Macro- to nanoscale study of the effect of aqueous sulphate on calcite growth

摘要

Calcite growth rates were measured in the presence of sulphate using mixed-flow reactors and in situ Atomic Force Microscopy. Preliminary observations reveal that the kinetics and mechanism of the calcite growth was altered by the presence of sulphate. Calcite growth rates in the presence of sulphate (>= 5 mM) were decreased and two-dimensional nuclei tend to grow on top of existing nuclei, rather than spreading. The height of new nuclei was approx 4 A, 1 A greater than that of pure calcite growth. This difference reflects the incorporation of tetrahedral SO_4~(2-) anions into the calcite lattice.