Synthesis of hollow calcium carbonate particles by the bubble templating method

Hollow calcium carbonate (CaCO3) is a potential component in many industrial fields such as plastics, rubbers, papermaking, and drug delivery. This paper described a novel approach to synthesize hollow CaCO3 particles by using bubble as template via passing CO2 bubbles into calcium chloride (CaCl2) solution in the presence of ammonia (NH3) at 27 °C. The CO2 bubble is not only the reactive material, but also the template of hollow particles. The newly-formed primary particles attach to bubbles and form a solid shell. After filtering and drying the hollow CaCO3 particles were obtained. Physical characteristics of the precipitate were evaluated using scanning electron microscopy (SEM) and X-ray diffraction (XRD).