Water Dynamics in Ionomer Membranes by Field‐Cycling NMR Relaxometry

Abstract

Abstract The water dynamics of two types of ionomer membranes, the Nafion ® and sulfonated polyimides, have been investigated by field‐cycling nuclear magnetic relaxation. This technique, applied to samples prepared at different water content, allows to characterize the proton motion at the time scale of the microsecond. The polyimides appear to behave as standard porous materials, whereas in the Nafion ® , we have observed two different dynamical regimes related to a complex swelling process.