Supercritical Fluid Technologies for Ceramic-Processing Applications

The applications of supercritical fluid technologies for ceamic processing are reviewed. The novel physical and chemical properties of these densified gases are summarized and related to their use as solvents and processes benefit from the unique properties of supercritical fluids. The rapid expansion of supercritical fluid solutions provides a technique for producing fine uniform powders and thin films of widely varying materials. Supercritical drying technologies allow the formation of highly porous aerogel products with potentially wide application. Hydrothermal processes leading to the formation of large single crystals and microcrystalline powders can also be extended into the supercritical regime of water. Additional applications and potential applications are identified in the areas of extraction of binders and other additives from ceramic compacts, densification of porous ceramics, the formation of powders in supercritical microemulsions, and in preceramic polymer processing.