Vapor Liquid Equilibria of 1-Ethyl-3-methylimidazolium Triflate (C₂mimTfO) and n-Alkyl Alcohol Mixtures

Abstract

The isobaric vapor liquid equilibria (VLE) of different binary mixtures of the ionic liquid (IL) 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (C2mimTfO) with the n-alkyl alcohols, methanol, ethanol, propan-1-ol, and butan-1-ol, are studied at the pressures of p = 500, 700, and 1000 mbar, covering a composition range 0.25–0.35 ≤ x(solvent) ≤ 1.0. Complementarily, the experimental results are compared with calculations by the perturbed-chain statistical associating fluid theory (PC-SAFT) equation of state (EoS). For deriving suitable PC-SAFT parameters, experimental liquid densities were determined for the neat IL C2mimTfO and its longer homologues, 1-butyl-3-methylimidazolium trifluoromethanesulfonate (C4mimTfO) and 1-hexyl-3-methylimidazolium trifluoromethanesulfonate (C6mimTfO), in a temperature range of 288.15 K ≤ T ≤ 363.15 K (C2mimTfO) and 293.15 K ≤ T ≤ 363.15 K (C4mimTfO and C6mimTfO), respectively. The PC-SAFT EoS is found to be suitable for describing the VLEs under study with good accuracy (AARDVLE ≤ 0.4%).

Revisiting the Liquid–Liquid Phase Behavior of n-Alkanes and Ethanol

“…Special care was required for the measurements at low temperatures because the influence of the kinetic hindrance of phase separation may become a significant source of error as the viscosity of the samples rises up to high values in the vicinity of a solidifying point. Chemical stability is sometimes a problem for measurements of phase diagrams as well. ,,, In the present study, no signs of decomposition or chemical reaction were observed in any of the systems even at the highest temperatures considered.…”

“…Chemical stability is sometimes a problem for measurements of phase diagrams as well. 51,57,60,61 In the present study, no signs of decomposition or chemical reaction were observed in any of the systems even at the highest temperatures considered.…”

“…The handling of the substances was following our standard procedure for sample preparation of hydrophilic components. ,, For compounds that are solid at room temperature, the procedure was adapted by using solutions for the mixing. The water content specified for the pure compounds was confirmed for all stages of the study.…”

Vapor–Liquid Equilibria of the Ionic Liquid 1-Hexyl-3-methylimidazolium Triflate (C6mimTfO) withn-Alkyl Alcohols

“…In addition, the structure−property relations for the binary mixtures of the C x mimTfO (x = 2, 4, 6) ILs and n-alkyl alcohols (C n OH; n = 1−4) are derived on the basis of this work and previously obtained data. 43,44 ■ EXPERIMENTAL SECTION Materials and Sample Preparation. The IL 1-hexyl-3methylimidazolium trifluoromethanesulfonate (depicted in Figure 1) and the four n-alkyl alcohols methanol, ethanol, propan-1-ol, and butan-1-ol are of commercial origin.…”

“…They were purified and handled following a standard procedure, which is described in detail in our previous works. 27,28,43,44,144 The ionic liquid was degassed and dried under reduced pressure conditions (p < 1 × 10 −2 mbar) at a temperature of T = 308 K for a minimum of t = 24 h. After this time, the loss of mass detected by weighing was less than 10 −3 g when considering a sample containing 20 g of IL. The n-alkyl alcohols methanol and ethanol were used as received without further purification.…”