Crystallization of aragonite CaCO3 with complex structures

In this work, aragonite CaCO3 with complex morphologies was synthesized through homogeneous precipitation, in which calcium acetate and urea precipitated at 90 degrees C in the presence of PVP. The effect of the concentration of urea and PVP on the CaCO3 crystalline was investigated. The morphology and structure of the CaCO3 particles were characterized by SEM, XRD, and FT-IR. It was found that the concentrations of urea and PVP in the mixed aqueous solution were turned out to be important parameters for the morphology of CaCO3 particles. All CaCO3 particles were mainly aragonite with morphology from bundles of rods, bouquet-like and dumbbell-like. And there was no phase transition under the research conditions. Moreover, the possible process for the formation of the morphology of aragonite was discussed. (C) 2010 The Society of Powder Technology Japan. Published by Elsevier BM. and The Society of Powder Technology Japan. All rights reserved.