INFRARED INVESTIGATIONS ON PERFLUOROSULFONATE (NAFION-117) MEMBRANES IN THE H+, LI+, CS+ AND TETRAMETHYL AMMONIUM [N(CH(3)4(+)] IONIC FORMS

Infrared investigations on H+, Li+, Cs+ and N(CH3)4+ ionic forms of th e perfluorosulphonate exchanger membrane, Nafion-117, in dry, H2O-wet and D2O-wet conditions have been carried out by transmission and ATR t echniques. Correct interpretation of splitting of the 980 cm-1 band an d the shift, of the 1056 cm-1 band on drying have been given in terms of relative hydration and the electron withdrawal (from -SO3-) by bare cations, respectively. Spectra in the OH and OD stretching regions ha ve been interpreted taking into account the interaction between fluoro carbon network, hydrophobic interaction [for N(CH3)4+] and sulphonate group hydration.