Abstract:

A common route  to  form biogenic minerals during biomineralization  is  that  the  initial deposit of  transient amorphous
precursor phases and subsequent transformation into one of more stable crystalline phases. In terms of biogenic calcium carbonate
minerals, amorphous precursor phase is generally considered to be formed under the joint regulation of biological macromolecules
and  inorganic  ions.  In  this work, amorphous calcium carbonate  (ACC) was synthesized  in  the presence of citrate anions by a
biomimetic mineralization process. Structure and morphology of the synthesized ACC and the subsequently products from the ACC
transformed were characterized using a wide range of techniques, including field emission scanning electron microscopy (FESEM),
X-ray diffraction (XRD), Fourier infrared spectroscopy (IR) and thermal gravity analysis-differential thermal analysis (TG-DTA).
The results showed that the multi-carbonate anions could induce the formation of ACC which had a similar composition to biogenic
hydrous ACC. Therefore, our results suggest that some biomineralization-associated acidic biomacromolecules canalso induce the
formation of biogenic ACC and transiently stabilize it.

Key words:  amorphous calcium carbonate (ACC), sodium citrate, calcite, biomimetic mineralization, biomineralization