Viscosity Modeling of Pure Ionic Liquids and Their Binary Mixtures Using a Modified Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) Equation of State and Entropy Scaling

Ionic liquids (ILs) have garnered significant interest
due to their
unique physicochemical properties and promising application potential.
Among these properties, viscosity plays a critical role in determining
IL performance. In this study, the entropy scaling method in combination
with the perturbed-chain statistical associating fluid theory (PC-SAFT)
equation of state (EoS) is employed to build a correlational model
for pure ILs and a predictive model for IL binary mixtures. Model
parameters for the PC-SAFT EoS were regressed against a comprehensive
experimental data set comprising 12,239 density data points. A complete
set of PC-SAFT molecular parameters for 45 ILs is reported. For 31
pure ILs, covering temperatures from 259.50 to 438.15 K and pressures
from 0.6 to 4011.0 bar, the model achieves an average absolute relative
deviation (AARD) of 7.72%. For 9 IL binary mixtures at atmospheric
pressure, with temperatures ranging from 253.15 to 363.15 K, the AARD
is 14.20%.