Formation and Aging of Precipitates. III. Electron Microscopic Studies on Barium Sulfate Precipitates in Aqueous Alcohol

Abstract

Abstract 1. The solubilities of barium sulfate in aqueous alcohol were measured. 2. The barium sulfate particles precipitated in aqueous alcohol became smaller with the increasing concentration of alcohol; namely, with the decreasing solubility of barium sulfate. 3. In the case of the aqueous alcohol of the certain percentage (for a definite solubility of barium sulfate) the precipitated particles became larger with the decreasing total concentration of barium sulfate. 4. The barium sulfate precipitates prepared in the aqueous alcohol were practically diamond shaped; and spindle, hexagonal and sphere particles were also found. The shape of the precipitated particles seemed to depend on the induced period of the precipitation. 5. The electron micro-diffraction method was applied to analyze the crystal structure and, of course, the patterns obtained from various types of crystals agreed with those of barium sulfate.