A RAPID METHOD TO DETERMINE DIFFUSION COEFFICIENTS OF COUNTER-IONS IN AN ION-EXCHANGE MEMBRANE

摘要

A mathematical equation has been developed for the rapid and precise evaluation of interdiffusion coefficients of counter-ions in ion exchange membranes by Nernst-Planck equation with pseudosteady state assumption. The interdiffusion coefficients with various initial concentrations are determined by the experimental results reported by Sato et al. and Ho et al.. The diffusion coefficients of H~+, K~+ and Na~+ can be evalu- ated by regressing the profiles between interdiffusion coefficients and compositions in the membrane. Our results are in good agreement with those of Sato et al. and Ho et al. respectively, which reveals that our method for the calculation of diffusion coefficient is reasonable and practical.