Diffusion coefficients and conductivities of alkylimidazolium tetrafluoroborates and hexafluorophosphates

Abstract

In this study, diffusion coefficients of alkylimidazolium tetrafluoroborates and hexafluorophosphates ionic liquids in water at room temperature were measured by the Taylor dispersion experiment. The Wilke-Chang equation underestimated the diffusion coefficient, but a modified Wilke-Chang equation correlated diffusion coefficients well with molar volumes. The conductivities of these ion liquids were also measured. Infinite dilute conductances were calculated. The Nernst-Haskell equation accurately estimated diffusion coefficients using the infinite dilute conductance obtained. © 2007 Elsevier B.V. All rights reserved.