Dissipation mechanisms in ionic liquids

The spreading of ionic liquids on molecularly smooth solid surfaces has been little studied in the past. We show that the spreading behaviors of the two ionic liquids, [EMIM] ethyl sulfate and ECOENG™ 500, are well described by the combined molecular kinetic and hydrodynamic model of de Ruijter, de Coninck, and Oshanin [M.J. de Ruijter, J. de Coninck, G. Oshanin, Langmuir 15 (1999) 2209] with reasonable values for the molecular friction coefficient ζ, molecular displacement λ, and frequency K₀ associated with contact line motion, as well as reasonable values for the microscopic cutoff a associated with hydrodynamic dissipation.