Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Koizumi, Satoshi; Putra, A.; Noda, Yohei; Yamaguchi, Daisuke; Tokumasu, Takashi*; Kawakatsu, Toshihiro*
no journal, ,
In order to perform a multi-scale observation on a membrane-electrolyte assembly (MEA) of polymer electrolyte fuel cell (PEFC), small-angle neutron scattering (SANS) was recently reinforced by advanced neutron optics. A focusing ultra-small-angle scattering method was developed by using a neutron lens. By combining a double crystal (Bonse-Hart) method, we are able to reach to 10 micron meter length scale, which corresponds to the size of aggregation by carbon powders in an electrode layer. Polarization analysis enables us to selectively remove incoherent scattering from hydrogen atoms and to detect coherent scattering due to ion-cluster of polymer electrolyte (Nafion) and water distribution in it. In order to output structural information in real space, we examined our SANS results by comparing images in real space obtained by low vacuum SEM and multi-scale computer simulations.
Koizumi, Satoshi; Kawakatsu, Toshihiro*; Tokumasu, Takashi*
no journal, ,
no abstracts in English
Koizumi, Satoshi; Rikukawa, Masahiro*; Yoshida, Miru*; Tokumasu, Takashi*; Zhao, Y.; Maekawa, Yasunari
no journal, ,
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 (H
O/DO) and the swollen microdomain. In this talk, we present the understandings on the morphology and water distributions in these membranes.