Viscosity of binary mixtures of 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid with four organic solvents

•Viscosities of four binary mixtures of [Emim][BF4] with organic solvents.•Viscosity models based on Eyring’s theory.•Excess functions calculated.•Data for binaries new in the literature, except for system with DMSO.

This paper reports experimental values of dynamic viscosity for four binary systems of 1-ethyl-3-methylimidazolium tetrafluoroborate, [Emim][BF4], with dimethyl sulfoxide (DMSO), acetonitrile (ACN), ethylene glycol (EG) and 1,4-dioxane over the temperature ranges from 293.15 K to 353.15 K at p = 0.1 MPa. All binary mixtures were completely miscible over the entire range of mole fraction, except the system with 1,4-dioxane. The viscosity results have been correlated by the one parameter Grunberg–Nissan and Fang and He equations and the two-parameter McAllister, Eyring-UNIQUAC, Eyring-NRTL and Eyring-Wilson models and the results were compared.Additionally, the viscosity deviations, Δη, and the excess Gibbs energy of activation for viscous flow, G∗E, were calculated and fitted to the Redlich–Kister equation. The results show that all Δη values are negative over the whole composition range and the G∗E values are positive, except for the system with EG. The results of the excess functions are discussed in terms of molecular interactions.