Effect of Nitrile-Functionalization of Imidazolium-Based Ionic Liquids on Their Transport Properties, Both Pure and Mixed with Lithium Salts.

CAPLUS AN 2014:2146289(Journal; Online Computer File)International audienceThe influence of the presence of a nitrile group in the cation of imidazolium-based ionic liquids on their transport properties was investigated. As these liquids can be used as electrolytes in lithium ion batteries, their mixtures with lithium salts were also considered. 1-Butyl-3-methylimidazolium bis(trifluoromethylsulphonyl)imide, [C1C4Im][NTf2], 1-butylnitril-3-methylimidazolium bis(trifluoromethylsulphonyl)imide, [C1C3CNIm][NTf2], and their mixtures with bis(trifluoromethylsulphonyl)imide lithium, Li[NTf2], were studied. Their mass transport properties (viscosity, ionic conductivity, self-diffusion) were experimentally determined. NMR spectroscopy was also used to explore molecular organization and interactions in these systems. The addition of a cyano group increases the viscosity and the ionicity of the liquid. The effect of lithium ion is more pronounced on [C1C3CNIm][NTf2], with interactions between Li+ and the nitrile group

Excess Thermodynamic Properties for Binary Mixtures of Ionic Liquid 1-Ethyl-3-methylimidazolium Ethyl Sulfate and 2-Methoxyethanol from T = (298.15 to 328.15) K at Atmospheric Pressure

The density (rho), speed of sound (u) and refractive index (n (D)) for pure [Emim][EtSO4], 2-methoxyethanol and their binary mixtures were measured using an Anton Paar vibrating tube density and sound velocity meter (DSA 5000 M) and automatic refractometer over the whole composition range as a function of temperature between 298.15 and 328.15 K in steps of 10 K at atmospheric pressure. Experimental values were used to calculate the excess values of molar volumes (), partial molar volumes (), partial molar volumes at infinite dilution (), isentropic compressibility (), acoustic impedance (Z (E)), free length (), speeds of sound (), internal pressure (), free volume () and deviations in refractive index ( ) for the binary mixtures. These properties were fitted to a Redlich-Kister type equation to obtain the binary coefficients and the standard deviations. The negative values of , , ,, and and positive values for Z (E), ,, and indicate the existence of strong interactions between the components. This was further supported by IR spectroscopy analysis