TRANSPORT OF PROTONS AND WATER THROUGH POLYANILINE MEMBRANES STUDIED WITH ONLINE MASS-SPECTROMETRY

The hydrogen evolution reaction (HER) was followed during the polymeri zation of aniline on porous platinum electrodes by means of cyclic vol tammetry combined with on-line mass spectrometry. It was found that th e reaction takes place at the electrode/polymer interface by consideri ng the collection efficiency of the membrane inlet system. It is demon strated that homogeneous films of polyaniline (PANI) can be deposited onto porous electrode substrates. In this way, a pervaporation membran e is formed with the conducting polymer as the active layer. The perme ation of water through a PANI membrane is dependent on the oxidation s tate of PANI. The higher permeability in the oxidized state is explain ed in terms of structural alterations during the redox process.