A Volumetric and Viscosity Study for the Binary Mixtures of Ammonium-Based Asymmetrical Gemini Ionic Liquids with Alcohols at T = 293.15–333.15 K

Abstract

In this work, the experimental densities and dynamic viscosities of binary mixtures of ammonium-based roomtemperature asymmetrical Gemini ionic liquids (GILs) 1-trimethylammonium-3-(pyridinium) propane bisdicyanamide ([N 111 C 3 Py][DCA] 2 ) and 1-trimethylammonium-3-(1-methylpiperidinium) propane bisdicyanamide ([N 111 C 3 MPi][DCA] 2 ) with methanol (MeOH) or ethanol (EtOH) over the entire concentration range were, respectively, determined experimentally at temperatures of (293.15, 303.15, 313.15, 323.15, and 333.15) K in the atmospheric pressure of 0.1 MPa. The excess molar volumes (V m E ), excess dynamic viscosities (Δη), and excess Gibbs energy of activation (ΔG* E ) of the mixtures were evaluated according to the experimental ρ and η values of pure [N 111 C 3 Py][DCA] 2 , [N 111 C 3 MPi][DCA] 2 , MeOH, EtOH, and their binary solutions at the investigated temperatures and pressure. The change of V mE and Δη were correlated with the Redlich− Kister-type expression and optimal fitting parameters were evaluated. It was observed that values of V m E and Δη are negative deviations from ideal behaviors for the four binary systems. With the mole fraction of alcohol decreasing, these excess properties for these mixtures exist as more negative deviations from ideal solutions, until minimum excess values are reached. Negative values of V m E and Δη for the four binary solutions indicate stronger interactions between GIL and alcohol molecules compared to the pure components and better packing owing to the differences in size and shape of the investigated molecules. Positive values of ΔG* E can be ascribed to the size effect of mixing components. Meanwhile, the dependence of these excess properties on temperature for all binary systems indicates that the temperature has a great influence on intermolecular interactions in the studied mixtures.

Density, Viscosity, and Refractive Index for Binary Mixtures of Three Adamantane Derivatives with n-Nonane or n-Undecane at T = 293.15–343.15 K and Atmospheric Pressure

“…The viscosity values were obtained from the rolling time of a stainless ball in a liquid sample. The values of sample viscosity were directly automatically calculated according to the rolling time . The automatic microviscometer can control the temperature and rolling time with an uncertainty of 0.01 K and 0.001 s, respectively.…”

“…The values of sample viscosity were directly automatically calculated according to the rolling time. 25 The automatic microviscometer can control the temperature and rolling time with an uncertainty of 0.01 K and 0.001 s, respectively. In addition, the viscometer is calibrated by employing ultrapure water, and the relative expanded uncertainty in this work is 0.02.…”

Intermolecular Interactions between 1-Ethyl-3-methylimidazolium-Based Ionic Liquids with Carboxylic Acid at Different Temperatures via Thermodynamic and Spectroscopic Studies

“…With an increase in temperature, the number of the free dipoles of carboxylic acid molecules in the mixture increases due to dissociation of existing bonds and more interaction with available ions of the IL, leading to a decrease in V m E with temperature. 87 Also, the decrease in the V m E with temperature can be attributed to the greater packing efficiency 88 between the mixing components due to the expansion in free volume between the IL ions with temperature.…”

Thermophysical Properties of Mixtures of 2-Ethylhexanoic Acid and Ethanol

“…FigureS3: Density of pure ethanol at 101.3 kPa as a function of temperature. Symbols are experimental results from this work and measurement data from the literature[3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] as denoted in the legend. The line denotes the fit of the data of this work as described in the main text.…”

“…FigureS4: Relative deviation between experimental densities from this work or literature[3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] as denoted in the legend and the fit to this work's data as described in the main text.…”