The Kinetics of Aragonite Formation from Solution via Amorphous Calcium Carbonate
Simon M. Clark,
Vili Grigorova,
Bruno Colas,
Tamim A. Darwish,
Kathleen Wood,
Joerg Neuefeind,
Dorrit E. Jacob
Affiliations
Simon M. Clark
School of Engineering, Faculty of Science and Engineering, Macquarie University, North Macquarie Park, Shellharbour, NSW 2109, Australia
Vili Grigorova
School of Engineering, Faculty of Science and Engineering, Macquarie University, North Macquarie Park, Shellharbour, NSW 2109, Australia
Bruno Colas
School of Engineering, Faculty of Science and Engineering, Macquarie University, North Macquarie Park, Shellharbour, NSW 2109, Australia
Tamim A. Darwish
National Deuteration Facility, Australian Nuclear Science and Technology Organisation, Kirrawee DC, Sydney, NSW 2232, Australia
Kathleen Wood
Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, Sydney, NSW 2232, Australia
Joerg Neuefeind
Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
Dorrit E. Jacob
Research School of Earth Sciences, The Australian National University, Canberra, ACT 2600, Australia
Magnesium doped Amorphous Calcium Carbonate was synthesised from precursor solutions containing varying amounts of calcium, magnesium, H2O and D2O. The Mg/Ca ratio in the resultant Amorphous Calcium Carbonate was found to vary linearly with the Mg/Ca ratio in the precursor solution. All samples crystallised as aragonite. No Mg was found in the final aragonite crystals. Changes in the Mg to Ca ratio were found to only marginally effect nucleation rates but strongly effect crystal growth rates. These results are consistent with a dissolution-reprecipitation model for aragonite formation via an Amorphous Calcium Carbonate intermediate.
