Preparation and crystallization of amorphous calcium carbonate in solution

Calcium carbonate (CaCO3) is one of the most abundant minerals. It precipitates from aqueous solution enabling three anhydrous polymorphs (calcite, aragonite, and vaterite), two hydrated forms (hex hydrate ikaite and monohydrate) and an amorphous phase. The non-crystalline forms of calcium carbonate are known as amorphous calcium carbonates (ACCs). Studies of ACCs show that ACCs play a crucial role as transient precursors to formation of calcite or aragonite (a crystalline forms of CaCO3) [1,2]. The distribution of ACCs in biological systems as well as the role they play in calcium carbonate bio mineralization must not be underestimated. The synthesis of inorganic-organic layers by bio mineralization methods has become interest to scientists and researchers. In this work we have experienced solutions of amorphous calcium carbonates and Polyethylene glycol (PEG). Many parameters intervene in the precipitation of the calcium carbonate crystal which is reviewed in order to optimize of effective parameters required for specific types of product. Variables that affect the precipitation process have been experimented such as time and concentration. In this work, microscopic and spectroscopic figures have been obtained from control and sample. The main changes are regarding as particle sizes and cubic morphology of particles .It seems that time has more influence on the change of morphology.

Keywords:

Amorphous calcium carbonate (ACC) , Crystallization , Polyethylene glycol (PEG) , Spectroscopy