Nonequilibrium Molecular Simulations of New Ionic Lubricants at Metallic Surfaces: Prediction of the Friction

Mendonça, Ana Catarina Fernandes; Pádua, Agı́lio A. H.; Malfreyt, Patrice

doi:10.1021/ct3008827

Cited by 69 publications

(87 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Again we assign the increase in friction to the lateral structuring and the ordering effect this has on the confined structure of the ionic liquids. Our values for the friction coefficient are similar to those reported in simulations and experiments, including experiments of ionic liquids in contact with metals and mica 18,19,21 .…”

Section: Dependence Of Friction With Substrate Roughness and Normal Loadsupporting

confidence: 87%

“…These results show that in our model the friction coefficient increases with roughness. In previous works, a different type of rough surfaces were considered, namely a conical protrusion 18 , and the friction was found to decrease with respect to the atomically flat surface. The difference in the predicted behaviour, may point towards a complex dependence of the friction coefficient with the topology of the surfaces, which can lead to opposite trends in friction.…”

Section: Dependence Of Friction With Substrate Roughness and Normal Loadmentioning

confidence: 98%

“…This equation has been used before to estimate the friction coefficient of other ionic liquids, both in simulation 18 and experiments 7,19,20 . An analysis of all our friction vs pressure data gives a friction coefficient of µ = 0.02 for the smooth model.…”

Section: Dependence Of Friction With Substrate Roughness and Normal Loadmentioning

confidence: 99%

See 2 more Smart Citations

Electrotunable lubricity with ionic liquids: the influence of nanoscale roughness

et al. 2017

View full text Add to dashboard Cite

The properties of ionic liquids can be modified by applying an external electrostatic potential, providing a route to control their performance in nanolubrication applications. Most computational studies to date have focused on the investigation of smooth surfaces. Real surfaces are generally inhomogeneous and feature roughness of different length scales. We report here a study of the possible effects that surface roughness may have on electrotunable lubricity with ionic liquids, performed here by means of non-equilibrium molecular dynamics simulations. In order to advance our understanding of the interplay of friction and substrate structure we investigate coarse grained models of ionic liquids confined in model surfaces with nanometer roughness. The friction is shown to depend on the roughness of the substrate and the direction of shear. For the investigated systems, the friction coefficient is found to increase with roughness. These results are in contrast with previous studies, where roughness induced reduction of friction was reported, and they highlight the strong sensitivity of the friction process to the structure of the surfaces. The friction force features a maximum at a specific surface charge density. This behaviour is reminiscent of the one reported in ionic liquids confined by flat surfaces, showing the generality of this physical effect in confined ionic liquids. We find that an increase of the substrate-liquid dispersion interactions shifts the maximum to lower surface charges. This effect opens a route to control electrotunable friction phenomena by tuning both the electrostatic potential and the composition of the confining surfaces.

show abstract

Section: Dependence Of Friction With Substrate Roughness and Normal Loadsupporting

confidence: 87%

Section: Dependence Of Friction With Substrate Roughness and Normal Loadmentioning

confidence: 98%

See 1 more Smart Citation

Electrotunable lubricity with ionic liquids: the influence of nanoscale roughness

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Lateral IL nanostructure at solid surfaces has been predicted from a variety of simulations [14][15][16][17][18][19][20][21][22][23][24][25][26][27] but there are few experimental reports.…”

Section: Introductionmentioning

confidence: 99%

Near surface properties of mixtures of propylammonium nitrate with n-alkanols 1. Nanostructure

Elbourne

Cronshaw

Voïtchovsky

et al. 2015

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. * Corresponding author AbstractIn situ amplitude modulated -atomic force microscopy (AM-AFM) has been used to probe the nanostructure of mixtures of propylammonium nitrate (PAN) with n-alkanols near a mica surface. PAN is a protic ionic liquid (IL) which has a bicontinuous sponge-like nanostructure of polar and apolar domains in the bulk, which becomes flatter near a solid surface. Mixtures of PAN with 1-butanol, 1-octanol, and 1-dodecanol at 10 -70 vol% n-alkanol have been examined, along with each pure n-alkanol, to reveal the effect of composition and n-alkanol chain length. At low concentrations the butanol simply swells the PAN nearsurface nanostructure, but at higher concentrations the nanostructure fragments. Octanol and dodecanol first lower the preferred curvature of the PAN near-surface nanostructure because, unlike n-butanol, their alkyl chains are too long to be accommodated alongside the PAN cations. At higher concentrations, octanol and dodecanol self-assemble into n-alkanol rich aggregates in a PAN rich matrix. The concentration at which aggregation first becomes apparent decreases with n-alkanol chain length.2

show abstract

“…Nonequilibrium molecular dynamics for the interaction parameters between alkylammonium alkylsulfonate ILs and an iron surface have been used [92] to develop a procedure for a quantitative prediction of the friction coefficient. Changes in the frictional force are explained in terms of the specific arrangements and orientations of groups forming the ionic liquid at the surface vicinity.…”

Section: Predictive Modelsmentioning

confidence: 99%

Ionic Liquids in Surface Protection

Arias‐Pardilla

Espinosa

Bermúdez

2015

Electrochemistry in Ionic Liquids

View full text Add to dashboard Cite

Nonequilibrium Molecular Simulations of New Ionic Lubricants at Metallic Surfaces: Prediction of the Friction

Cited by 69 publications

References 59 publications

Electrotunable lubricity with ionic liquids: the influence of nanoscale roughness

Electrotunable lubricity with ionic liquids: the influence of nanoscale roughness

Near surface properties of mixtures of propylammonium nitrate with n-alkanols 1. Nanostructure

Ionic Liquids in Surface Protection

Contact Info

Product

Resources

About