title: Validation of carrier-mediated transport of H(+) and Na(+) through mobile-site membranes.
abstract: The response of membranes containing neutral ion carriers of either H(+) or Na(+) to an externally-applied potential step was investigated using previously developed techniques for the analysis of charge and mass transport in ion-selective membranes. The results from constant-resistance membranes, e.g. membranes with unperturbed negative site concentration profiles, showed that tridodecylamine behaved as a carrier for H(+), and there was no evidence for proton hopping from stationary carriers. In addition, the experimental outcome supported the assumption of a failure of the Donnan exclusion principle at very low pH levels in these membranes. The results from membranes containing the Na(+) carrier illustrated the significant concentration polarization of ionic species, which was related to significant changes in bulk membrane resistance.
authors.affiliation: Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599-3290, U.S.A.
authors.forename: T M
authors.initials: TM
authors.lastname: Nahir
authors.forename: R P
authors.initials: RP
authors.lastname: Buck