The Surface Acidities of the Compressed Calcium Sulfate and Cadmium Sulfate

Abstract

In order to clarify the mechanism of the acidity change due to compression, the surface acidities and the structures of calcium and cadmium sulfates compressed under various pressures were studied; for CaSO₄ the pressure was 0-3840 kg/cm² at 20, 65, or 85° C, and for CdSO₄ the pressure range 0-7000 kg/cm² at 50° C. It was observed that the surface acidities of both solids vary on compression. From the results of the powder X-ray diffraction, the DTA, and the infrared absorption studies, the relation between the acidity and the structural changes was discussed.