Anomalous small-angle x-ray scattering from a sulfonated polystyrene ionomer

Anomalous small-angle X-ray scattering has been employed to study the morphology of a Ni-neutralized sulfonated polystyrene ionomer, with particular emphasis on the characteristic upturn in scattered intensity near zero angle. The results indicate that the zero-order scattering is related to the ionomer's neutralizing cation. Applying the Debye--Bueche random two-phase model to the data indicates that the heterogeneity giving rise to the zero-angle scattering has a much larger length scale and smaller electron density difference than the aggregate--matrix scattering and may be due to an inhomogeneous distribution of isolated ionic groups in the matrix. 39 ref.--AA