Density, dynamic viscosity, and derived properties of binary mixtures of methanol or ethanol with water, ethyl acetate, and methyl acetate at T=(293.15, 298.15, and 303.15) K

Volume, surface and UNIQUAC interaction parameters for imidazolium based ionic liquids via Polarizable Continuum Model

The refractive index, nD, and density, ρ, of binary mixtures of monoalcohols + water, have been measured at a temperature of 298.15,K and atmospheric pressure. The variation of the refractive indices of these solutions has also been determined with temperature in the range T = (278.15 to 338.15) K and atmospheric pressure. A comparative study has been made of the refractive indices obtained experimentally and those calculated by means of the Lorentz-Lorenz [Theory of Electrons, Dover Phoenix (1952)] and Gladstone-Dale relations [Trans. R. Soc. London 148:887–902 (1858)]; in all cases, the Gladstone–Dale equation was seen to afford values similar to those obtained experimentally. Calculations have been made of the excess molar volumes, VE, and the molar refraction deviations, ΔR, of these mixtures and the differences between the experimental values for refractive index and those obtained by means of the Gladstone–Dale equation. Values of VE were compared with others in the literature. In all cases the VE values were negative, and in all cases, except in the methanol + water, ΔR showed a maximum for x = 0.8.

Refractive Indices, Densities and Excess Molar Volumes of Monoalcohols + Water

We have determined the complex dielectric spectra of ethanol/water mixtures at 25 °C for the nine molar fractions of ethanol, XEA = 004, 008, 011, 018, 03, 05, 07, 09, and 10, in the frequency range 01 ≤ ν/GHz ≤ 89 using TDR in 01 ≤ ν/GHz ≤ 25 and waveguide interferometers in 13 ≤ ν/GHz ≤ 89 At 03 ≤ XEA ≤ 10, a three-step relaxation model turns out to be most appropriate Besides a Cole−Cole relaxation for the dominating low-frequency process (j = 1), assigned to the cooperative dynamics of the H-bond system, which exhibits a pronounced increase of its relaxation time, τ1, when going from XEA = 0 to 1, two additional Debye terms (j = 2 and 3) with the relaxation times of τ2 ≈ 10 ps and τ3 ≈ 1−2 ps are required to reproduce the high-frequency part of the spectrum In view of the well-established relaxation mechanisms of pure liquids, these high-frequency processes can be validly assigned to the motion of singly H-bonded ethanol monomers at the ends of the chain structure (j = 2) and the flipp

Dielectric Relaxation Processes in Ethanol/Water Mixtures

Ternary solutions containing one hydrotrope (such as ethanol) and two immiscible fluids, both being soluble in the hydrotrope at any proportion, show unexpected solubilization power and allow strange but yet unexplained membrane enzyme activity. We study the system ethanol-water-octanol as a simple model of such kinds of ternary solutions. The stability of “detergentless” micelles or microemulsions in such mixtures was proposed in the pioneering works of Barden and coworkers [Smith GD, Donelan CE, Barden RE (1977) J Colloid Interface Sci 60(3):488–496 and Keiser BA, Varie D, Barden RE, Holt SL (1979) J Phys Chem 83(10):1276–1281] in the 1970s and then, neglected, because no general explanation for the observations was available. Recent direct microstructural evidence by light, X-ray, and neutron scattering using contrast variation reopened the debate. We propose here a general principle for solubilization without conventional surfactants: the balance between hydration force and entropy. This balance explains the stability of microemulsions in homogeneous ternary mixtures based on cosolvents.

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How to explain microemulsions formed by solvent mixtures without conventional surfactants.

We report mutual solubilities of water + methyl ethyl ketone and water + methyl propyl ketone at temperatures between 25 and 55 °C, and binodal curves and liquid-liquid equilibria for water + propanoic acid + methyl ethyl ketone and water + propanoic acid + methyl propyl ketone in the same temperature range. UNIQUAC equations fitted the experimental data better than NRTL equations: the average rms phase composition error was 0.2% for UNIQUAC as compared to 0.3% for NRTL, and the rms relative error in the solute distribution ratio was 5% for UNIQUAC as compared to 7.5% for NRTL. © 1995, American Chemical Society. All rights reserved.

Liquid-Liquid Equilibria of the Ternary Mixtures Water + Propanoic Acid + Methyl Ethyl Ketone and Water + Propanoic Acid + Methyl Propyl Ketone

Liquid-liquid equilibrium data are reported for the binary system water + methyl isobutyl ketone over the range 20–55 °C and for the ternary system water + propanoic acid + methyl isobutyl ketone at 25, 35, 45, and 55 °C. The NRTL and UNIQUAC equations have been fitted to the experimental data by optimizing their system-specific parameters; the goodness of fit is satisfactory in both cases. © 1993, American Chemical Society. All rights reserved.

Liquid-Liquid Equilibria of the Ternary System Water + Propanoic Acid + Methyl Isobutyl Ketone at Various Temperatures

The densities, refractive indices, and excess molar volumes of the ternary systems water + methanol + 1-octanol and water + ethanol + 1-octanol have been determined at 298.15 K. The excess volumes have been correlated using Redlich-Kister functions. © 1993, American Chemical Society. All rights reserved.

Densities, refractive indices, and excess molar volumes of the ternary systems water + methanol + 1-octanol and water + ethanol + 1-octanol and their binary mixtures at 298.15 K

This study is part of a wider program of research on the recovery of light alcohols from dilute aqueous solutions using high molecular weight solvents. The authors report liquid-liquid equilibrium data and binodal curves for the systems water + methanol + 1-octanol and water + ethanol + 1-octanol at 25, 35, and 45 C. The data were fitted to the NRTL and UNIQUAC equations.

Liquid-Liquid Equilibria of Water + Methanol + 1-Octanol and Water + Ethanol + 1-Octanol at Various Temperatures

Experimental liquid-liquid equilibrium data obtained at 25 and 35°C for ternary mixtures of MTBE + ethanol + water, and at 25, 35 and 45°C for ternary mixtures of TAME + ethanol + water, were satisfactorily fitted with NRTL and UNI-QUAC equations using the correlation program developed by Sorensen (1980).



Des donnees experimentales d'equilibre liquide—liquide obtenues a 25 et 35°C pour des melanges ternaires de MTBE + ethanol + eau, et a 25, 35 et 45°C pour des melanges ternaires de TAME + ethanol + eau, ont ete calees de maniere satisfaisante par les equations NRTL et UNIQUAC a l'aide du programme de correlations mis au point par Sorensen (1980).

Isabel Vidal

Papers

Liquid-Liquid Equilibria of the Ternary Mixtures Water + Propanoic Acid + Methyl Ethyl Ketone and Water + Propanoic Acid + Methyl Propyl Ketone

Liquid-Liquid Equilibria of the Ternary System Water + Propanoic Acid + Methyl Isobutyl Ketone at Various Temperatures

Densities, refractive indices, and excess molar volumes of the ternary systems water + methanol + 1-octanol and water + ethanol + 1-octanol and their binary mixtures at 298.15 K

Liquid-Liquid Equilibria of Water + Methanol + 1-Octanol and Water + Ethanol + 1-Octanol at Various Temperatures

Liquid-liquid equilibria of (MTBE or TAME) + ethanol + water mixtures