title: Membrane potential across reverse osmosis membranes under pressure gradient.
abstract: Membrane potential measurement has been widely used for the characterization of ionic membranes such as ion-exchange membranes without solvent permeability. However, there have been few studies on membrane potentials across pressure-driven processes such as reverse osmosis (RO) membranes with solvent permeability. In the present study, the membrane potential across RO membranes in NaCl and MgCl2 under the pressure gradient, DeltaP=0-0.3 MPa, was measured. The experimental results were analyzed by the theoretical model based on the Donnan equilibrium and the extended Nernst-Planck flux equation considering the pressure effect. The theoretical values agreed well with the experimental ones. This indicates that membrane potential is useful for characterizing the effective charge density of the active layer of RO membranes under pressure gradient.
authors.affiliation: Department of Organic and Polymeric Materials, and International Research Center of Macromolecular Science, Tokyo Institute of Technology, Mail Box S8-27, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552, Japan.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Matsumoto
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Konosu
authors.forename: Naomichi
authors.initials: N
authors.lastname: Kimura
authors.forename: Mie
authors.initials: M
authors.lastname: Minagawa
authors.forename: Akihiko
authors.initials: A
authors.lastname: Tanioka