Optimization of anionic conductivity through the coexistence of ionomer cluster and backbone‐backbone morphologies in anion exchange membranes
Abstract
Random copolymers of poly(4‐vinylpyridine) and polyisoprene were synthesized, and subsequently quaternized with 1‐alkylbromides. The number of carbons on the pendant side‐chain of the resultant comb‐shaped polymer, n, ranged from 2–8. The comb‐shaped polymers were crosslinked employing thiol‐ene chemistry to give mechanically robust ion conducting membranes. Analysis by wide and medium‐angle X‐ray scattering show three morphology regimes that are dependent on the number of carbons on the pendant side‐chains. When n = 2, ionomer cluster morphology was dominant, when n = 8 backbone‐backbone morphology was dominant, and when n = 3–6, the membrane showed a coexistence of both ionomer cluster and backbone‐backbone morphologies. Evaluation of the water uptake of the membranes showed a maximum water uptake per cation of 9.5 when n = 5 at 95% relative humidity (RH) and 60°C. Conductivity of the samples characterized by electrochemical impedance spectroscopy showed bromide conductivity as high as 110 mS/cm when n = 3 at 95% RH and 90°C.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 07, 2020
- Source ID
- 10.1002/pol.20200629
Entities
People
- Andrew M Herring
- Chinomso Nwosu
- E. Bryan Coughlin
- Soenke Seifert
- Tara P. Pandey
Organizations
- Argonne National Laboratory
- Army Research Office
- Colorado School of Mines
- United States Department of Energy