Thermodynamic Properties of Binary Mixtures of Water and Room-Temperature Ionic Liquids: Vapor Pressures, Heat Capacities, Densities, and Viscosities of Water + 1-Ethyl-3-methylimidazolium Acetate and Water + Diethylmethylammonium Methane Sulfonate

Abstract

Vapor–liquid equilibria (VLE), heat capacities, densities, and viscosities of mixtures of water and 1-ethyl-3-methylimidazolium acetate ([EMIM]­[OAc]) and mixtures of water and diethylmethylammonium methane sulfonate ([DEMA]­[OMs]) were measured in the temperature range T = (293.15 to 353.15) K. VLE measurements were carried out by Fourier transform infrared (FTIR) spectroscopy in a dynamic cell, and the experimental VLE data were correlated to the nonrandom two-liquid (NRTL) model. Measurements of the heat capacity were conducted via differential scanning calorimetry (DSC). The density was measured with a pycnometer and the viscosity with a falling-sphere viscometer.

Influence of water concentration in the viscosities and densities of cellulose dissolving ionic liquids. Correlation of viscosity data

“…In figure 2, comparison of measured densities of the binary mixture (water + C 2 mimAc) with those of literature are shown. Our data are consistent with those of Quijada et al [17]. Even when literature data were determined at different water concentration ranges, the data exhibit the same tendency than the data of Romich et al [18].…”

“…In figure 1, experimental and literature viscosities of the system (water + C 2 mimAc) are compared. In general measurements are in good agreement with literature data [16][17][18][19][20]. At lower temperatures and water concentration discrepancies in viscosity are higher probably due to the high hygroscopicity of the ILs used and the difficulty in keeping the water content constant across the measurement procedure.…”

“…For both ILs viscosities decrease when increasing temperature and water concentration as described in literature [4,8,9,13,14,[16][17][18].…”

“…Araujo et al [15] determined viscosities of C 2 mimAc with nucleic acid bases. Quijada et al [16] determined the viscosities and densities of mixtures of (water + ethanol) with C 2 mimAc at temperatures from (298 to 343) K. Romich et al [17] determined viscosities and densities of mixtures (water + C 2 mimAc) at temperatures from (293 to 353) K at water molar fractions higher than 0.34. Fendt et al [18] determined the viscosities of mixtures of C 2 mimAc, C 4 mimAc and other acetate ILs) with water and other solvents such as 1,2-ethanediol, acetonitrile, dimethylformamide at T = 298 K using a concentric cylinders viscometer.…”

Are Ionic Liquids Suitable as New Components in Working Mixtures for Absorption Heat Transformers?

“…This may enlarge the AHT size (exchange area) and increase the power required for the pumping process [63]. Nevertheless, various publications [26,31,[33][34][35] stated that viscosity of ILs sharply decreases when temperature increases and/or ILs are mixed with water. Taking into account that AHT has a high generator and absorber temperature (between 80 and 150°C), the viscosity of the {H 2 O + ILs} should not be a limitation for their use as absorbents in AHT [36].…”