Abstract
Neutron reflectivity (NR) is being used to measure simulated long-term behavior of idealized electrode interfacial structures in varying humidity environments. Nafion® ionomer dispersions were examined after deposition onto glassy carbon (GC) substrates before and after accelerated testing, and significant changes in the oxide content of GC and scattering length density of Nafion® were observed. Single layers of Nafion® and Nafion®/Pt bilayers on GC have also been investigated. Data was obtained for these samples with Nafion® 1100-EW films equilibrated in three different water vapor relative humidity (RH) environments - ambient ~10% H2O, 10% D2O, and 100% D2O. This data shows that a multilayer, in-situ NR model is needed to describe thin Nafion films when equilibrated with water vapor and is discussed in context of its implications on the oxygen reduction reaction and Pt-Nafion microelectrode studies.