Density and Refractive Index of Binary Mixtures of Two 1-Alkyl-3-methylimidazolium Ionic Liquids with 1,4-Dioxane and Ethylene Glycol

Abstract

This paper reports experimental data of density and refractive index for the binary systems of 1-butyl-3-methylimidazolium tetrafluoroborate, [Bmim][BF4], with 1,4-dioxane, and 1-ethyl-3-methylimidazolium tetrafluoroborate, [Emim][BF4], with 1,4-dioxane and ethylene glycol (EG). Moreover, for the system [Bmim][BF4] + EG we report here refractive index data. The measurements for the systems with EG were made over the entire composition range at atmospheric pressure (101 ± 2 kPa) and in the temperature range from (293.15 to 353.15) K for densities and from (298.15 to 323.15) K for refractive indices. Because at room temperature the mixtures of both ionic liquids with 1,4-dioxane have indicated partial immiscibility, liquid−liquid phase equilibrium was determined. The excess molar volumes, V E , and deviations in refractive index, Δn, were calculated by using the measured experimental data and correlated by the Redlich−Kister type equations. V E values are positive for the system with EG and negative for both systems with 1,4-dioxane, Δn presenting an opposite sign. To probe the interactions in mixtures and to correlate the excess molar volumes of the mixtures the Prigogine−Flory−Patterson (PFP) theory has been used. Moreover, to correlate V E and predict density and refractive index of the mixtures the Lorentz− Lorenz equation was applied.

Viscosity of binary mixtures of 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid with four organic solvents

“…These results correlate well with our previous results of Prigogine-Flory-Patterson (PFP) theory used to analyse the excess molar volumes [20,21].…”

“…The temperature range was till 343.15 K for the system with ACN because of its boiling point. Also, the system with 1,4-dioxane, which shows partial immiscibility at low mole fraction of the ionic liquid, was investigated over the miscibility domain, which is given in our previous article [21]. The relative deviations of viscosity reported by Fan et al [22] …”

“…We took the volumetric data necessary in equation (5) from our previously published papers [20,21]. The experimental values of ∆η and G *E have been fitted to the Redlich-Kister type polynomials:…”

“…Combined viscosity and density values were used to calculate the excess Gibbs energy of activation of viscous flow. We already have published the density values for these binary systems [20,21] [20,21]. All measurements were made at atmospheric pressure, p = 0.1 MPa, which was measured in our laboratory by a mercury barometer with an uncertainty of ±0.002 MPa.…”

Hydrogen Bonding in 1‐Propanol‐Ethanol Binary Mixture: Experimental and Modeling Approaches

“…[3][4][5] Hence, much research has been done in studying the properties of binary solutions. Dielectric properties, [6,7] refractive indices, [8][9][10][11] viscosities, [12,13] IR spectra [14,15] and excess parameters [16][17][18] of different binary liquids have been studied. Binary mixtures of alcohols with water have been investigated [19][20][21] for their significant hydrogen bonding [22] that can alter physical properties.…”