| Abstract: | Abstract To prepare fine powders of oxides, supercritical fluid drying was applied. As the case of point, Y–Ba–Cu complex oxide was taken up. A suspension of Y–Ba–Cu complex oxide was synthesized by simultaneous hydrolyzation of 2-propanol solution of yttrium triisopropoxide–barium diisopropoxide–copper diisopropoxide. The supercritical fluid drying by carbon dioxide was confirmed to dry the suspensions, expecting no aggregation of particles throughout the drying procedure. First of all, solubilities of 2-propanol, water, and aqueous 2-propanol solution in high pressure carbon dioxide were measured. Judging from the observed solubilities, temperatures, and pressures in drying conditions were determined. The drying rates were measured and the dried powders were characterized by DTA, TGA, and SEM. The results of these experiments suggested that the supercritical fluid drying process is useful for drying of the suspensions of superconducting compound prepared by hydrolyzation of alkoxides. |
