New approach to characterization of hybrid nanocomposites

Abstract

This paper presents a novel approach to the characterization of hybrid cation-exchange membranes by applying the “fine porous membrane” model. We verify this approach using samples of cation-exchange membranes synthesized on the base of the perfluorinated MF-4SC membrane and halloysite nanotubes and prepared by the casting method. For characterization we use the initial pure MF-4SC membrane and two hybrid membranes MF-4SC spatially modified with halloysite nanotubes encapsulated by Pt nanoparticles or intercalated by Fe nanoparticles. Based on our own experimental data for the diffusion permeability and specific conductivity in dependence on electrolyte concentration (HCl), we calculate the main physico-chemical parameters of these membrane systems, i.e. the ambipolar diffusion and equilibrium distribution coefficients of the electrolyte inside the membrane. Comparing the theoretically calculated parameters to the experimentally measured current-voltage curves, selectivity, transport numbers of cations and water for all the three samples we conclude that the hybrid membrane with platinum nanoparticles is superior to the other two membranes as far as fuel cells are concerned.