Quantitative video-rate hydration imaging of Nafion® proton exchange membranes with THz radiation

Nafion® polymeric membranes are the prime electrolyte material for proton exchange membrane fuel cells (PEMFC), requiring adequate hydration in order to reach high proton conductivity. The relatively high attenuation of terahertz (THz) radiation of liquid water compared to the surrounding polymer assembly enables a contrast to be observed for inspecting water build-up in Nafion® membranes. This paper investigates the feasibility of a compact THz camera for liquid water mapping and quantification in Nafion® polymeric membrane.