title: Controlling Microstructure-Transport Interplay in Highly Phase-Separated Perfluorosulfonated Aromatic Multiblock Ionomers via Molecular Architecture Design.
abstract: Proton-conducting multiblock polysulfones bearing perfluorosulfonic acid side chains were designed to encode nanoscale phase-separation, well-defined hydrophilic/hydrophobic interfaces, and optimized transport properties. Herein, we show that the superacid side chains yield highly ordered morphologies that can be tailored by best compromising ion-exchange capacity and block lengths. The obtained microstructures were extensively characterized by small-angle neutron scattering (SANS) over an extended range of hydration. Peculiar swelling behaviors were evidenced at two different scales and attributed to the dilution of locally flat polymer particles. We evidence the direct correlation between the quality of interfaces, the topology and connectivity of ionic nanodomains, the block superstructure long-range organization, and the transport properties. In particular, we found that the proton conductivity linearly depends on the microscopic expansion of both ionic and block domains. These findings indicate that neat nanoscale phase-separation and block-induced long-range connectivity can be optimized by designing aromatic ionomers with controlled architectures to improve the performances of polymer electrolyte membranes.
authors.affiliation: LEPMI, Université Grenoble Alpes - CNRS , 38000 Grenoble, France.
authors.forename: Huu-Dat
authors.initials: HD
authors.lastname: Nguyen
authors.affiliation: LEPMI, Université Grenoble Alpes - CNRS , 38000 Grenoble, France.
authors.forename: Luca
authors.initials: L
authors.lastname: Assumma
authors.affiliation: Laboratoire Léon Brillouin (LLB), CNRS-CEA, Université Paris-Saclay, CEA Saclay , 91191 Gif-sur-Yvette Cedex, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Judeinstein
authors.affiliation: Ingénierie des Matériaux Polymères, Université de Lyon , 69622 Villeurbanne, France.
authors.forename: Regis
authors.initials: R
authors.lastname: Mercier
authors.affiliation: Institut Laue Langevin (ILL) , 38002 Grenoble, France.
authors.forename: Lionel
authors.initials: L
authors.lastname: Porcar
authors.affiliation: Laboratoire Léon Brillouin (LLB), CNRS-CEA, Université Paris-Saclay, CEA Saclay , 91191 Gif-sur-Yvette Cedex, France.
authors.forename: Jacques
authors.initials: J
authors.lastname: Jestin
authors.affiliation: LEPMI, Université Grenoble Alpes - CNRS , 38000 Grenoble, France.
authors.forename: Cristina
authors.initials: C
authors.lastname: Iojoiu
authors.affiliation: INAC-SPrAM, Université Grenoble Alpes - CEA - CNRS , 38000 Grenoble, France.
authors.forename: Sandrine
authors.identifier: http://orcid.org/0000-0003-2580-8439
authors.initials: S
authors.lastname: Lyonnard
keywords: PEMFCs; block copolymers; ionic/nonionic interfaces; phase-separated structures; proton-exchange membranes