The precipitation of carbonate minerals is widely studied due to its importance in marine and sedimentary environments, industrial processes, and geoengineering (e,g., geologic CO2 sequestration). However, little is known about the thermodynamic factors controlling the extent of heterogeneous nucleation at mineral surfaces exposed to the fluids in environmental systems. In this study, we probed CaCO3 nucleation on pristine quartz (100) surfaces in solution and with nanoscale resolution, by using an in situ grazing incidence small angle X-ray scattering technique. By measuring nucleation rates at different solution supersaturations, we could obtain an effective CaCO3/quartz interfacial free energy value of a' = 36 � 5 mJ/m2 for heterogeneous nucleation. This observation allows quantitative kinetics analysis, and ultimately will lead to precipitation volume estimates that are readily usable in predicting carbonation in many chemical processes and in improving reactive transport models.

In situ probe of interfacial energies for CaCO<sub>3 </sub>heterogeneously nucleated on environmentally relevant substrates

245th National Meeting (2013)

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In situ probe of interfacial energies for CaCO3 heterogeneously nucleated on environmentally relevant substrates

In situ probe of interfacial energies for CaCO₃heterogeneously nucleated on environmentally relevant substrates