Imperial College London
Portrait Picture

ProfessorAlexeiKornyshev

Faculty of Natural Sciences, Department of Chemistry

Professor of Chemical Physics
 
 
 
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Contact

 

+44 (0)20 7594 5786a.kornyshev Website CV

 
 
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Assistant

 

Mr John Murrell +44 (0)20 7594 2845

 
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Location

 

110Molecular Sciences Research HubWhite City Campus

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Summary

 

Publications

Citation

BibTex format

@article{Pivnic:2019:10.1021/acs.langmuir.9b02121,
author = {Pivnic, K and Bresme, F and Kornyshev, AA and Urbakh, M},
doi = {10.1021/acs.langmuir.9b02121},
journal = {Langmuir: the ACS journal of surfaces and colloids},
pages = {15410--15420},
title = {Structural forces in mixtures of ionic liquids with organic solvents},
url = {http://dx.doi.org/10.1021/acs.langmuir.9b02121},
volume = {35},
year = {2019}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Using molecular dynamics simulations, we study the impact of electrode charging and addition of solvent (acetonitrile, ACN) on structural forces of the BMIM PF6 ionic liquid (IL) confined by surfaces at nanometer separations. We establish relationships between the structural forces and the microscopic structure of the confined liquid. Depending on the structural arrangements of cations and anions across the nanofilm, the load-induced squeeze-out of liquid layers occurs via one-layer or bilayer steps. The cations confined between charged plates orient with their aliphatic chain perpendicular to the surface planes and link two adjacent IL layers. These structures facilitate the squeeze-out of single layers. For both pure IL and IL-ACN mixtures, we observe a strong dependence of nanofilm structure on the surface charge density, which affects the simulated pressure–displacement curves. Addition of solvent to the IL modifies the layering in the confined film. At high electrode charges and high dilution of IL (below 10% molar fraction), the layered structure of the nanofilm is less well defined. We predict a change in the squeeze-out mechanism under pressure, from a discontinuous squeeze-out (for high IL concentrations) to an almost continuous one (for low IL concentrations). Importantly, our simulations show that charged electrodes are coated with ions even at low IL concentrations. These ion-rich layers adjacent to the charged plate surfaces are not squeezed out even under very high normal pressures of ∼5 GPa. Hence, we demonstrate the high performance of IL–solvent mixtures to protect surfaces from wear and to provide lubrication at high loads.
AU  - Pivnic,K
AU  - Bresme,F
AU  - Kornyshev,AA
AU  - Urbakh,M
DO  - 10.1021/acs.langmuir.9b02121
EP  - 15420
PY  - 2019///
SN  - 0743-7463
SP  - 15410
TI  - Structural forces in mixtures of ionic liquids with organic solvents
T2  - Langmuir: the ACS journal of surfaces and colloids
UR  - http://dx.doi.org/10.1021/acs.langmuir.9b02121
UR  - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000500039900047&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR  - http://hdl.handle.net/10044/1/76460
VL  - 35
ER  -
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