Effects of organic additives on the morphology of calcium carbonate particles in the presence of CTAB

In this paper, calcium carbonate particles with unusual morphologies could be easily obtained by a precipitation reaction of sodium carbonate with calcium chloride from mixed solution of organic solvents and water in the presence of cetyltrimethylammonium bromide (CTAB) at 80 degrees C. The as-prepared products were characterized with scanning electron microscopy and X-ray diffraction. The effects of different organic additives-glycol, glycerine, formaldehyde, acetaldehyde, glycol-methyl ether and glycol-ethylether, on the crystal form and morphology of the as-prepared CaCO3-were investigated and discussed. The results show that organic additives can have great influence on the forms and morphologies of CaCO3 at relative high temperature in the presence of CTAB. Various unusual crystal morphologies, such as dendrite-shaped, flower-like, wheatgrass-like, needle-like, whiskers, double-taper-like, etc., can be obtained depending on the experimental conditions. In particular, pure aragonite with unusual morphologies can be produced in the presence of glycol, glycerine, glycol-methyl ether at 80 degrees C, krespectively. (c) 2005 Elsevier B.V. All rights reserved.