Interfacial Structures of Trihexyltetradecylphosphonium-bis(mandelato)borate Ionic Liquid Confined between Gold Electrodes
(2017) In ACS Applied Materials and Interfaces 9(5). p.4976-4987- Abstract
Atomistic molecular dynamics simulations have been performed to study microscopic the interfacial ionic structures, molecular arrangements, and orientational preferences of trihexyltetradecylphosphonium-bis(mandelato)borate ([P6,6,6,14][BMB]) ionic liquid confined between neutral and charged gold electrodes. It was found that both [P6,6,6,14] cations and [BMB] anions are coabsorbed onto neutral electrodes at different temperatures. The hexyl and tetradecyl chains in [P6,6,6,14] cations lie preferentially flat on neutral electrodes. The oxalato and phenyl rings in [BMB] anions are characterized by alternative parallel-perpendicular orientations in the mixed innermost ionic layer adjacent to neutral... (More)
Atomistic molecular dynamics simulations have been performed to study microscopic the interfacial ionic structures, molecular arrangements, and orientational preferences of trihexyltetradecylphosphonium-bis(mandelato)borate ([P6,6,6,14][BMB]) ionic liquid confined between neutral and charged gold electrodes. It was found that both [P6,6,6,14] cations and [BMB] anions are coabsorbed onto neutral electrodes at different temperatures. The hexyl and tetradecyl chains in [P6,6,6,14] cations lie preferentially flat on neutral electrodes. The oxalato and phenyl rings in [BMB] anions are characterized by alternative parallel-perpendicular orientations in the mixed innermost ionic layer adjacent to neutral electrodes. An increase in temperature has a marginal effect on the interfacial ionic structures and molecular orientations of [P6,6,6,14][BMB] ionic species in a confined environment. Electrifying gold electrodes leads to peculiar changes in the interfacial ionic structures and molecular orientational arrangements of [P6,6,6,14] cations and [BMB] anions in negatively and positively charged gold electrodes, respectively. As surface charge density increases (but lower than 20 μC/cm2), the layer thickness of the mixed innermost interfacial layer gradually increases due to a consecutive accumulation of [P6,6,6,14] cations and [BMB] anions at negatively and positively charged electrodes, respectively, before the formation of distinct cationic and anionic innermost layers. Meanwhile, the molecular orientations of two oxalato rings in the same [BMB] anions change gradually from a parallel-perpendicular feature to being partially characterized by a tilted arrangement at an angle of 45° from the electrodes and finally to a dominant parallel coordination pattern along positively charged electrodes. Distinctive interfacial distribution patterns are also observed accordingly for phenyl rings that are directly connected to neighboring oxalato rings in [BMB] anions.
(Less)
- author
- Wang, Yong-Lei ; Golets, Mikhail ; Li, Bin LU ; Sarman, Sten and Laaksonen, Aatto
- organization
- publishing date
- 2017-02-08
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- atomistic simulations, gold electrodes, interfacial structures, molecular arrangements, trihexyltetradecylphosphonium-bis(mandelato)borate ionic liquid
- in
- ACS Applied Materials and Interfaces
- volume
- 9
- issue
- 5
- pages
- 12 pages
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- scopus:85011994079
- pmid:28099800
- wos:000393848900080
- ISSN
- 1944-8244
- DOI
- 10.1021/acsami.6b14429
- language
- English
- LU publication?
- yes
- id
- 5de02a87-5a0a-4d72-8e2e-06cfe6e59e59
- date added to LUP
- 2017-02-23 07:48:46
- date last changed
- 2024-03-31 01:46:31
@article{5de02a87-5a0a-4d72-8e2e-06cfe6e59e59,
abstract = {{<p>Atomistic molecular dynamics simulations have been performed to study microscopic the interfacial ionic structures, molecular arrangements, and orientational preferences of trihexyltetradecylphosphonium-bis(mandelato)borate ([P<sub>6,6,6,14</sub>][BMB]) ionic liquid confined between neutral and charged gold electrodes. It was found that both [P<sub>6,6,6,14</sub>] cations and [BMB] anions are coabsorbed onto neutral electrodes at different temperatures. The hexyl and tetradecyl chains in [P<sub>6,6,6,14</sub>] cations lie preferentially flat on neutral electrodes. The oxalato and phenyl rings in [BMB] anions are characterized by alternative parallel-perpendicular orientations in the mixed innermost ionic layer adjacent to neutral electrodes. An increase in temperature has a marginal effect on the interfacial ionic structures and molecular orientations of [P<sub>6,6,6,14</sub>][BMB] ionic species in a confined environment. Electrifying gold electrodes leads to peculiar changes in the interfacial ionic structures and molecular orientational arrangements of [P<sub>6,6,6,14</sub>] cations and [BMB] anions in negatively and positively charged gold electrodes, respectively. As surface charge density increases (but lower than 20 μC/cm<sup>2</sup>), the layer thickness of the mixed innermost interfacial layer gradually increases due to a consecutive accumulation of [P<sub>6,6,6,14</sub>] cations and [BMB] anions at negatively and positively charged electrodes, respectively, before the formation of distinct cationic and anionic innermost layers. Meanwhile, the molecular orientations of two oxalato rings in the same [BMB] anions change gradually from a parallel-perpendicular feature to being partially characterized by a tilted arrangement at an angle of 45° from the electrodes and finally to a dominant parallel coordination pattern along positively charged electrodes. Distinctive interfacial distribution patterns are also observed accordingly for phenyl rings that are directly connected to neighboring oxalato rings in [BMB] anions.</p>}},
author = {{Wang, Yong-Lei and Golets, Mikhail and Li, Bin and Sarman, Sten and Laaksonen, Aatto}},
issn = {{1944-8244}},
keywords = {{atomistic simulations; gold electrodes; interfacial structures; molecular arrangements; trihexyltetradecylphosphonium-bis(mandelato)borate ionic liquid}},
language = {{eng}},
month = {{02}},
number = {{5}},
pages = {{4976--4987}},
publisher = {{The American Chemical Society (ACS)}},
series = {{ACS Applied Materials and Interfaces}},
title = {{Interfacial Structures of Trihexyltetradecylphosphonium-bis(mandelato)borate Ionic Liquid Confined between Gold Electrodes}},
url = {{http://dx.doi.org/10.1021/acsami.6b14429}},
doi = {{10.1021/acsami.6b14429}},
volume = {{9}},
year = {{2017}},
}