Formation and breakage of chain-like in preparation of nano-sized precipitated calcium carbonate

Nano-precipitated calcium carbonate (NPCC) exhibits multiple morphologies and unique properties to satisfy various requirements in industry. In this study, monodisperse and cubic NPCC were prepared by a solution mixing method using NaOH, Na2CO3, and CaCl2 as raw materials. The morphology of CaCO3 was controlled by the amount of NaOH in the precipitation process. X-ray diffraction (XRD), and scanning electron microscope (SEM) were employed for characterizations of CaCO3. The formation and the subsequent fission of nanofibril-like CaCO3 played an important role in the stages of NPCC preparation. The effects of pH, Ca2+, and Mg2+ concentration on the fission process were studied. The results indicate that the low pH, low Ca2+, and Mg2+ ions concentrations are beneficial to the fission of nanofibril-like CaCO3, and the correlation mechanism is proposed.