porous powder is made at additional grinding of powder from alpha aluminum oxide after firing. Suspension containing the powder of nano-size is used for polishing the base by applying the suspension on interface between base and polisher. ^ EFFECT: high purity of fine homogeneous powders. ^ 71 cl, 3 dwg, 2 ex