The effect of the anion, namely dicyanamide, hexafluorophosphate, trifluoroacetate, or trifluoromethanesulfonate, on the conductivity (κ) 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 κ was estimated to be less than 0.5 %. The conductivity values obtained are well-described by the Vogel-Fulcher-Tammann equation. Additionally, densities (F) and the corresponding molar conductivities (Λ) are reported for the temperature range (278 to 338) K. The data for Λ and the associated viscosities (η) were found to fit fractional forms of the Walden relationship.

Data for the conductivity (κ) of the ionic liquids [emim][BF4], [bmim][BF4], [hmim][BF4], and [omim][BF4] from (−35 to 195) °C are reported. The data can be well-fit with the Vogel−Fulcher−Tammann equation. Additionally, molar conductivities (Λ) were determined for the limited temperature range of (5 to 65) °C. Walden plots of these data indicate that the investigated compounds can be classified as “high-ionicity” ionic liquids. It is suspected that the large difference between the present κ values and some of the literature values is mainly due to the neglect of BF4 − hydrolysis.

In this investigation we present for the first time microemulsions comprising an ionic liquid as surfactant and a room-temperature ionic liquid as polar pseudo-phase. Microemulsions containing the long-chain ionic liquid 1-hexadecyl-3-methyl-imidazolium chloride ([C 16 mim][Cl]) as surfactant, decanol as cosurfactant, dodecane as continuous phase and room temperature ionic liquids (ethylammonium nitrate (EAN) and 1-butyl-3methylimidazolium tetrafluoroborate ([bmim]][BF 4 ]), respectively) as polar microenvironment have been formulated. The phase diagrams of both systems were determined at a constant surfactant/cosurfactant molar ratio. EAN microregions in oil have been confirmed with conductivity measurements. In presence of EAN a model of dynamic percolation could be applied. Dynamic light scattering (DLS) measurements indicated a swelling of the formed nano-structures with increasing amount of EAN, a linear dependence of the hydrodynamic radii on the EAN weight fraction was observed. Both systems exhibited a single broad peak in SAXS and follow a characteristic q -4 dependence of the scattering intensity at large q values. The Teubner-Strey model was successfully used to fit the spectra giving f a , the amphiphilic factor, and the two characteristic length scales of microemulsions, namely the periodicity, d, and the correlation length, ζ. Furthermore, the specific area of the interface could be determined from the Porod limit and the experimental invariant. The amphiphilic factor clearly demonstrated structural differences between the two systems confirming that the nature of the polar ionic liquid plays an important role on the rigidity of the interfacial film. The adaptability of three different models ranging from spherical ionic liquid in oil over repulsive spheres to bicontinuous structures has been checked.