The influence of O-carboxymethylchitosan on the crystallization of calcium carbonate

Abstract Calcium carbonate (CaCO 3 ) was crystallized in the presence of O -carboxymethylchitosan (CMCS) by a vapor diffusion method. The CaCO 3 particles were characterized by scanning electron microscopy (SEM), the energy dispersion spectroscopies (EDS), powder X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetry analysis (TGA) and N 2 adsorption–desorption methods. By varying the concentrations of CMCS, Ca 2+ and Mg 2+ ions, and temperature, the CaCO 3 nanocrystals with different morphologies were produced. Based on the analysis of CaCO 3 particles obtained under different conditions, the mechanism of the CaCO 3 crystallization in the presence of CMCS was proposed.