Gram-scale synthesis and shape evolution of micro-CaCO3

A facile solution precipitation route (between Ca2+ and CO32−) for the gram-scale synthesis of uniform micro-CaCO3 from cubes, to spheres, to ellipses, to oblates, and to rods via control of the type and amount of oriented additives (dodecyl sodium sulfate, cetyltrimethylammonium bromide, Ba2+ and Co2+) has been demonstrated. The products were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). In the presence of Ba2+, dispersed micro-CaCO3 spheres (average diameter is 2391.1 nm, the majority particles are distributed in the range of 1574.1 to 4068.2 nm) could be vastly obtained in a highly morphological yield (~ 100%). The formation process of these microstructures was clarified as the synergic effect of oriented arrangement and ripening mechanism with face-selective additives adsorption on the growing CaCO3 particles.