Influence of water concentration in the viscosities and densities of cellulose dissolving ionic liquids. Correlation of viscosity data

Abstract

a b s t r a c tThe densities and viscosities of aqueous mixtures of two cellulose dissolving ionic liquids: 1-allyl-3-methylimidazolium chloride and 1-ethyl-3-methyl imidazolium acetate ionic liquids have been experimentally determined for water concentration up to approx. 35% water at atmospheric pressure and temperature range from (298.15 to 373.15) K. Molar excess volumes were calculated, resulting in negative values. Literature viscosity correlations were modified in order to describe the viscosity as a function of temperature and water concentration for both water concentrations lower than x H 2 O = 0.4 and for all the water concentration range. These modified equations were applied to correlate viscosity of (water + -ionic liquid) viscosity data for other 1-alkyl-3-methylimidazolium chloride ionic liquids as well as for (ethanol + 1-ethyl-3-methyl imidazolium acetate) from literature obtaining a good reproducibility of the data.

Experimental determination of viscosities and densities of mixtures carbon dioxide+1-allyl-3-methylimidazolium chloride. Viscosity correlation

“…Densities and viscosities of the pure ionic liquid as a function of temperature are listed in Table 1. In Figure 1 data were plotted together with literature data [ 20], [ 21], [ 22]. It is observed that both, density and viscosity decrease with increasing temperature and that the data determined in this work were consistent with literature data .…”

“…It is observed that both, density and viscosity decrease with increasing temperature and that the data determined in this work were consistent with literature data . [ 20], [ 21], [ 22]…”

The peculiar effect of water on ionic liquids and deep eutectic solvents

“…As an example, the viscosities of ILs/DESs can be decreased significantly by the addition of only a trace amount of water. 33 The mixing of water with ILs/DESs can be either endothermic, exothermic or both, depending on the water content. 34 In addition, the excess volume can be either positive, negative or both, thus generating an S-shaped curve.…”

Rheological Behavior of Mixtures of Ionic Liquids with Water

“…However, the deviation from the logarithmic mixing rule can still be quite significant. Jiménez de la Para et al [30] applied the Grunberg and Nissan [31] mixing rule for describing IL/water mixtures. This approach can be seen as a logarithmic mixing rule extended by correction terms.…”