Pulsed field gradient (PFG) NMR in combination with quasielastic neutron scattering (QENS) was used to investigate self-diffusion of water and acetone in Nafion membranes with and without immobilized vanillic acid...

Pulsed field gradient (PFG) NMR at high magnetic field was used to study microscopic diffusion of dimethyl methyl phosphonate (DMMP), a common chemical warfare agent (CWA) simulant, and water in Nafion membranes. PFG NMR measurements were performed for a broad range of molecular displacements. The self‐diffusivities were measured as a function of the DMMP concentration for several fixed water concentrations. The measured data suggest that DMMP and water diffuse in different regions of Nafion. While water mostly diffuses in hydrophilic regions of the membrane, viz. water channels, DMMP diffusion is mostly limited to interfacial perfluoroether regions between these water channels and the semi‐crystalline matrix.