Title: Ion transport properties of mechanically stable symmetric ABCBA pentablock copolymers with quaternary ammonium functionalized midblock

Abstract

Anion exchange membranes (AEMs) are a promising class of materials for applications that require selective ion transport, such as fuel cells, water purification, and electrolysis devices. Studies of structure–morphology–property relationships of ion-exchange membranes revealed that block copolymers exhibit improved ion conductivity and mechanical properties due to their microphase-separated morphologies with well-defined ionic domains. While most studies focused on symmetric diblock or triblock copolymers, here, the first example of a midblock quaternized pentablock AEM is presented. A symmetric ABCBA pentablock copolymer was functionalized to obtain a midblock brominated polymer. Solution cast films were then quaternized to obtain AEMs with resulting ion exchange capacities (IEC) ranging from 0.4 to 0.9 mmol/g. Despite the relatively low IEC, the polymers were highly conductive (up to 60 mS/cm Br2 at 90 8C and 95%RH) with low water absorption (<25 wt %) and maintained adequate mechanical properties in both dry and hydrated conditions. Xray scattering and transmission electron microscopy (TEM) revealed formation of cylindrical non-ionic domains in a connected ionic phase.

Authors:

Ertem, S. Piril ^[1]; Caire, Benjamin R. ^[2]; Tsai, Tsung-Han ^[1]; Zeng, Di ^[1]; Vandiver, Melissa A. ^[2]; Kusoglu, Ahmet ^[3]; Seifert, Soenke ^[3]; Hayward, Ryan C. ^[1]; Weber, Adam Z. ^[3]; Herring, Andrew M. ^[2]; Coughlin, E. Bryan ^[1]; Liberatore, Matthew W. ^[4]

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+ Show Author Affiliations

1. Department of Polymer Science and Engineering, University of Massachusetts Amherst, 120 Governors Drive Amherst Massachusetts 01003
2. Department of Chemical and Biological Engineering, Colorado School of Mines, Golden Colorado 80401
3. Energy Conversion Group, Energy Technologies Area, Lawrence Berkeley National Laboratory, Berkeley California 94720
4. Department of Chemical Engineering Department, University of Toledo, 2801 W Bancroft Street MS305 Toledo Ohio 43606

Publication Date:

2017-02-07

Research Org.:

Argonne National Lab. (ANL), Argonne, IL (United States)

Sponsoring Org.:

USDOE Office of Energy Efficiency and Renewable Energy (EERE); Argonne National Laboratory - Advanced Photon Source; US Army Research Office (ARO)

OSTI Identifier:

1395845

DOE Contract Number:  

AC02-06CH11357

Resource Type:

Journal Article

Journal Name:

Journal of Polymer Science. Part B, Polymer Physics

Additional Journal Information:

Journal Volume: 55; Journal Issue: 7; Journal ID: ISSN 0887-6266

Publisher:

Wiley

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; anion exchange membrane; block copolymers; conducting polymers; inverse morphology; ion conductivity; ionomers; mechanical properties; mechanically robust; morphology; pentablock copolymers