Crystallization kinetics of amorphous calcium carbonate in confinement† †Electronic supplementary information (ESI) available: Materials and methods and supplemental figures, movies and discussion. See DOI: 10.1039/c8sc05634j
| Autor: | Cavanaugh, Jack, Whittaker, Michael L., Joester, Derk |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: | |
| Zdroj: | Chemical Science |
| ISSN: | 2041-6539 2041-6520 |
| Popis: | In situ observation of amorphous calcium carbonate (ACC) confined in ∼500 pL emulsion droplets allows determination of the timing of individual crystal nucleation events. Statistical analysis of events in hundreds of droplets establishes an upper limit for the steady-state nucleation rate of 1.2 cm–3 s–1 for the crystallization from ACC. 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. |
| Databáze: | OpenAIRE |
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