Effect of Doping with Sodium and Potassium on the Phase Formation in the Synthesis of Calcium Sulfate

Abstract

Materials based on calcium sulfate in which Na⁺ or K⁺ cations were substituted to a concentration of 5, 10, or 20 mol % for Ca²⁺ cations were synthesized and studied. The introduction of Na⁺ produced materials with the structure of calcium sulfate hemihydrate and dihydrate, and the incorporation of potassium yielded a mixture of calcium sulfates with various contents of chemically bound water and sulfates in which potassium cations formed compounds with different Ca : K ratios. The doping of calcium sulfate with sodium and potassium cations increased the solubility of materials by a factor of 1‒2 and 3‒4, respectively. The developed materials are promising in medical applications for filling bone tissue defects and also for using as a cement matrix for targeted drug delivery.