Influence of ionic surfactants on the properties of freshly precipitated calcium carbonate

Properties of calcium carbonate precipitated from aqueous solutions of CaCl2 and Na2CO3 in the presence of 10−2 M sodium dodecyl sulfate (SDS) or dodecyltrimethylamonium bromide (DDTAB) were studied. It was found that the presence of SDS inhibited transformation of vaterite to calcite. However, when the cationic surfactant was used more calcite crystals of smaller size appeared in comparison to the reference system. The added surfactants changed also the kinetics of CaCO3 precipitation. While DDTAB probably adsorbed electrostatically to the negatively charged calcium carbonate surface, the mechanism of SDS/CaCO3 interaction is not clear and required more investigation.