Monodisperse Calcium Carbonate Microtablets Forming at 70 degrees C in Prerefrigerated CaCl2-Gelatin-Urea Solutions
| Autor: | Tas, AC |
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| Přispěvatelé: | Tas, AC, Yeditepe Üniversitesi |
| Jazyk: | angličtina |
| Rok vydání: | 2009 |
| Popis: | Calcium carbonate particles with a unique tablet shape were produced by simply aging the prerefrigerated (at 4 degrees C for 24 h) CaCl2-gelatin-urea solutions at 70 degrees C for 24 h in ordinary glass media bottles. Gelatin is known to be the denatured collagen. The thermal decomposition of dissolved urea was exploited to provide the Ca2+ ion and gelatin-containing solutions with aqueous carbonate ions. Monodisperse CaCO3 microtablets formed in solution had a mean particle size of 4 +/- 2.5 mu m. CaCO3 microtablets were biphasic in nature and comprised of about 93% vaterite and 7% calcite. Identical solutions used without prerefrigeration yielded only trigonal prismatic calcite crystals upon aging at 70 degrees C for 24 h. Prerefrigeration of CaCl2-gelatin-urea solutions was thus shown to have a remarkable effect on the particle morphology. Samples were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, and powder X-ray diffraction. |
| Databáze: | OpenAIRE |
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