Low-frequency dynamics of water absorbed in Nafion membranes as a function of temperature

Recent developments in proton exchange membranes for fuel cells

“…The structure, proton and small molecule transport processes and mechanical properties of Nafion have been studied extensively by experiment. Neutron and X-ray scattering, 9,19,[31][32][33][34][35][36][37][38][39][40] nuclear magnetic resonance (NMR), [41][42][43][44] infrared (IR) spectroscopy, [45][46][47][48][49] electron and atomic force microscopy, 31,50,51 differential scanning calorimetry, 52 dielectric relaxation spectroscopy, 53,54 alternating current (ac) impedance spectroscopy, 35,39,40,51 dynamic mechanical analysis 11 and electron spin resonance spectroscopy 55 are among the many techniques that have been used to characterize membrane materials.…”

“…In fact, proton transport in Nafion by the Grotthuss mechanism is supported by simulation studies discussed in the next subsection. The differences between QENS studies of Nafion 35,[37][38][39] may arise from the use of different models to interpret the data, and differences in energy resolution and membrane thickness. This is especially significant in light of the finding of Kim et al 59 that membrane processing, thermal history and thickness influence the morphology and by extension the transport properties.…”