The Molar Surface Gibbs Free Energy And Estimate Of Polarity For A New Ether-Functionalized Ionic Liquid [C(2)2o1im][Dca]

A new ether-functionalized ionic liquid (IL), 1-ethyl-3-(2-methoxyethyl)-imidazolium dicyanamide, [C(2)2O1IM][DCA], was prepared and characterized. The values of density, surface tension and refractive index of the IL were measured at T = (298.15-338.15) K by using standard addition method (SAM) and the values of the molar surface Gibbs free energy were also calculated so that the molar surface entropy and the molar surface enthalpy of the IL were obtained. Using the concept of the molar surface Gibbs free energy, the traditional Eotvos equation was transformed into a modified Eotvos equation which can be well applied to the IL. In terms of the new scale of polarity for ILs, the polarity of [C(2)2O1IM][DCA] and 11 molecular liquids were estimated. The results show that the polarity order of these molecular liquids predicted by the dielectric constant is consistency with its estimated by the new scale of polarity for ILs. (C) 2017 Published by Elsevier Ltd.