Molecular Ordering of Ethanol at the Calcite Surface
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| Title: | Molecular Ordering of Ethanol at the Calcite Surface |
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| Authors: | Sanchez Pasarin, Ivan Jesus, Yang, Mingjun, Bovet, Nicolas Emile, Glyvradal, Magni, Nielsen, Martin Meedom, Bohr, Jakob, Feidenhans'l, Robert Krarup, Stipp, Susan Louise Svane |
| Source: | Langmuir 28, 2545-50 (2012). doi:10.1021/la2021758 |
| Publisher Information: | American Chemical Society (ACS), 2012. |
| Publication Year: | 2012 |
| Subject Terms: | Models, Molecular, Calcium Carbonate: chemistry, Ethanol, Surface Properties, Ethanol: chemistry, 02 engineering and technology, Molecular Dynamics Simulation, 0210 nano-technology, 01 natural sciences, Calcium Carbonate, 0104 chemical sciences |
| Description: | To produce biominerals, such as shells, bones, and teeth, living beings create organic compounds that control the growth of the solid phase. Investigating the atomic scale behavior of individual functional groups at the mineral-fluid interface provides fundamental information that is useful for constructing accurate predictive models for natural systems. Previous investigations of the activity of coccolith-associated polysaccharides (CAP) on calcite, using atomic force microscopy (AFM) [Henriksen, K., Young, J. R., Bown, P. R., and Stipp, S. L. S. Palentology 2004, 43 (Part 3), 725-743] and molecular dynamics (MD) modeling [Yang, M., Stipp, S. L. S., and Harding, J. H. Cryst. Growth Des. 2008, 8 (11), 4066-4074], have suggested that OH functional groups control polysaccharide attachment. The purpose of this work was to characterize, using X-ray reflectivity (XR) combined with molecular dynamics (MD) simulations, the structuring on calcite of a layer of the simplest carbon chain molecule that contains an OH group, ethanol (CH(3)-CH(2)-OH). We found evidence that EtOH forms a highly ordered structure at the calcite surface, where the first layer molecules bond with calcite. The ethanol molecules stand up perpendicularly at the interface or nearly so. As a consequence, the fatty, CH(3) ends form a new surface, about 6 Å from the termination of the bulk calcite, and beyond that, there is a thin gap where ethanol density is low. Following is a more disordered layer that is two to three ethanol molecules thick, about 14 Å, where density more resembles that of bulk liquid ethanol. The good agreement between theory and experiment gives confidence that a theoretical approach can offer information about behavior in more complex systems. |
| Document Type: | Article |
| Language: | English |
| ISSN: | 1520-5827 0743-7463 |
| DOI: | 10.1021/la2021758 |
| Access URL: | https://pubmed.ncbi.nlm.nih.gov/22060260 https://www.ncbi.nlm.nih.gov/pubmed/22060260 https://pubs.acs.org/doi/10.1021/la2021758 https://pubag.nal.usda.gov/catalog/5766892 https://orbit.dtu.dk/en/publications/molecular-ordering-of-ethanol-at-the-calcite-surface(6de29eef-9abd-41c1-acb7-814bff242d29)/export.html https://bib-pubdb1.desy.de/record/144104 |
| Accession Number: | edsair.doi.dedup.....e10af8ad36e96e49edf7d434b484830e |
| Database: | OpenAIRE |
Nájsť tento článok vo Web of Science | Abstract: | To produce biominerals, such as shells, bones, and teeth, living beings create organic compounds that control the growth of the solid phase. Investigating the atomic scale behavior of individual functional groups at the mineral-fluid interface provides fundamental information that is useful for constructing accurate predictive models for natural systems. Previous investigations of the activity of coccolith-associated polysaccharides (CAP) on calcite, using atomic force microscopy (AFM) [Henriksen, K., Young, J. R., Bown, P. R., and Stipp, S. L. S. Palentology 2004, 43 (Part 3), 725-743] and molecular dynamics (MD) modeling [Yang, M., Stipp, S. L. S., and Harding, J. H. Cryst. Growth Des. 2008, 8 (11), 4066-4074], have suggested that OH functional groups control polysaccharide attachment. The purpose of this work was to characterize, using X-ray reflectivity (XR) combined with molecular dynamics (MD) simulations, the structuring on calcite of a layer of the simplest carbon chain molecule that contains an OH group, ethanol (CH(3)-CH(2)-OH). We found evidence that EtOH forms a highly ordered structure at the calcite surface, where the first layer molecules bond with calcite. The ethanol molecules stand up perpendicularly at the interface or nearly so. As a consequence, the fatty, CH(3) ends form a new surface, about 6 Å from the termination of the bulk calcite, and beyond that, there is a thin gap where ethanol density is low. Following is a more disordered layer that is two to three ethanol molecules thick, about 14 Å, where density more resembles that of bulk liquid ethanol. The good agreement between theory and experiment gives confidence that a theoretical approach can offer information about behavior in more complex systems. |
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| ISSN: | 15205827 07437463 |
| DOI: | 10.1021/la2021758 |