%0 Journal Article
%A Auffarth, Sebastian
%A Wagner, Maximilian
%A Krieger, Anja
%A Fritsch, Birk
%A Hager, Linus
%A Hutzler, Andreas
%A Böhm, Thomas
%A Thiele, Simon
%A Kerres, Jochen
%T Nanophase-Separated Block-co-Polymers Based on Phosphonated Pentafluorostyrene and Octylstyrene for Proton-Exchange Membranes
%J ACS materials letters
%V 5
%@ 2639-4979
%C Washington, DC
%I ACS Publications
%M FZJ-2023-02545
%P 2039 - 2046
%D 2023
%X Nanophase separation into hydrophobic and hydrophilic domains in commercial perfluorosulfonic acid polymers promotes high conductivity by forming proton-conductive channels within a matrix. To transfer this beneficial phase separation to phosphonic acid functionalized ionomers, we combine phosphonated polypentafluorostyrene and flexible polyoctylstyrene in a di-block-co-polymer. We introduce a stepwise approach, including mesophase simulations, synthesis, and spectroscopic imaging. After the required block lengths were calculated, controlled radical polymerization led to a narrowly distributed block-co-polymer. The respective block-co-polymer membrane outperforms a phosphonated pentafluorostyrene blend concerning conductivity and water uptake. Stained membrane cross-sections revealed bicontinuous nanophase separation in the 13 to 25 nm range in transmission electron microscopy. The ion-conducting phosphonated polymer block assembled into an isotropic, three-dimensional gyroidal network across the membrane. Our stepwise approach is transferable toward other block-co-polymer systems featuring different monomers or functional groups. Applying the proposed principles allows for the prediction of structure-related phase separation while reducing the amount of synthesis work.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:001016545300001
%R 10.1021/acsmaterialslett.3c00569
%U https://juser.fz-juelich.de/record/1008906