  Ionic Liquids feature thermophysical properties that are of interest in
solvents, energy storage materials and tenable lubrication applications.
Recently, a series of coarse grained (CG) models was developed to investigate
1-ethyl-3-methylimidazolium tetrafluoroborate [C2MIM][BF4] and
1-butyl-3-methylimidazolium hexafluorophosphate [C4MIM][PF6] ionic liquids.
Building on these CG models we derive force-fields to investigate the
[C_{2-8}MIM] [BF4] family of ionic liquids, as a starting step for systematic
investigations of lubrication under nanoconfinement conditions. The simualted
equation of state and diffusion coefficients are in good agreement with
experimental data and with all-atom force fields. We use these model to analyze
the nano nanostructuring of ILs characteristic of cations with longer aliphatic
chains as well as the ILs liquidvapour interfacial structure. The CG nature of
these models enables the simulation of very long time scales, which are needed
to computer reliable results of dynamic and interfacial properties. For
[C>4MIM] [BF4] the break in symmetry associated to the liquid-vapor interface
induces nanostructuring in polar and non-polar domains in the direction
perpendicular to the interface plane, hence mimicking the behavior observed in
the bulk phases.
