Crystallization of CaCO₃ induced by mixed template of polymer and surfactant

Calcium carbonate was prepared by the Na₂CO₃ with CaCl₂ in the mixed templates of polymer(PVA/PSSS) and surfactant(CTAB) at different temperatures and concentrations of CTAB. The products were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD). The results showed that in the PVA/CTAB system the ellipsoid aggregates of calcite could be prepared at 5°C and rosette type and cubic aggregates of calcite and vaterite at 25°C while druses of needle-like aragonite crystals were obtained at 90°C. In the PSSS/CTAB system, spherical precipitation of calcite and vaterite could be obtained at 5°C, uniform size of spherical vaterite were obtained at 25°C. At the temperature of 90°C, flower-like aragonite was precipitated. The different complex of polymer and CTAB resulted in the different morphology and crystal form of calcium carbonate.