Viscous flow and electrical conductance in ionic liquids: Temperature and composition dependence in the light of the zero mobility concept

Using the concept of vanishing mobility consequent on the Gibbs-Dimarzio interpretation of the liquid-glass transition, it is shown by a quasiempirical treatment of the data that the isothermal composition dependence of transport at low temperatures may be understood, and expressed analytically, on the basis that the zero mobility temperature T₀, is the only composition-dependent parameter in the transport equation. To reflects the forces of cohesion in the liquid. Simple equations developed on this basis lead to a description of conductance in uni-divalent nitrate melts, and an account of viscous flow in 0-15N concentrated aqueous solutions which is consistent with the electrical-conductance behavior of the same solutions. The usefulness of the Tobolsky and related parameters in describing deviations from additivity in the conductance of mixed molten univalent nitrates is interpreted in the same terms, providing a rational basis for the parallel between kinetic and thermodynamic behavior in these melts. Attention is drawn to the importance of pre-exponential terms to transport composition dependence at higher temperatures.