Results 181 to 190 of about 8,605 (221)

Oriented Crystallization of Vaterite in Collagenous Matrices

Chemistry - A European Journal, 1998
The influence of high super- saturation on kinetic control and the importance of the polypeptide structure in the crystallization of calcium carbo- nate polymorphs were studied in cross- linked gelatin films containing high concentrations of the polypeptides poly-l-aspartate and poly-l-glutamate.
Falini G, Fermani S, Gazzano M, Ripamonti, A   +4 more
openaire   +3 more sources

Raman Spectra of Vateritic Calcium Carbonate

Spectroscopy Letters, 1995
Abstract The Raman spectrum of polycrystalline vaterite is presented and compared to spectra of calcite and aragonite, the other two common CaCO3 polymorphs; Raman spectroscopy easily distinguishes between these three polymorphs. An important feature of the Raman spectrum of vaterite is splitting of both the ν1 and ν4 peaks.
Gesa Behrens, Liisa T. Kuhn, Rick Ubic, Arthur H. Heuer   +3 more
openaire   +1 more source

Sonosynthesis of Vaterite-Type Calcium Carbonate

Crystal Growth & Design, 2017
Metastable nanoparticles of vaterite were formed using a simple ultrasound technique. The effects of ultrasound amplitude and duration, as well as solution concentration, were investigated. The produced particles were characterized using standard X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning and transmission ...
Judith A. Juhasz-Bortuzzo, Barbara Myszka, Raquel Silva, Aldo R. Boccaccini   +3 more
openaire   +1 more source

Thermal transformations of vaterite and calcite

Thermochimica Acta, 1994
Abstract The polymorphic transition and the thermal decomposition of vaterite are characterized. The effect of the morphology of the parent vaterite upon the polymorphic transition as well as upon the decomposition of pseudomorphous ex-vaterite, i.e. “spherulitic” calcite, is presented.
Maciejewski, Marek, Oswald, Hans-Rudolf, Reller, Armin   +2 more
openaire   +1 more source

The crystallization of vaterite on cholesterol

Journal of Colloid and Interface Science, 1989
In gallstones the occurrence of stones of cholesterol with calcite and vaterite has been observed. Cholesterol is a crystalline, water-insoluble matrix, with favorable lattice matching with both calcite and vaterite. In the present work it was shown that cholesterol can nucleate vaterite on its surface following well-defined induction periods. Kinetics
Evangelos Dalas, Petros G Koutsoukos
openaire   +1 more source

Morphosynthesis of Calcium Carbonate (Vaterite) Microsponges

Advanced Materials, 1999
Dominic Walsh, Stephen Mann
exaly   +2 more sources

Dopamine-Induced Mineralization of Calcium Carbonate Vaterite Microspheres

Langmuir, 2010
Two biogenic materials from mussels are attracting attention from scientists: calcium carbonate (CaCO(3)), the most widely studied biomineral that composes the shell, or nacre, of mussels, and dopamine, a small catechol-containing biomimetic molecule of adhesive foot proteins secreted by mussels.
Kim, S Kim, Sungjin, Park, CB Park, Chan Beum   +1 more
openaire   +3 more sources

A thermochemical study of vaterite

Geochimica et Cosmochimica Acta, 1973
Abstract Vaterite is shown to be unstable with respect to calcite at 25°C by measurements of the enthalpies of solution in 0·1 N HCl under 0·97 atm CO 2 and the solubilities in water under 0·97 atm CO 2 of the two polymorphs. For a pure, synthetic vaterite ΔH ( tr ) = −1036 ±16 cal mol −1 and ΔG ( tr ) = −790 ± 25 cal mol −1 for the transition
openaire   +1 more source

The crystallization of vaterite on fibrin

Journal of Crystal Growth, 2000
Abstract Fibrin, a protein endoproduct of blood coagulation was found to be a substrate favoring the deposition of vaterite crystals from stable supersaturated solutions at pH 8.5 and at 25°C. The apparent order for the vaterite crystallization reaction was found to be 1.0±0.1, suggesting a surface diffusion-controlled mechanism.
J Kanakis, E Dalas
openaire   +1 more source

Precipitation of Vaterite in Lake Water

Nature Physical Science, 1971
VATERITE is a microcrystalline form of calcium carbonate. It is rarely observed in nature, but has now been identified in a precipitate formed in Holkham Lake, Norfolk. The lake is nearly one mile long, is fed by springs at the south end and discharges over a weir towards the sea at the north. At the south end a narrow stretch, about 200 yards long, is
D. L. G. ROWLANDS, R. K. WEBSTER
openaire   +1 more source