FTIR spectroscopic study of the interaction between NH4+ and DMSO in Nafion.

Nafion-NH4+ membranes plasticized with dimethyl sulfoxide (DMSO and DMSO-d6) have been investigated at room temperature using the vacuum ATR-FTIR and FTIR absorption spectroscopic technique in the range 50-4000 cm-1. The amount of the plasticizer corresponds to the molecular ratio n = DMSO/NH4+ = 2.7-13.8. The mutual association of free DMSO molecules in Nafion leads to appearance of weak band at 86 cm-1 assigned to dipole-dipole interactions. Also the Raman spectra of dry Nafion-NH4+ membranes were investigated.