Phase Equilibrium, Volumetric, and Interfacial Properties of the Ionic Liquid, 1-Hexyl-3-methylimidazolium Bis(trifluoromethylsulfonyl)amide and 1-Octene

Abstract

Biphasic systems involving ionic liquids (ILs) form the basis of many applications in extractions and reactions. In this work, the liquid−liquid phase equilibrium, density, molar volume, excess molar volume, and interfacial and surface tensions are measured for saturated and subsaturated mixtures of 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide ([HMIm][Tf2N]) and 1-octene at four different temperatures, (10, 25, 50, and 75) °C. Many of the properties of the IL phase change significantly with the increasing concentration of 1-octene. The nonrandom two-liquid (NRTL) activity coefficient model was utilized to model the mutual solubility of two liquids. 1-Octene is fairly soluble in the [HMIm][Tf2N], but the IL solubility in the 1-octene is very small. The excess molar volume for the mixture of ILs and 1-octene is slightly negative for all isotherms and becomes more negative with an increase in temperature. The air−liquid surface tension decreases with increasing 1-octene concentration, and the saturated [HMIm][Tf2N] + 1-octene interfacial tension decreases significantly at higher temperatures.

Thermodynamic Properties at Saturation Derived from Experimental Two-Phase Isochoric Heat Capacity of 1-Hexyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide

“…As one can see from Table 3, the present saturated density data for the IL are deviate from the measurements by González et al [15] within 0.22 %. Good agreement within 0.07 % to 0.10 % was observed between the present and the reported density data by Kato and Gmehling [16], Azevedo et al [17], Jacquemin et al [22], Kandil and Marsh [23], and Ahosseini et al [24]. Acceptable agreement within 0.14 %, 0.15 %, 0.17 %, and 0.17 % was found between the present and the data of Iguchi et al [25], Mohammad et al [18], Widegren and Magee [20], and Safarov et al [13], respectively.…”

“…■, Tariq et al [6]; ○, our previous study [27]; △, Safarov et al [13]; □, González et al [15];⟡, Kato and Gmehling [16]; ▲, Azevedo et al [17]; ▼, Muhammad et al [18]; ▽, Esperança et al [19]; ◆, Widegren and Magee [20]; +, Jacquemin et al [22]; ❋, Kandil and Marsh [23]; ⊗, Ahosseini et al [24]; ⊠, Iguchi et al [25]; ●, this work. Solid line is the density of the IL at atmospheric pressure calculated from the IUPAC [1] reference correlation.…”

“…×, this work; ●, Safarov et al [13]; ◆, Widegren and Magee [20]; ▽, Esperança et al [19]; ▼, Muhammad et al [18]; +, Jacquemin et al [22]; ❋, Kandil and Marsh [23]; ⊗, Ahosseini et al [24]; ⊠, Iguchi et al [25]; □, Kato and Gmehling [16]; ○, González et al [15]; △, IUPAC reference correlation [1]. Dashed line is the deviation between the correlations Tariq et al [6] and IUPAC [1]; Solid line is the deviation between the correlations Tariq et al [6] and Azevedo et al [17]…”

Thermal Conductivity of Ionic Liquids: Measurement and Prediction

“…The presented deviations from the IUPAC equation range from about (+0.05 % to −0.6) %, and one datum even deviates by more than −1.2 % [44]. The deviations of other recent density data for [HMIM][NTf 2 ] provided by Jacquemin et al [45], Tariq et al [46], and Ahosseini et al [47] are in the range between (−0.03 and −0.24) %. Our data presented in Table 6 deviates by (−0.50 to −0.58) % from the equation recommended in the IUPAC study, which is distinctly outside the combined uncertainties.…”

Prediction of the binary surface tension of mixtures containing ionic liquids using Support Vector Machine algorithms

“…Table 1 lists the structures of the ILs investigated [75,76]. Table 2 presents the studied binary systems and the range of measured surface tensions (STs) in each system accompanied by the method used for measuring the ST [77][78][79][80][81][82][83][84][85]. After identifying and assembling the data set, the subsequent step was the selection of input variables, which are the model's independent variables.…”