Bipolar membranes consist of a layered ionhyphen;exchange structure composed of a cation selective membrane joined to an anion selective membrane. They are analogous to semiconductorphyphen;ndevices as both of them present currenthyphen;voltage curves exhibiting similar rectification properties. In this article, we present some currenthyphen;voltage curves obtained for different bipolar membranes at several temperatures. The results can be interpreted in terms of a simple model for ion transport and fieldhyphen;enhanced water dissociation previously developed. The mechanism responsible for water splitting is assumed to be a catalytic proton transfer reaction between the charged groups and the water at the membrane interface. The effects of temperature are taken into account by introducing an Arrheniushyphen;type relationship for the dependence of the forward rate constant of the reaction on temperature. Finally, comparison between theory and experiments provides reasonable values for the parameters introduced in the theoretical model. The analysis aims at developing a better physical understanding of a process in which chemical reactions and transport phenomena are coupled in such a way that the potential technological applications depend strongly on this coupling.
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