Effect of Convection on Crystal Growth of Calcium Phosphate in a Thermostat under Terrestrial and Space Conditions

Abstract

Mass transfer in the process of crystal growth of octacalcium phosphate Ca8H2(PO4)6 and hydroxyapatite Ca10(OH)2(PO4)6 during mixing aqueous solutions of CaCl2 and KH2PO4 + K2HPO4 in a buffer solution KCl is simulated mathematically with regard to the stoichiometric relationship. The investigations are carried out for the weightlessness, microgravity, and normal gravity conditions. The effect of gravity (convection) on the nature of reaction component transfer in the process of crystal growth of calcium phosphate under the temperature–controlled conditions is considered. It is shown that the reaction component transfer times are less under convection mixing as compared with the purely diffusive regime, but the rate and mass of formation of calcium phosphate depend not only on the convection time and intensity but also on the convection mixing structure.