A group contribution model for prediction of the viscosity with temperature dependency for fluorine-containing ionic liquids

Abstract

Abstract One of the barriers against application of ionic liquids (ILs) for industrial separations is their relatively high viscosity. The viscosity of the IL can however be decreased by inserting the fluorinated moieties into the anion structure. Hence, if one could find a relationship between chemical structure, temperature, and viscosity one could design fluorine-containing ILs (F-ILs) with desired specifications. In this communication, two extensive dataset of F-ILs were gathered; one with reliable sources consisting of 863 experimental viscosities for 85 F-ILs, and the other including unreliable sources consisting of 1160 experimental data points for 332 F-ILs. Using the reliable dataset an efficient group contribution (GC) model was developed, which employs a total of 35 functional groups to estimate the temperature-dependent viscosities of F-ILs. The proposed GC model produced a low average absolute relative deviation (AARD) of 3.23%, root-mean-square error (RMSE) of 0.19, and coefficient of determination (R 2 ) of 0.977. The other model developed using the second database only parameterized in supplementary materials.