PROBING THE DYNAMICS OF TEMPLATE-DIRECTED CALCITE CRYSTALLIZATION WITH IN-SITU FTIR

Organic template-directed mineralization of calcite crystals has been probed in situ by external reflection-absorption FTIR spectroscopy in an effort to understand the dynamics of the organic-inorganic interfac e during crystal growth. The main focus is to elucidate structural cha nges that may occur in the organic template as crystal growth progress es. The nucleation face types of calcite were visually identified acco rding to known crystal morphologies and by the corresponding carbonate stretching and deformation vibrational bands. Structural reorganizati on occurring in the organic template could be observed by intensity va riations and frequency shifts in the methylene stretching bands of oct adecanoic acid, octadecyl sulfate, and acidic polydiacetylenic lipid f ilm, These organic templates nucleated calcite at the (010), (001), an d (012) planes, respectively. The surfactant thin films uniquely adapt themselves in order to optimize the geometrical and stereochemical fi t to the growing calcite crystals.