Growth Rate of Calcite Steps As a Function of Aqueous Calcium-to-Carbonate Ratio: Independent Attachment and Detachment of Calcium and Carbonate Ions

Stack, Andrew G.; Grantham, Meg C.

doi:10.1021/cg901395z

Cited by 104 publications

(234 citation statements)

References 19 publications

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“…4a, providing Fig 4b. This is consistent with the observation, previously reported in the literature for calcite growth, that the calcite step velocities and, more generally, the calcite growth rate decrease as the calcium-to-carbonate ratio increases (Nehrke et al, 2007;Larsen et al, 2010;Stack and Grantham, 2010;Bracco et al, 2012;Gebrehiwet et al, 2012). Additionally, the growth of 2D nuclei takes place at [Cd 2+ ] 0 P 0.025 mM (Fig.…”

Section: Growth Kinetics As a Function Of [Cd 2+ ]supporting

confidence: 93%

Kinetics and mechanisms of cadmium carbonate heteroepitaxial growth at the calcite (101¯4) surface

Xu¹,

Kovařík²,

Arey³

et al. 2014

Geochimica et Cosmochimica Acta

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Elucidating the kinetics and mechanisms of heteroepitaxial nucleation and growth at mineral-water interfaces is essential to understanding surface reactivity in geochemical systems. In the present work, the formation of heteroepitaxial cadmium carbonate coatings at calcite-water interfaces was investigated by exposing calcite ð10 1 4Þ surfaces to Cd-bearing aqueous solutions. In situ atomic force microscopy (AFM) was employed as the primary technique. The AFM results indicate that the heteroepitaxial growth of cadmium carbonate proceeds via three different mechanisms depending on the initial supersaturation of the aqueous solution: advancement of existing steps, nucleation and growth of three-dimensional (3D) islands, and nucleation and spread of two-dimensional (2D) nuclei. The 3D islands and 2D nuclei exhibit different morphologies and growth kinetics. The effects of supersaturation on heteroepitaxial growth mechanisms can be interpreted in terms of the free energy barrier for nucleation. At low initial supersaturation, where 3D nucleation dominates, it is hypothesized, from the growth rate and morphology of the 3D islands observed with AFM, that the crystallization of the overgrowth follows a non-classical pathway involving the formation of a surface precursor that is not fully crystalline, whereas high supersaturation favors the formation of crystalline 2D nuclei whose morphology is based on the atomic structure of the calcite substrate. Cross-sectional transmission electron microscopy (TEM) images reveal that the atomic structure of the interface between the cadmium carbonate coating and calcite shows perfect, dislocation-free epitaxy.

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Section: Growth Kinetics As a Function Of [Cd 2+ ]supporting

confidence: 93%

Kinetics and mechanisms of cadmium carbonate heteroepitaxial growth at the calcite (101¯4) surface

Xu¹,

Kovařík²,

Arey³

et al. 2014

Geochimica et Cosmochimica Acta

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“…Since the Iceland spar used in their experiments is visually almost identical to that used in this study, it seems reasonable to recalculate their rates using the specific surface area determined here to see if this reconciles the apparent discrepancies. Their experiments are complicated by the fact that they considered a range of calcium to carbonate ion activities and their effect on the rate of calcite precipitation (Nehrke et al [2007], Stack and Grantham [2010], Gebrehiwet et al [2012]). In this study only a relatively narrow range of calcium to carbonate ion activities from 70-115 was considered [ Table 2].…”

Section: Interpretation Of Rates From Stirred Reactorsmentioning

confidence: 99%

Upscaling calcium carbonate precipitation rates from pore to continuum scale

et al. 2012

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The upscaling of calcite precipitation rates in porous media from the pore (micron) to continuum (centimeter) scale is evaluated with an integrated experimental and modeling approach. Experiments using cylindrical cores packed with glass beads and calcite (Iceland spar) crystals were injected over a period of 28 days with a supersaturated mixture of CaCl 2 and NaHCO 3 to induce calcite growth. Bulk rates of precipitation based on the change in aqueous chemistry over the length of the column are compared with spatially resolved determinations of carbonate precipitation using X-ray synchrotron microtomographic imaging at the micron scale. These data are supplemented by continuously-stirred reactor experiments using the same calcite seed material so as to minimize differences in the effects of reactive site density of the seed material, and to evaluate the rate of precipitation in the absence of transport or "porous medium" effects. Calcite precipitation rates determined in the stirred flowthrough reactor in this study are considerably slower than rates determined at similar supersaturation in unseeded batch experiments by Tang et al. [2008a], although these rates are compatible with those reported in Nehrke et al. [2007] for precipitation on Iceland spar when the same normalization to reactive surface area is used. The nearly linear dependence of the rates on supersaturation cannot be attributed to a diffusion control in the case of the stirred reactors and is likely the result of multi-sourced spiral growth.Integrated precipitation rates based on column effluent chemistry from a higher supersaturation experiment are in good agreement with determinations of total carbonate precipitated based on determination of pre-and post-experiment mass in the column using X-ray microtomography. Using the rates of precipitation determined in the well-stirred flowthrough reactors, it is possible to match the spatially-resolved microtomographic and aqueous data with a coarser resolution continuum model using volume-averaged flow and reactive surface area if the generation of new reactive surface area is accounted for. A nucleation or surface roughening event, which is most pronounced within two millimeters of the column inlet where the supersaturation is highest, is recorded by both BET analysis, which indicates an increase in specific surface area from 0.012 m 2 •g -1 to a value of 0.21 m 2 •g -1 for neoformed calcium carbonate, and by X-ray microtomography. The best fit of the column X-ray microtomography data is provided by simulating calcite precipitation either as a single nearly linear rate for multi-sourced spiral growth, or as two parallel rates that include the spiral growth model and a 2D heterogeneous nucleation model modified by a partial diffusion control, although nucleation needs to be relatively minor on a mass basis in order to match the data. The combined experiments and modeling indicate that it is possible to develop upscaled quantitative models for porous media reactivity, but changes in such propert...

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“…The growth rate depends on solution parameters, such as: the supersaturation index (SI), the ionic strength (I), the pH and the [Ca 2+ ]/[CO 3 2-] ratio [8,[32][33][34][35]. Table 1 compares the results from this study with results from the literature [33][34][35].…”

Section: Single Crystal Growth Rate From Time Lapse Raman Imagesmentioning

confidence: 85%

“…Table 1 compares the results from this study with results from the literature [33][34][35]. Experimental conditions for crystal growth rates vary widely in the literature and importantly influence observed growth rates.…”

Section: Single Crystal Growth Rate From Time Lapse Raman Imagesmentioning

confidence: 93%

Growth Rate and Morphology of a Single Calcium Carbonate Crystal on Polysulfone Film Measured with Time Lapse Raman Micro Spectroscopy

Liszka¹,

Lenferink²,

Otto³

2016

J Anal Bioanal Tech

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Growth Rate of Calcite Steps As a Function of Aqueous Calcium-to-Carbonate Ratio: Independent Attachment and Detachment of Calcium and Carbonate Ions

Cited by 104 publications

References 19 publications

Kinetics and mechanisms of cadmium carbonate heteroepitaxial growth at the calcite (101¯4) surface

Kinetics and mechanisms of cadmium carbonate heteroepitaxial growth at the calcite (101¯4) surface

Upscaling calcium carbonate precipitation rates from pore to continuum scale

Growth Rate and Morphology of a Single Calcium Carbonate Crystal on Polysulfone Film Measured with Time Lapse Raman Micro Spectroscopy

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