Viscosity of Typical Room-Temperature Ionic Liquids: A Critical Review

Experimental data on viscosity of typical ionic liquids in the liquid state were compiled and critically evaluated. The compilation contains data for 268 ionic liquids from 215 literature references and covers the period from 1998 through the end of December 2018. Equations for corrections of influences of contamination water and residual Cl- on viscosities of a series of typical ionic liquids are established. The influences of experimental methodology and the impurities (i.e., contamination water and residual halide ions) of the samples used on the reported viscosities of these typical ionic liquids are critically evaluated or quantitatively corrected, and the viscosities for these "pure" ionic liquids are recommended. The parameters of the Vogel-Fulcher-Tammann equation for temperature dependence of the recommended viscosities of these ionic liquids were reported. The effects of ionic structures on the viscosity of ionic liquids are presented.