Controlled deposition and transformation of amorphous calcium carbonate thin films

Controlled synthesis of amorphous calcium carbonate (ACC) films was realized by using the multiple templates, which are composed of a self-assembled film (SAF, insoluble Poly (F-caprolactone) film) and a soluble modifier (poly allylamine), as modifiers. The formation of self-assembled film was analyzed by monitoring the morphologies using atomic force microscopy. Even more noteworthy, using anhydrous ethanol as media, the ACC-to-vaterite-to-calcite transformation was also investigated, and the obtained products were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. The results demonstrated that organic solvent has profound influence on transformation of amorphous calcium carbonate thin films. In the air of anhydrous ethanol, the controlled synthesis of calcium carbonate films with different morphologies, such as planar films with a few sporadic particles, symmetric rhombohedral crystals, novel crystals with symmetrical terraced convexity formation of calcite, was obtained by the fine-tuning of induction time. It provides a new and simple method to prepare polymorphic CaCO3 crystal films from the ACC films by controlling the crystallization process (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim