Milek T, Zahn D (2016)
Publication Type: Journal article
Publication year: 2016
Book Volume: 642
Pages Range: 902-905
Journal Issue: 16
Molecular dynamics simulations unravel the association of citrate to (10--10) and (000--1) growth fronts of zinc oxide and demonstrate an unexpected mobility of the surfactant. Citrate association to perfectly planar (10--10) and (000--1) ZnO-ethanol interfaces was found to be favored over dissociation by 1.5--2 eV hence suggesting strongly bound, immobilized surfactants. However, intramolecular stress prevents binding of all three carboxyl groups to planar surfaces and the typical arrangement is that of two carboxyl-Zn contacts (including two salt bridges each) whilst the remaining carboxyl group is dangling into the solvent. As a consequence, the surfactant exhibits a 'walking' mechanism to move along the surface by exchanging the role of its carboxyl groups. This finding has strong implications for the role of citrate during crystal growth as illustrated by a recently developed simulation scheme based on hundreds of individual Zn2+ and OH-- ion association steps. In particular, for the (10--10) surface -- which grows via formation of ridges embedded by (10--10) faces -- these simulations show how citrate ions move towards steps and bind to the growth front by additional 4 eV per surfactant molecule.
APA:
Milek, T., & Zahn, D. (2016). A Surfactants Walk to Work: Modes of Action of Citrate Controlling (10-10) and (000-1) Zinc Oxide Surface Growth from Solution. Zeitschrift für Anorganische und Allgemeine Chemie, 642(16), 902-905. https://dx.doi.org/10.1002/zaac.201600147
MLA:
Milek, Theodor, and Dirk Zahn. "A Surfactants Walk to Work: Modes of Action of Citrate Controlling (10-10) and (000-1) Zinc Oxide Surface Growth from Solution." Zeitschrift für Anorganische und Allgemeine Chemie 642.16 (2016): 902-905.
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