Transport Properties of MF-4SK Membranes Doped with Sulfonated Zirconia

Composite materials based on homogeneous perfluorinated MF-4SK cation-exchange membranes and sulfonated zirconia are obtained by in situ and casting methods. Their transport properties and gas-permeability are studied. The introduction of sulfonated zirconia leads to increase the room-temperature conductivity of membranes obtained by the in situ and casting methods more than 1.5- and 4-fold, respectively. For composite membranes synthesized by the in situ and casting methods, the transport numbers of anions that characterize their undesired transport decrease more than 1.5-fold (from 0.026 to 0.020 and from 0.020 to 0.014, respectively). For samples based on MF-4SK membranes and zirconia, the considerable (more than 3-fold) decrease in hydrogen permeability is observed. The differences in the observed values of water uptake, conductivity, and interdiffusion coefficients in composite membranes are discussed.