GROWTH OF CRYSTALS IN SOLUTION

The crystallization of sparingly soluble salts from their aqueous supersaturated solutions is discussed from the standpoint of two important applications; scale formation and biological mineralization. Theories of crystal growth are outlined and the importance of kinetic factors in determining the nature of the growing phases is discussed. The kinetic factors can be studied by using a highly reproducible seeded growth technique and under certain conditions secondary nucleation can also be induced on the surface of the inoculating seed crystals. The kinetics of crystallization of the alkaline earth surfaces and the calcium phosphates is discussed. In the latter systems, temperature, supersaturation, surface concentration, pH, ionic strength and the presence of foreign ions are important in determining the nature of the phase which grows on the added seed crystals. The mechanism of the retardation of crystal growth by added crystallization inhibitors is illustrated by the influence of organic phosphonate molecules upon the precipitation of calcium carbonate. © 1979.