Imperial College London
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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:2020:10.1021/acsanm.0c01946,
author = {Pivnic, K and Bresme, F and Kornyshev, AA and Urbakh, M},
doi = {10.1021/acsanm.0c01946},
journal = {ACS Applied Nano Material},
pages = {10708--10719},
title = {Electrotunable friction in diluted room temperature ionic liquids: implications for nanotribology},
url = {http://dx.doi.org/10.1021/acsanm.0c01946},
volume = {3},
year = {2020}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Using nonequilibrium molecular dynamics (NEMD) simulations, we study the mechanism of electrotunable friction in the mixture of a room temperature ionic liquid (RTIL), BMIM PF6, and an organic solvent, acetonitrile. The dilution itself helps to reduce the viscosity and thereby reduce the viscous contribution to friction. At the same time, we find that under nanoscale confinement conditions, diluted RTIL solutions, of just ∼10% molar fraction, still feature a remarkable variation of the friction force with the electrode surface charge density, not weaker than had been earlier shown for nanoconfined pure RTILs. In both classes of systems the electrotunable friction response is due to accumulation of counterions at charged surfaces. For both diluted mixtures and pure RTILs, the friction force is minimal for uncharged surfaces and it increases with surface charge of either sign but only in the range of low and moderate surface charges (16–32 μC/cm2). At higher surface charges (43–55 μC/cm2), the effect is different: in the pure RTIL, the friction force continues to increase with the surface charge, while in the diluted RTIL mixture it features a maximum, with a reduction of friction with the increasing surface charge. This contrasting behavior is explained by the difference in the slip conditions found for the pure and the diluted RTIL solutions in contact with highly charged surfaces. Overall, we demonstrate that nanoscale films of diluted mixtures of RTIL provide lower friction forces than the pure RTIL films, preserving at the same time a significant electrotunable response when the liquids are confined between symmetrically charged surfaces. Nanoconfinement between asymmetrically charged surfaces leads to a reduction of friction compared to the symmetric case, with a concomitant decrease in the range of friction variation with the surface charge density. Our results highlight the potential of diluted RTIL mixtures as cost-effective electrotunab
AU  - Pivnic,K
AU  - Bresme,F
AU  - Kornyshev,AA
AU  - Urbakh,M
DO  - 10.1021/acsanm.0c01946
EP  - 10719
PY  - 2020///
SN  - 2574-0970
SP  - 10708
TI  - Electrotunable friction in diluted room temperature ionic liquids: implications for nanotribology
T2  - ACS Applied Nano Material
UR  - http://dx.doi.org/10.1021/acsanm.0c01946
UR  - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000595546500018&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR  - https://pubs.acs.org/doi/10.1021/acsanm.0c01946
UR  - http://hdl.handle.net/10044/1/87981
VL  - 3
ER  -
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