Extended x-ray absorption fine structure: Studies of zinc-neutralized sulfonated polystyrene ionomers

Abstract

Extended x-ray absorption fine structure (EXAFS) measurements were performed on a series of zinc-neutralized sulfonated polystyrene ionomers and the local structure around the zinc atom was determined. An interference effect in the EXAFS signal between sulfur and oxygen atoms was found to be significant in these materials. A model for the local structure in the zinc-neutralized sulfonated polystyrene ionomers is proposed which suggests a highly ordered tetrahedral coordination of oxygen around the zinc atoms at a distance of 1.97±0.02 Å. In addition there are four sulfur atoms and four oxygen atoms at a distance of 3.15±0.05 Å. No zinc-zinc coordination within 5 Å was detected in this study.