Composite Nafion-based membranes with nanosized tungsten oxides prepared in supercritical carbon dioxide

A novel method for introduction of tungsten oxide nanoparticles into a Nafion membrane following the infiltration concept is presented. Non-polar supercritical carbon dioxide is used as a solvent for impregnation of tungsten metalorganic precursor into phase-separated polymer structure. Uniformly distributed 2–4 nm particles of tungsten oxides are obtained. This size coincides with the typical diameter of hydrophilic channels in Nafion. Larger...