Experimental data for the density, viscosity, refractive index and surface tension of four sulfonium-and ammonium-based Ionic Liquids (ILs) with the common bis (trifluoromethylsulfonyl) . Based on the gathered results and on data taken from literature, the impact of the cation isomerism and of the size of the aliphatic tails, as well as the effect resulting from the substitution of a nitrogen by a sulfur atom as the cation central atom, on the thermophysical properties of sulfonium-and ammonium-based ILs is here discussed. Remarkably, more symmetric cations present a lower viscosity for the same, and sometimes even for higher, alkyl chain lengths at the cation. Additional derivative properties, such as the isobaric thermal expansion coefficient, the surface thermodynamic properties and the critical temperature for the investigated ILs were also estimated and are presented and discussed.

No abstract

Experimental data for density, viscosity, refractive index and surface tension of four phosphonium-based ionic liquids were measured in the temperature range between (288.15 and 353.15) K and at atmospheric pressure. The ionic liquids considered include tri(isobutyl) methylphosphonium tosylate, [P i(444) . Additionally, derivative properties, such as the isobaric thermal expansion coefficient, the surface thermodynamic properties and the critical temperatures for the investigated ionic liquids were also estimated and are presented and discussed. Group contribution methods were evaluated and fitted to the density, viscosity and refractive index experimental data.

Density and viscosity experimental data for binary mixtures of 1-alkyl-3-methylimidazolium alkylsulfates + water are reported using four ionic liquids:The choice of the ionic liquids allows us to compare the effects of incrementing the alkyl chain length in the cation and the anion on the measured thermophysical properties behavior. The Gardas and Coutinho group contribution methods were applied to the description of the pure component densities and viscosities allowing the estimation of new group contribution parameters, to extend the applicability of these methods to new ILs. Excess molar volumes and viscosity deviations were calculated and correlated by Redlich−Kister polynomial expansions.