Hollow calcium carbonate microspheres prepared in the presence of polyoxyethylene (20) sorbitan monolaurate and sodium dodecyl sulfate

Hollow calcium carbonate (CaCO₃) microspheres were prepared in aqueous solution with the presence of polyoxyethylene (20) sorbitan monolaurate (Tween20) and sodium dodecyl sulfate (SDS). The microspheres were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscope (TEM). The X-ray diffraction data showed that the hollow CaCO₃ microsphere consisted of calcite crystals. The influence of Tween20 and SDS concentrations on the morphology of CaCO₃ crystals was investigated. The results suggested that the"core-shell model"of Tween20/SDS micelle aggregated as templates, which could control the growth of hollow CaCO₃ microspheres. The interaction between mixed surfactants and calcium ions played a critical role in organizing calcium carbonate in microscopic level.