Experimental densities and viscosities of binary mixture of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide or glycerol with sulfolane and their molecular interaction by COSMO-RS

Highlights: •Densities and viscosities were measured for binary mixtures [BMIM][NTf₂] + sulfolane and glycerol + sulfolane. •Derived properties were calculated from measured densities and viscosities. •Redlich-Kister polynomial was used to fit the results. •Thermodynamic value calculated using the Eyring's equation. •Interactions between the binary components were evaluated using COSMO-RS model. -- Abstract: Thermophysical properties of solvent are set of data that are essential for designing processes in industry. But in the absence of experimental data, an accurate predictive method is required. In this context, density (ρ) and viscosity (η) of sulfolane with glycerol and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide have been measured over the entire range of composition with temperature ranging from 298.15 K to 363.15 K at atmospheric pressure. From these experimental values, thermal expansion (α), excess molar volume (V^E), viscosity deviation (Δη) and Gibbs free energy (ΔG) were calculated. The predicted values were close to the corresponding experimental data with all the standard deviation lower than 1 × 10⁻³. Quantum chemical based COSMO-RS was used to predict the molecular interaction and non-ideal liquid phase activity coefficient for all mixtures. It has been interpreted that strong interaction for the sulfolane + [BMIM][NTf₂] system, meanwhile weak interaction was deduced for the sulfolane + glycerol system. The molar enthalpy (ΔH), entropy (ΔS) and Gibbs free energy of activation (ΔG) of viscosity were calculated. Simultaneous effects of composition and temperature for the binary mixtures were also reported.