No abstract

No abstract

No abstract

Calcium carbonate (CaCO 3 ) is widely used as an important model system for investigating inorganic precipitation reaction or crystallization. However, recent results show that the yield of vaterite CaCO 3 microspheres is poor in ethanol/water in the presence of polyelectrolyte poly(sodium 4-styrenesulfate) (PSS), which is up to 16 mM. We now report on an approach to synthesize pure vaterite CaCO 3 microspheres through improving the concentration of polymer PSS and the yield is greatly high up to 80 mM. The exploration provides the possibility for large-scale synthesis of CaCO 3 materials with controllable morphology and crystallographic structure in aqueous solution at room temperature. The possible formation mechanism toward the occurrence of vaterite CaCO 3 microspheres has also been illustrated in virtue of a series of time-resolved experimental results. It is revealed that the vaterite microspheres evolve gradually from the initial amorphous precursor, to poorly crystallized nanoparticles, to sphere-like aggregates, and then to vaterite microspheres embedded with the calcite rhombohedra, finally to the vaterite microspheres with smooth surface. This research may provide a new viewpoint into the forming process of vaterite CaCO 3 microspheres.

No abstract