Impact of chemical treatments on the behavior of water in Nafion® NRE-212 by 1H NMR: Self-diffusion measurements and proton quantization

► Water diffusion is the same for Nafion in Na+ and K+ forms for a given water content. ► At a given water content, diffusion is faster in the acid form as compared with diffusion in sodium or potassium forms. ► The amount of protons within Nafion in acid form by NMR is higher than that by weighing method. ► The lability of water in the acid form is more effective than in sodium or potassium form. ► A specific behavior of water surrounding each counter-cation is clearly observed by 1H NMR.