CaCO3 crystallization controlled by (2-hydroxypropyl-3-butoxy) propylsuccinyl chitosan

Calcium carbonate (CaCO3) was crystallized in (2-hydroxypropyl-3-butoxy) propyl-succinyl chitosan (HBP-SCCHS) solutions by a slow vapor diffusion method. The CaCO3 crystals were characterized by scanning electron microscopy (SEM), powder X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetry analysis (TGA) and N2 adsorption–desorption methods. By varying the concentrations of HBP-SCCHS and Ca2+, temperature and initial pH, the CaCO3 crystals with different morphologies were obtained. Based on the analysis of CaCO3 crystals obtained under different conditions, the mechanisms of the CaCO3 crystallization in the presence of HBP-SCCHS were proposed. It was found that the adsorption of HBP-SCCHS molecules on CaCO3 surfaces played a key role in the formation of CaCO3.

Graphical abstractTypical SEM images of CaCO3 particles obtained from HBP-SCCHS solution. The inset is the magnified SEM image of lenticular-like aggregates after being calcined at 400 °C for 12 h.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► CaCO3 was crystallized in HBP-SCCHS solutions by a slow vapor diffusion method. ► Several influencing factors on the crystallization were investigated. ► The mechanisms of the CaCO3 crystallization in HBP-SCCHS solutions were proposed. ► The work will provide good insight into the CaCO3 crystallization.