Structural analysis on hydrocarbon polymer electrolyte membrane by solvent contrast variation small-angle neutron scattering

Koizumi, Satoshi; Rikukawa, Masahiro*; Yoshida, Miru*; Tokumasu, Takashi*; Zhao, Y.; Maekawa, Yasunari

We employed contrast variation small-angle neutron scattering method to investigate the morphologies of a newly designed polymer electrolyte membrane, made of multi-block copolymer poly(sulphonate phenylene)-b-poly(arylene ether ketone), which is coded as S-6H (n) x:y where x:y denote a ration between hydrophilic and hydrophobic block components. Two scattering maximums were observed at low q and high q regions for wet membranes, where q is a magnitude of scattering vector. The low q maximum is attributed to formation of microdomain upon swelling, whereas the high q maximum is due to the ion clusters in a swollen microdomain. The morphology could be stressed by the contrast variation method, which results in matching in scattering contrast between mixed water (HO/DO) and the swollen microdomain. In this talk, we present the understandings on the morphology and water distributions in these membranes.