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On the Bimodal Effects of Silicic Acids on Calcite Growth

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Pina Martínez, Carlos Manuel and Merkel, Casjen and Guntram, Jordan (2009) On the Bimodal Effects of Silicic Acids on Calcite Growth. Crystal Growth and Design, 9 . pp. 4084-4090. ISSN 1528-7483, ESSN: 1528-7505

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Official URL: https://pubs.acs.org/doi/abs/%2010.1021%2Fcg900333z



Abstract

The effects of silicic acids on calcite growth are a model for the effects of partially polymerized additives on crystal growth. At alkaline pH, silicic acid polymers coexist with small mono- and oligomers. Atomic force microscopy (AFM) showed that large polymers promote two-dimensional nucleation, while mono- and oligomers have a bimodal promoter/inhibitor effect on step propagation. This bimodality can be interpreted as the result of attachment of mono- and oligomers along the steps along with a modification of the kinetics of kink generation and/or propagation. The bimodal step kinematic effect is accompanied by a single morphologic effect: growth islands transform from a rhombus into an ellipse. This effect has been reported for other additives, indicating that many additives generate few morphologies. Such a convergence limits the versatility of chemical control on biomorphogenesis. Contrarily, the strong kinetic effect of silicic acids may make them very efficient controllers of biomorphogenesis, if coupled with a physical shape control, for example, by templates. Thus, silicic acids show a unique bimodality as a controller of calcite biomineralisation and as an abundant biomineral.


Item Type:Article
Uncontrolled Keywords:Silicic acids; Calcite growth; bimodal
Subjects:Sciences > Geology > Crystallography
ID Code:51668
Deposited On:27 Feb 2019 12:01
Last Modified:27 Feb 2019 15:32

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