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Monodisperse Calcium Carbonate Microtablets Forming at 70°C in Prerefrigerated CaCl 2 –Gelatin–Urea Solutions
Author(s) -
Tas A. Cuneyt
Publication year - 2009
Publication title -
international journal of applied ceramic technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 57
eISSN - 1744-7402
pISSN - 1546-542X
DOI - 10.1111/j.1744-7402.2008.02252.x
Subject(s) - gelatin , vaterite , calcium carbonate , calcite , urea , materials science , dispersity , aqueous solution , chemical engineering , particle size , scanning electron microscope , fourier transform infrared spectroscopy , thermal decomposition , particle (ecology) , nuclear chemistry , mineralogy , polymer chemistry , chemistry , composite material , organic chemistry , aragonite , oceanography , geology , engineering
Calcium carbonate particles with a unique tablet shape were produced by simply aging the prerefrigerated (at 4°C for 24 h) CaCl 2 –gelatin–urea solutions at 70°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 Ca 2+ ion and gelatin‐containing solutions with aqueous carbonate ions. Monodisperse CaCO 3 microtablets formed in solution had a mean particle size of 4±2.5 μm. CaCO 3 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°C for 24 h. Prerefrigeration of CaCl 2 –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.