Title: Poly(norbornene) anion conductive membranes: homopolymer, block copolymer and random copolymer properties and performance

Abstract

It has previously been shown that phase-separated block copolymers with non-ion conducting (hydrophobic) blocks and ion conducting (hydrophilic) blocks can form efficient ion conducting channels with high ionic mobility and conductivity. Block copolymers can provide a means for phase segregation and ion channel formation while homopolymers and random copolymers have been shown to have lower ion mobility. In this study, the properties of poly(norbornene) based anion exchange membranes (AEMs) comprising homopolymers, block copolymers, and random copolymers with high ion-exchange capacity (IEC) (3.48–4.55 meq. g^-1) have been investigated and compared. The polymers were cross-linked with N,N,N',N'-tetramethyl-1,6-hexanediamine before casting the membranes to avoid excessive water swelling due to high water uptake. It was shown that high ionic conductivity can be achieved in both random copolymers and homopolymers even in the absence of microphase-separated structures. For example, the conductivity of a random copolymer was 194 mS cm^-1 at 80 °C, which was comparable to the block copolymer, 201 mS cm^-1 at 80 °C. The H₂/O₂ fuel cell performance of random copolymer composite membranes showed a peak power density of 3.05 W cm^-2 and peak current density of 7.85 A cm^-2 at 80 °C compared to block copolymer membranes (peak power density of 3.21more » W cm^-2 and peak current density of 8.27 A cm^-2 at 80 °C). It is more critical that high water transport be achieved in AEMs than achieving a phase-segregated morphology. Finally, the homopolymer, block copolymer, and random copolymer membranes showed <1.35% degradation after aging in 1 M NaOH at 80 °C for 1000 h.« less

Authors:

Mandal, Mrinmay  ^[1];

• Search DOE PAGES for author "Mandal, Mrinmay"
• Search DOE PAGES for ORCID "0000-0002-3404-9588"

Huang, Garrett  ^[1];

• Search DOE PAGES for author "Huang, Garrett"
• Search DOE PAGES for ORCID "0000-0003-0100-4161"

Hassan, Noor Ul ^[2]; Mustain, William E.  ^[2];

• Search DOE PAGES for author "Mustain, William E."
• Search DOE PAGES for ORCID "0000-0001-7804-6410"

Kohl, Paul A.  ^[1]

• Search DOE PAGES for author "Kohl, Paul A."
• Search DOE PAGES for ORCID "0000-0001-6267-3647"

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+ Show Author Affiliations

1. Georgia Institute of Technology, Atlanta, GA (United States)
2. Univ. of South Carolina, Columbia, SC (United States)

Publication Date:

Thu May 07 00:00:00 EDT 2020

Research Org.:

Pennsylvania State Univ., University Park, PA (United States)

Sponsoring Org.:

USDOE Advanced Research Projects Agency - Energy (ARPA-E); USDOE Office of Energy Efficiency and Renewable Energy (EERE)

OSTI Identifier:

1799502

Alternate Identifier(s):

OSTI ID: 1647390

Grant/Contract Number:  

EE0008433

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Materials Chemistry. A

Additional Journal Information:

Journal Volume: 8; Journal Issue: 34; Journal ID: ISSN 2050-7488

Publisher:

Royal Society of Chemistry

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Chemistry; Energy & Fuels; Materials Science