Biomineralization II / Topics in Current Chemistry Bd.271 (PDF)

Delayed Action of Synthetic Polymers for Controlled Mineralization of Calcium Carbonate (p. 119-120)

Abstract Natural inorganic–organic hybrid materials are formed through mineralization of inorganic materials on self-assembled organic materials. In these mineralized tissues, crystal morphology, size, and orientation are determined by local conditions and, in particular, the presence of "matrix" proteins or other macromolecules. The final crystalline phase arises through a series of steps initiated by the formation of an amorphous phase that undergoes subsequent phase transformations. The multi-step crystallization process on living systems was supported by the detection of different mineral polymorphs in natural organisms and subsequent phase transformation. This work focuses on a new concept for controlling crystal polymorphs by delayed action of organic additives during nucleation stages. During the formation of continuous thin films of minerals, several authors have used a phase-transformation process from an initially deposited amorphous phase to crystalline phase. The delay addition method gives a new simple process for controlling the CaCO3 crystallization. Three different crystal polymorphs of CaCO3 (aragonite, vaterite, and calcite) were selectively induced by changing the time when the radical initiator was added to a calcium carbonate solution with sodium acrylate. These processes may be similar to the secretion of specific proteins or molecules during the transformation of biomineralization.

Keywords Calcium carbonate · Delay addition · In situ polymerization · Latent inductor · Transformation

Abbreviations
ACC amorphous calcium carbonate
DMSO dimethyl sulfoxide
FT-IR Fourier transform infrared spectroscopy
h hour(s)
KPS potassium peroxodisulfate
L liter(s)
min minute(s)
mol mole(s)
Mw weight average molecular weight
PAA poly(acrylic acid)
PAZO polyazobenzen
PVP