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

doi:10.3390/nano12234151

The Kinetics of Aragonite Formation from Solution via Amorphous Calcium Carbonate

Nanomaterials (Basel). 2022 Nov 23;12(23):4151. doi: 10.3390/nano12234151.

Authors

Simon M Clark^{1

2}, Vili Grigorova¹, Bruno Colas^{1

2}, Tamim A Darwish³, Kathleen Wood², Joerg Neuefeind⁴, Dorrit E Jacob⁵

Affiliations

¹ School of Engineering, Faculty of Science and Engineering, Macquarie University, North Macquarie Park, Shellharbour, NSW 2109, Australia.
² Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, Sydney, NSW 2232, Australia.
³ National Deuteration Facility, Australian Nuclear Science and Technology Organisation, Kirrawee DC, Sydney, NSW 2232, Australia.
⁴ Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
⁵ Research School of Earth Sciences, The Australian National University, Canberra, ACT 2600, Australia.

Abstract

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.

Keywords: ACC; Laser-Ablation Inductively Coupled Plasma Mass Spectrometry; Mg/Ca; NOMAD; QUOKKA; Small Angle Neutron Scattering; X-ray diffraction; aragonite; neutron scattering; themo gravimetric analysis.

Abstract

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