Effect of initial pH on formation of hollow calcium carbonate particles by continuous CO2 gas bubbling into CaCl2 aqueous solution

Hollow calcium carbonate (CaCO3) particles are synthesized by continuous bubbling CO2 gas into CaCl2 aqueous solution. In order to study the formation kinetics of the hollow CaCO3 particles, the transmitted light strength of the CaCl2 solution during the reaction was measured automatically with an on-line monitoring. It was verified that the pH for the formation of the hollow particles depended on the reaction temperature. Higher initial pH of the CaCl2 solution resulted in the higher ratio of hollow particles as compared to that obtained at lower pH.