SUPERSATURATION AND CRYSTAL-GROWTH IN GAS ANTI-SOLVENT CRYSTALLIZATION

A technique of developing a low expansion rate of solution under const ant temperature was employed to examine the saturation behavior of exp anded solutions and the growth of crystals in the gas anti-solvent cry stallization. When solutions were expanded under pressure, three types of saturation behavior were observed. The behaviors are explicable us ing an chi factor. The growth phenomenon, growth rate, and growth mech anism of crystals in the GAS process were similar to those usually fou nd in the conventional processes of solution crystallization except th at millimeter-sized inorganic crystals without well-defined faces cann ot re-facet themselves. (C) 1998 Elsevier Science B.V. All rights rese rved.