Thermophysical, Acoustic, and Refractive Properties of Pure and Binary Mixtures Composed of Imidazolium-Based Ionic Liquids and PEG 600

Abstract

The thermophysical properties of ionic liquids (ILs) can be judiciously modulated by adding suitable co-solvents to make them an economical alternative for various industrial processes. In our search for the better thermophysical properties of these neoteric solvents, herein, we had investigated the thermophysical, acoustic, and refractive properties of imidazolium-based ILs with the bromide counter ion and alkyl chain from butyl to octyl when they are mixed with PEG-600. The density (ρ), speeds of sound (u), and refractive index (n D ) for the pure components of the mixtures and their binary mixture were measured at their whole composition range, and temperature ranges from 293.15 to 323.15 K and at atmospheric pressure. These properties were used to calculate the excess molar volume (V m E ), excess molar isentropic compressibility (K s,m E ), and deviation in refractive index (Δ ϕ n D ) using known relations. These properties were then used to interpret the solute−solute and solute−solvent interactions present in the studied mixtures and to understand the non-ideality within the mixture. Several mixing rules were used to calculate mixtures' refractive indices and correlate with the experimentally measured values. We had further predicted the V m E values of the studied mixtures using the well-known Prigogine−Flory−Patterson theory and extended real association (ERAS) model. Results discussed in this manuscript could help us gain insights to fine-tune the properties of the ILs in a more better and balanced way for several industrial applications.

Viscosity and Density Measurements of Poly(ethyleneglycol) 200 and Poly(ethyleneglycol) 600 at High Pressures

“…The agreement with the present correlation is very good being within 0.04% along the mutual temperature range of both measurements. Patel et al 19 have used an Anton-Paar DSA 5000 digital vibrating tube densimeter for the measurement of the density of PEG 600 with an estimated standard uncertainty of ±0.5 kg•m −3 . The deviations of the data set from Patel et al, 19 such as the one obtained by Noel et al, 17 agree very well with the correlation of the present results, all the deviations being less than 0.05%.…”

“…Deviations of the density, ρ, from the correlation eqs –. For PEG 200: green solid triangle, Ottani et al For PEG 600: purple open circle, Noel et al; yellow open diamond, Zhang et al; and blue open square, Patel et al …”

Insight on Interactions in Binary Mixtures of [EMIM][N(CN)2] with iso- and tert-Butanol: Measurements, Correlations, and DFT Calculations

“…Room-temperature ionic liquids (RTILs), referring to liquids at an ambient temperature, have become an emerging area of research owing to their peculiar characteristics, such as low melting point, nonflammability, negligible vapor pressure (VP), tunable miscibility, and broad liquid range, which have been well explained over the last 2–3 decades. − RTILs are excellent solvents for numerous polar organic compounds. Because of their unique combinations of cations and anions, they can be tailored for specific applications such as fuel cells and Li–air batteries, and their electrocatalytic and redox reactions have been exploited in conventional electrochemical solvents.…”

“…Understanding the fundamental thermophysical properties of pure ILs, their mixtures, and combinations with organic solvents is necessary in examining fluid behavior and developing processes for design and simulation. , Alcohols, with their highly polar H-bond characteristics, are used in organic synthesis reactions and were therefore chosen in this study. Isomeric butanol contains the −OH group at different C-atoms, and the alkyl group branch greatly influences the volumetric and acoustic properties of IL–solvent mixtures.…”

Effect of Isomeric Alcohols on the Thermophysical Properties of Cyano-Based Ionic Liquids: Experimental and Simulation Studies

“…Ionic liquids (ILs) are extensively used as electrolytes, catalysts, absorbents, electrochemistry, and biotechnology owing to their peculiar features, viz., negligible vapor pressure, nonflammability, low melting points, broad liquid range, tunable miscibility, and so forth. − Particularly, the lack of vapor pressure ILs is referred to as green solvents, making them interesting candidates for new applications. The unique combinations of cations (ammonium, pyridinium, and imidazolium) and anions (halide, dicyanamide, trifluoromethane sulfonate, etc.)…”