Mechanism of unusual polymorph transformations in calcium carbonate: Dissolution-recrystallization vs additive-mediated nucleation

Abstract

Unusual transformation of one CaCO3 phase to another has been reported by the process of dissolution-recrystallization and under the influence of additive. In one case, while metastable vaterite transforms to another metastable phase aragonite by simple refluxing in distilled water, it instead transforms thermodynamically stable phase calcite upon refluxing in its 'mother-liquor'. This is explained by the process of dissolution- recrystallization. In another case, aragonite is preferentially synthesized over calcite in the presence of molten lauric acid as an additive. © 2012 Indian Academy of Sciences.