A group contribution method to estimate the viscosity of ionic liquids at different temperatures

Computer‐aided design of ionic liquids as solvents for extractive desulfurization

“…In the present work, the third method is employed mainly because it divides cations, anions, and substituents separately and thereby enlarges the design space and the flexibility of the CAILD approach significantly. Moreover, most available GC models for predicting IL physical properties also decompose ILs in this manner, which means the UNIFAC‐IL model used here can be easily combined with the physical property models when formulating the final CAILD problem.…”

“…In addition to the structural and thermodynamic property constraints, some fundamental physical properties, especially the melting point ( T m ) and the viscosity ( η ), are important criteria for determining the suitability of ILs as extraction solvents and thus should be taken into account during IL design . In this work, the following two physical property constraints are added …”

“…Such constraints ensure that the selected ILs are applicable as solvents at room temperature and have relatively low viscosity, thus can be pumped at moderate pressure drop. Two GC models developed by Lazzús and Lazzús and Pulgar‐Villarroel are empolyed to estimate T m and η of ILs, see Eqs. and , respectively where is the contribution of group j to the melting point.…”

“…However, as demonstrated in our previous work, thermodynamic properties taking account both the practical separation condition and the effect of molecular weights of ILs (e.g., the distribution coefficient β and selectivity S derived from mass‐based liquid‐liquid equilibria (LLE) at a given relevant global composition) are more reasonable quantities for IL selection. Besides, some key physical properties, such as the melting point and viscosity, as well as the process performance of ILs should be evaluated carefully to find practically attractive IL solvents …”

Abraham model ion-specific equation coefficients for the 1-butyl-2,3-dimethyimidazolium and 4-cyano-1-butylpyridinium cations calculated from measured gas-to-liquid partition coefficient data

“…Considerable attention has been given in recent years towards developing mathematical expressions for estimating the physical properties and solubilising characteristics of IL solvents based on both group contribution methods and quantitative structure-property relationships. To date group contribution methods have been developed for predicting infinite dilution activity coefficients and gas-liquid partition coefficients of solutes dissolved in ILs, [1][2][3] for predicting enthalpies of solvation of organic solutes dissolved in ILs, [4] and for estimating viscosities, [5,6] thermal conductivities [7,8] isobaric heat capacities, [9][10][11] refractive indices, [12] static dielectric constants, [13] surface tensions, [14] densities, [15] and Daphnia magna water flea toxicities [16] of ILs at both 298 K and as a function of temperature.…”