Temperature and Composition Dependence of the Density and Viscosity of Binary Mixtures of Water + Ionic Liquid

Abstract

Density and viscosity were determined for binary mixtures of water and three ionic liquids: 1-ethyl-3methylimidazolium ethylsulfate, 1-ethyl-3-methylimidazolium trifluoroacetate, and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate. The experimental measurements of these properties were carried out at atmospheric pressure and temperatures from (278.15 to 348.15) K. The temperature dependence of density and viscosity for these systems can be described by an empirical second-order polynomial and by the Vogel-Fulcher-Tammann equation, respectively. Excess molar volumes and viscosity deviations were calculated and correlated by Redlich-Kister polynomial expansions. The latter correlations describe the variation of density and viscosity with composition. Comparison of the results for the three binary systems elucidates the influence of the anion on these physical properties.

Thermophysical properties, low pressure solubilities and thermodynamics of solvation of carbon dioxide and hydrogen in two ionic liquids based on the alkylsulfate anion

“…16, 18 These ionic liquids, based on methylsulfate or ethylsulfate anions, are known for their sensitivity to hydrolysis, 3 which is undesired for most applications. This sensibility tends to disappear with the increase of the anion alkyl-side chain, and the ionic liquid 1-butyl-3-methylimidazolium octylsulfate [C 4 C 1 Im][C 8 SO 4 ] is described as stable in the presence of water.…”

Are Ionic Liquids Suitable as New Components in Working Mixtures for Absorption Heat Transformers?

“…The viscosity of {H 2 O + ILs} binary systems decreases because of the weak interaction between the IL anion and cation so the mobility of ions increases and the viscosity decreases [67]. It was noticed that fluorinated anions have lower viscosity than other anions such as alkylsulfates [64].…”

“…Ficke [16] and Seiler et al [50] have shown that the decomposition temperature of [EMIM] + -based ILs ranges between 178°C and 388°C ( Table 2). The decomposition temperature mainly depends on two structural parameters: the nature of the anion and the alkyl chain length [46,[50][51][52][55][56][57][58][59][60][61][62][63][64][65][66][67][68][69][70][71]. Ficke et al [55] i.…”

Developing energy efficient lignin biomass processing – towards understanding mediator behaviour in ionic liquids

“…For example, addition of only a 5 % (v/v) of water to [C 2 mim][C 2 SO 4 ] could lead to reduction in the IL viscosity by 30 %. 37,52 Increasing the concentration of phosphate buffer by more than 10 % (v/v) lowered the peak current measured for ABTS 1. SO 4 ] was examined and is quite similar to that previously seen in buffered aqueous solutions, in terms of proportionality of peak currents to the square root of the scan rate and the ratio of anodic to cathodic peak currents.…”