Application of Raman spectroscopy to industrial membranes. Part 2-Perfluorosulphonic membrane

The Raman spectrum of a Nafion 117 membrane immersed in aqueous solution was recorded. Assignments are proposed for the fundamental vibrations observed for this material. The interaction of counter ions (cations) and also of sorbed electrolytes with the antagonist group SO3− of the membrane were studied. For this purpose, intensity measurements were made of selected appropriate signals versus the nature and type of counter ions (monovalent, divalent). The intensity of the symmetric stretching vibration band of the SO3− group can be used to monitor the variation of the conductivity of the membrane studied.