6533b837fe1ef96bd12a26b6

RESEARCH PRODUCT

Conductive and Capacitive Properties of the Bipolar Membrane Junction Studied by AC Impedance Spectroscopy

Patricio RamirezJosé A. Manzanares AndSalvador MafeAntonio Alcaraz

subject

business.industryChemistryCapacitive sensingAntenna apertureAnalytical chemistryIonic bondingDissociation (chemistry)Surfaces Coatings and FilmsMembraneAc impedance spectroscopyMaterials ChemistryOptoelectronicsPhysical and Theoretical ChemistryElectric currentbusinessElectrical conductor

description

The complete ac impedance spectrum of four bipolar membranes is analyzed both theoretically and experimentally taking into account both ionic transport and water dissociation together with the structural aspects of the bipolar junction. A theoretical model based on the Nernst-Planck and Poisson equations for the conductive and capacitive properties of the junction provides a qualitative description of the bipolar membranes for a broad range of electric currents and temperatures. Special attention is paid to the characteristics of the bipolar junction structure and the contact region between the two ion-exchange layers. It is observed that the effective area of this region increases with the electric current as mobile carriers are extracted from the interface and the layers come in closer contact.

https://doi.org/10.1021/jp011581x