Electric impedance of cellulose acetate membranes and a composite membrane at different salt concentrations

Theoretical and Experimental Study of the Voltage–Current Characteristic of an Asymmetric Cellulose Acetate Membrane

“…Our analysis of the small-current resistance indicates that the contribution of the nonselective layer to the membrane resistance is rather small, which is in agreement with earlier find-ings (28,29). With the membrane parameters (C*, D 1s , D 2s ) obtained from the above fit procedure for several values of l s in the range 2 ϫ 10 Ϫ6 to 10 Ϫ5 cm, it was found that the contribution of the resistance of the support layer to the total membrane resistance is equal to 4% at 0.005 M NaCl and 1% at 0.05 M NaCl.…”

Electrochemical Characterization of an Asymmetric Nanofiltration Membrane with NaCl and KCl Solutions: Influence of Membrane Asymmetry on Transport Parameters

“…The thickness of the dense layer ( x d ) can be estimated from C dl values, assuming this layer behaves as a plate capacitor (11,23):…”

“…It is being used as a successful tool to determine the electrical properties of heterogeneous systems formed by a series array of layers with different electrical/ structural properties such as symmetric membrane/electrolyte or even composite membrane/electrolyte systems since it permits us to evaluate separately the electrical contribution of each sublayer (10)(11)(12)(13). IS measurements enable us to obtain information about systems by using the impedance plots and the equivalent circuits as models, where the different circuit elements are related to the structural/transport properties of the systems.…”

Electroosmosis through a Cation-Exchange Membrane: Effect of an ac Perturbation on the Electroosmotic Flow

“…In fact, consideration of the membrane-or heterogeneous media in general-from a point of view of their dielectric properties has been used from some time ago. In this sense, the membrane is basically considered as a leaky capacitor, and different electric circuits have been presented to establish an electric analogy to describe the system in terms of impedance measurements (13)(14)(15). The functional properties of membranes and solid-aqueous systems, in general, are closely connected to the electrochemical processes that occur within the interfacial regions between the membrane surface and the bulk electrolyte.…”