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Crystallization kinetics of amorphous calcium carbonate in confinement.

ABSTRACT: Phase transformations of carbonates are relevant to a wide range of biological, environmental, and industrial processes. Over the past decade, it emerged that crystallization pathways in these systems can be quite complex. Metastable intermediates such as amorphous calcium carbonate (ACC) were found to greatly impact composition, structure, and properties of more stable phases. However, it has been challenging to create predictive models. Rapid transformation of ACC in bulk has been one obstacle in the determination of nucleation rates. Herein, it is reported that confinement in microfluidic droplets allows separating in time the precipitation of ACC and subsequent nucleation and growth of crystalline CaCO₃. An upper limit of 1.2 cm^-3 s^-1 was determined for the steady-state crystal nucleation rate in the presence of ACC at ambient conditions. This rate has implications for the formation of calcium carbonate in biomineralization, bio-inspired syntheses, and carbon sequestration.

SUBMITTER: Cavanaugh J

PROVIDER: S-EPMC6530533 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature

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Crystallization kinetics of amorphous calcium carbonate in confinement.

Cavanaugh Jack J Whittaker Michael L ML Joester Derk D

Chemical science 20190411 19

Phase transformations of carbonates are relevant to a wide range of biological, environmental, and industrial processes. Over the past decade, it emerged that crystallization pathways in these systems can be quite complex. Metastable intermediates such as amorphous calcium carbonate (ACC) were found to greatly impact composition, structure, and properties of more stable phases. However, it has been challenging to create predictive models. Rapid transformation of ACC in bulk has been one obstacle ...[more]

PMID: 31183054

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