Electrotunable friction with ionic liquid lubricants: How important is the molecular structure of the ions?
File(s)il-friction-text-final.pdf (2.69 MB)
Accepted version
Author(s)
Fajardo, OY
Bresme, F
Kornyshev, AA
Urbakh, M
Type
Journal Article
Abstract
Using nonequilibrium molecular dynamics simulations and a coarse-grained model of ionic liquids, we have investigated the impact that the shape and the intramolecular charge distribution of the ions have on the electrotunable friction with ionic liquid nanoscale films. We show that the electric field induces significant structural changes in the film, leading to dramatic modifications of the friction force. Comparison of the present work with previous studies using different models of ionic liquids indicate that the phenomenology presented here applies to a wide range of ionic liquids. In particular, the electric-field-induced shift of the slippage plane from the solid–liquid interface to the interior of the film and the nonmonotonic variation of the friction force are common features of ionic lubricants under strong confinement. We also demonstrate that the molecular structure of the ions plays an important role in determining the electrostriction and electroswelling of the confined film, hence showing the importance of ion-specific effects in electrotunable friction.
Date Issued
2015-10-15
Date Acceptance
2015-09-21
Citation
Journal of Physical Chemistry Letters, 2015, 6 (20), pp.3998-4004
ISSN
1948-7185
Publisher
American Chemical Society
Start Page
3998
End Page
4004
Journal / Book Title
Journal of Physical Chemistry Letters
Volume
6
Issue
20
Copyright Statement
© 2015 American Chemical Society. This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Physical Chemistry Letters, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://dx.doi.org/10.1021/acs.jpclett.5b01802
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Engineering & Physical Science Research Council (EPSRC)
Identifier
https://pubs.acs.org/doi/10.1021/acs.jpclett.5b01802
Grant Number
EP/J003859/1
EP/H004319/1
Subjects
Nanotribology
Ionic liquids
Electric field
Structure
Simulations
Publication Status
Published
Date Publish Online
2015-09-24