Thin, robust, and chemically stable photo-cross-linked anion exchange membranes based on a polychlorostyrene-b-polycyclooctene-b-polychlorostyrene ABA triblock polymer

Journal Article · Thu Mar 01 00:00:00 EST 2018 · Solid State Ionics

DOI:https://doi.org/10.1016/j.ssi.2017.12.031· OSTI ID:1477180

Liu, Ye; Pandey, Tara P.; Sarode, Himanshu N.; Kuo, Mei-Chen; Zhang, Wenxu; Gupta, Rohit; Galioto, Samuel; Ozioko, Amobi G.; Seifert, Soenke ; Liberatore, Matthew W.; Coughlin, E. Bryan ; Herring, Andrew M.

A polychloromethylstyrene-b-polypolycyclooctene-b-polychloromethylstyrene ABA triblock polymer was used as a backbone in a study to produce a chemically and mechanically robust anion exchange membrane (AEM). The material is easily scalable and the polypolycyclooctene segment (low T_m) makes the membrane flexible to handle. Comparison of the non-crosslinked triblock polymer functionalized with different cations namely; piperidinium, pyrrolidinium, tris(2,4,6-trimethoxyphenyl) phosphonium, and the benchmark trimethylammonium cation showed that the piperidinium functionalized membrane with an ionic exchange capacity of ca. 1.36 mmol.g^-1 had the highest OH^- conductivity ca. 95 mS·cm^-1 at 80 °C, 95% RH, and the highest Cl^- conductivity of ca. 31 mS·cm^-1 at 70 °C, 95% RH. The membrane with the piperidinium cation was the most chemically stable when immersed in 1 M KOH at 80 °C (with only 16% degradation after 14 days) compared to all the other cation functionalized membranes studied here. Photo-crosslinking with 1,10-decanedithiol (DT) eliminated the melting behavior of the polycyclooctene black and improved the mechanical stability of the films allowing < 20 μm large area transparent membranes to be produced. The DT cross-linking reduced the membrane swelling on all length scales as shown by small angle X-ray scattering, water uptake, and dimensional swelling data, and allowed the membrane to be fully intact even at fully hydrated states based on the tensile strength measurements.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES); US Army Research Office (ARO)
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1477180
• Journal Information: Solid State Ionics, Vol. 316, Issue C; ISSN 0167-2738
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

ABA triblock polymer
Anion exchange membrane
Cross-linked polymer
Hydroxide conductivity
Stable cations