The Conductivity of Imidazolium-Based Ionic Liquids from (248 to 468) K. B. Variation of the Anion

The effect of the anion, namely dicyanamide, hexafluorophosphate, trifluoroacetate, or trifluoromethane-sulfonate, on the conductivity (kappa) of 1-N-butyl-3-N-methylimidazolium-based room-temperature ionic liquids (RTILs) was studied over the temperature range (248 to 468) K. The uncertainty in K was estimated to be less than 0.5 %. The conductivity values obtained are well-described by the Vogel-Fulcher-Tammann equation. Additionally, densities (rho) and the corresponding molar conductivities (Lambda) are reported for the temperature range (278 to 338) K. The data for Lambda and the associated viscosities (eta) were found to fit fractional forms of the Walden relationship.