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

The viscosity of ionic liquids at different temperatures was estimated with a simple group contribution method. The proposed method was applied using an Andrade-type approach. Experimental data of 183 ionic liquids (1110 data points) with viscosity in a range of 6 to 20,883 (cP) at temperatures in a range of 253 K to 395 K were used to obtain the contributions for the cation-anion groups in a correlation set. Then, the viscosities of another 143 ionic liquids (335 data points) were predicted, and the results were compared with experimental data available in the literature. The results show that this group contribution method represents an excellent alternative for the estimation of the viscosity of diverse ionic liquids at different temperatures from the knowledge of their molecular structure with an average deviation of 4.5% and a correlation coefficient of 0.94.