CURRENT-VOLTAGE CURVES FOR ION-EXCHANGE MEMBRANES - A METHOD FOR DETERMINING THE LIMITING CURRENT-DENSITY

The curves (V, I) of different ion-exchange membranes have been determ ined under different experimental conditions. Taking into account the classical theory of concentration polarization, a method has been deve loped to adjust the (V, I) data, up to a certain value of I, which per mits us to obtain easily the value of the limiting current density, I- L, in every experimental situation. From these values, the dependence of the limiting current density of the membranes used on the concentra tion and stirring rate of the solutions has been studied. To check the reliability of the method, the values of I-L thus obtained have been compared with those obtained by the usual methods; the similitude betw een both values is high. (C) 1998 Academic Press.