Study Of The Properties For Binary Mixtures Of Containing Ionic Liquids Of Oligoether Carboxylates

In this paper, the methods of synthesis and purification of a new kind of ionic liquids—sodium 2,5,8,11-tetraoxatridecan-13-oate ([Na][TOTO]) were improved. The structure and purity of [Na][TOTO] were confirmed by 1H-NMR spectrum,13C-NMR spectrum, themogravimetic analysis(TGA), elemental analysis(EL) and infrared spectrum(IR). Densities, viscosities and electrical conductivities for three binary mixtures ([Na][TOTO]+water, [Na][TOTO]+ethanol and [Na][TOTO]+methanol) have been measured at the temperature range from 298.15K～333.15K over the entire composition. From these data, excess molar volumes, excess viscosities, isobaric thermal expansivities, molar electrical conductivities and partial molar volumes were calculated.The results show that the densities linearly decrease, while the viscosities exponentially decrease and the electrical conductivities exponentially increase with increasing temperature. These data of viscosities and electrical conductivities could be correlated using the Arrhenius equation. The densities of ionic liquid mixtures decrease with increasing composition of solvents, and this trend can be correlated by an empirical equation. The viscosities of binary mixtures fall sharply with increasing composition of solvents at first, and then gradually approach to the viscosities of pure solvents. With the addition of solvents, the electrical conductivities of mixtures increase in the high concentration range of ionic liquids, but decrease in the infinite dilution.The excess molar volumes and excess viscosities are all negative for these three mixtures and all these excess properties can be correlated using four-parameter Redlich-Kister equation with satisfying results. The partial molar volumes at infinite dilution of ionic liquids linearly increase with increasing temperature. With increasing composition of ionic liquids, the isobaric thermal expansivities of ([Na][TOTO]+ water) increase dramatically at first, and then gradually level off, while the isobaric thermal expansivities of ([Na][TOTO]+ethanol) and ([Na][TOTO]+methanol) increase gradually. The effect of concentration of ionic liquids on the molar electrical conductivity has been examined using the Walden rule with satisfying results.