Transferencia de masa y criterios de cristalización en el crecimiento en geles de cristales de estroncianita

Abstract

Supersaturation is not enough to interpret nucleation phenomena in crystal growth in gels. The explanation of the first precipitate location needs complementary crystallization criteria. The experimental testing of both, mass-transfer and pH evolution, is the background to establish rigorous hypothesis. From these data, the actual distribution of free ions, ionic associations and supersaturation throughout the gel column may be known. In the case of nucleation and growth of strontianite crystals, the experimental results show that a complementary hypothesis isneccesary: the “equality range” of the reagent’s concentration. The significance of both, the concentration influence in the reagent’s diffusivity and the pH evolution, is also experimentally shown. Nucleation density and growth mechanisms are finally explained in base to supersaturation velocity and kinetics roughness.