Characterization of polymer electrolyte Nafion membranes: Influence of temperature, heat treatment and drying protocol on sorption and transport properties

► We performed sorption and transport measurements in Nafion 115 and 212. ► We provide the community with a comprehensive set of experimental data. ► If the membrane is dried its water uptake decreases due to shrinkage of its structure. ► The proton conductivity and water self-diffusion coefficient are also reduced. ► The water uptake of Nafion 115 and 212 decreases with the measuring temperature.