Evaluated the transference numbers of four vanadium cations through positively, negatively, and initially uncharged membranes. Complete data sets collected including conductivity, transference number, and sorption.
Significance and Impact
Measured transference numbers show good agreement with predictions from Nernst-Planck-Einstein for cation-exchange membranes. Large deviations are observed in anion-exchange membranes indicating that concentrated-solution theory is required to describe transport of active materials through these systems.
Transference numbers measured by collecting active species crossing through test membranes as a function of current density. Conductivity measured with four-point probe. Sorption measured by ion exchange.
- Measured and predicted transference numbers in good agreement for cation-exchange membranes, but not anion-exchange membranes.