title: Mechanoassisted Synthesis of Sulfonated Covalent Organic Frameworks with High Intrinsic Proton Conductivity.
abstract: It is challenging to introduce pendent sulfonic acid groups into modularly built crystalline porous frameworks for intrinsic proton conduction. Herein, we report the mechanoassisted synthesis of two sulfonated covalent organic frameworks (COFs) possessing one-dimensional nanoporous channels decorated with pendent sulfonic acid groups. These COFs exhibit high intrinsic proton conductivity as high as 3.96 × 10(-2) S cm(-1) with long-term stability at ambient temperature and 97% relative humidity (RH). In addition, they were blended with nonconductive polyvinylidene fluoride (PVDF) affording a series of mixed-matrix membranes (MMMs) with proton conductivity up to 1.58 × 10(-2) S cm(-1) and low activation energy of 0.21 eV suggesting the Grotthuss mechanism for proton conduction. Our study has demonstrated the high intrinsic proton conductivity of COFs shedding lights on their wide applications in proton exchange membranes.
authors.affiliation: Department of Chemical & Biomolecular Engineering, National University of Singapore , 4 Engineering Drive 4, 117585 Singapore.
authors.forename: Yongwu
authors.initials: Y
authors.lastname: Peng
authors.affiliation: Sustainable Energy Laboratory, Faculty of Materials Science and Chemistry, University of Geosciences Wuhan , 388 Lumo RD, Wuhan, 430074 China.
authors.forename: Guodong
authors.initials: G
authors.lastname: Xu
authors.affiliation: Department of Chemical & Biomolecular Engineering, National University of Singapore , 4 Engineering Drive 4, 117585 Singapore.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Hu
authors.affiliation: Department of Chemical & Biomolecular Engineering, National University of Singapore , 4 Engineering Drive 4, 117585 Singapore.
authors.forename: Youdong
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: Department of Chemical & Biomolecular Engineering, National University of Singapore , 4 Engineering Drive 4, 117585 Singapore.
authors.forename: Chenglong
authors.initials: C
authors.lastname: Chi
authors.affiliation: State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences , Fuzhou, 350002 China.
authors.forename: Daqiang
authors.initials: D
authors.lastname: Yuan
authors.affiliation: Sustainable Energy Laboratory, Faculty of Materials Science and Chemistry, University of Geosciences Wuhan , 388 Lumo RD, Wuhan, 430074 China.
authors.forename: Hansong
authors.initials: H
authors.lastname: Cheng
authors.affiliation: Department of Chemical & Biomolecular Engineering, National University of Singapore , 4 Engineering Drive 4, 117585 Singapore.
authors.forename: Dan
authors.initials: D
authors.lastname: Zhao
keywords: covalent organic frameworks; mechanoassisted synthesis; mixed matrix membranes; proton conductivity; proton exchange membranes