Dergiler / Turkish Journal of Engineering and Environmental Sciences / 2009 / Cilt: 33 - Sayı: 1

Membrane potentials for linearly varying fixed charges

Sayfa
73–81
DOI
—

Özet

The membrane potentials for asymmetric membranes where fixed charges varied linearly with position were evaluated from the numerical solutions of Nernst-Planck flux and Donnan potential equations. The evaluated membrane potentials were compared with the results obtained from the conventional TMS theory where the fixed charge concentration in the membrane was assumed to be uniform. In the comparison, the number of fixed charges was kept constant by defining an average for the fixed charge concentration. The numerical results showed that the membrane potential increased in magnitude when the distributions of fixed charges at the membrane-solution interfaces were unequal. In addition, the deviation from TMS theory increased more as the charge difference at the interfaces increased.

Abstract

The membrane potentials for asymmetric membranes where fixed charges varied linearly with position were evaluated from the numerical solutions of Nernst-Planck flux and Donnan potential equations. The evaluated membrane potentials were compared with the results obtained from the conventional TMS theory where the fixed charge concentration in the membrane was assumed to be uniform. In the comparison, the number of fixed charges was kept constant by defining an average for the fixed charge concentration. The numerical results showed that the membrane potential increased in magnitude when the distributions of fixed charges at the membrane-solution interfaces were unequal. In addition, the deviation from TMS theory increased more as the charge difference at the interfaces increased.

Anahtar kelimeler: Membrane potential; Donnan potential; Charged membranes; TMS theory; Surface charges; Fixed charge concentration.