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{Di:2020:10.1021/acsami.9b19283,
author = {Di, Lecce S and Kornyshev, AA and Urbakh, M and Bresme, F},
doi = {10.1021/acsami.9b19283},
journal = {ACS Applied Materials and Interfaces},
pages = {4105--4113},
title = {Electrotunable lubrication with ionic liquids: the effects of cation chain length and substrate polarity.},
url = {http://dx.doi.org/10.1021/acsami.9b19283},
volume = {12},
year = {2020}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Electrotunable lubrication with ionic liquids (ILs) provides dynamic control of friction with the prospect to achieve superlubrication. We investigate the dependence of the frictional and structural forces with 1-n,2-methyl-imidazolium tetrafluoroborate [C                        n                    MIM]+[BF4]- (n = 2, 4, 6) ILs as a lubricant on the molecular structure of the liquid, normal load, and polarity of the electrodes. Using non-equilibrium molecular dynamics simulations and coarse-grained force-fields, we show that the friction force depends significantly on the chain length of the cation. ILs containing cations with shorter aliphatic chains show lower friction forces, ∼40% for n = 2 as compared to the n = 6 case, and more resistance to squeeze-out by external loads. The normal load defines the dynamic regime of friction, and it determines maxima in the friction force at specific surface charges. At relatively low normal loads, ∼10 MPa, the velocity profile in the confined region resembles a Couette type flow, whereas at high loads, >200 MPa, the motion of the ions is highly correlated and the velocity profile resembles a "plug" flow. Different dynamic regimes result in distinctive slippage planes, located either at the IL-electrode interface or in the interior of the film, which ultimately lead, at high loads, to the observation of maxima in the friction force at specific surface charge densities. Instead, at low loads the maxima are not observed, and the friction is found to monotonously increase with the surface charge. Friction with [C                        n                    MIM]+[BF4]- as a lubricant is reduced when the liquid is confined between positively charged electrodes. This is due to better lubricating properties and enhanced resistance to squeeze out when the anion [BF4]- is in direct contact with the electrode.
AU  - Di,Lecce S
AU  - Kornyshev,AA
AU  - Urbakh,M
AU  - Bresme,F
DO  - 10.1021/acsami.9b19283
EP  - 4113
PY  - 2020///
SN  - 1944-8244
SP  - 4105
TI  - Electrotunable lubrication with ionic liquids: the effects of cation chain length and substrate polarity.
T2  - ACS Applied Materials and Interfaces
UR  - http://dx.doi.org/10.1021/acsami.9b19283
UR  - https://www.ncbi.nlm.nih.gov/pubmed/31875392
UR  - https://pubs.acs.org/doi/10.1021/acsami.9b19283
UR  - http://hdl.handle.net/10044/1/76488
VL  - 12
ER  -
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