title: Control of nanoscale friction on gold in an ionic liquid by a potential-dependent ionic lubricant layer.
abstract: The lubricating properties of an ionic liquid on gold surfaces can be controlled through application of an electric potential to the sliding contact. A nanotribology approach has been used to study the frictional behavior of 1-butyl-1-methylpyrrolidinium tris(pentaﬂuoroethyl) triﬂuorophosphate ([Py(1,4)]FAP) confined between silica colloid probes or sharp silica tips and a Au(111) substrate using atomic force microscopy. Friction forces vary with potential because the composition of a confined ion layer between the two surfaces changes from cation-enriched (at negative potentials) to anion-enriched (at positive potentials). This offers a new approach to tuning frictional forces reversibly at the molecular level without changing the substrates, employing a self-replenishing boundary lubricant of low vapor pressure.
authors.affiliation: Centre for Advanced Particle Processing and Transport, The University of Newcastle, Callaghan, NSW 2308, Australia.
authors.forename: James
authors.initials: J
authors.lastname: Sweeney
authors.forename: Florian
authors.initials: F
authors.lastname: Hausen
authors.forename: Robert
authors.initials: R
authors.lastname: Hayes
authors.forename: Grant B
authors.initials: GB
authors.lastname: Webber
authors.forename: Frank
authors.initials: F
authors.lastname: Endres
authors.forename: Mark W
authors.initials: MW
authors.lastname: Rutland
authors.forename: Roland
authors.initials: R
authors.lastname: Bennewitz
authors.forename: Rob
authors.initials: R
authors.lastname: Atkin