PPOs having piperidinium-based conducting head groups with extra molecular interaction sites as new anion exchange membranes. (29th April 2022)

• Record Type: Journal Article
• Authors: Mayadevi, T.S.; Min, Kyungwhan; Choi, Ook; Chae, Ji Eon; Kim, Hyoung-Juhn; Choi, Chan Hee; Kang, Hoseong; Park, Chi Hoon; Kim, Tae-Hyun
• Is Part Of: International journal of hydrogen energy. Volume 47:Number 36(2022)
• Page Start: 16222
• Page End: 16234
• Publication Date: 2022-04-29
• Subjects: Anion exchange membranes -- Conducting head groups -- Hydrogen bonding -- Enhanced alkaline stability -- Conducting highway; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2022.03.110
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Poly(2, 6-dimethyl-1, 4-phenylene oxide)s [PPOs] with 4-hydroxy-piperidinium and tropinium conducting head groups are developed, and corresponding membranes are investigated as new anion exchange membranes (AEMs). Their properties are compared with piperidinium-functionalized PPO membranes. The additional OH group in the piperidinium unit further enhances the chemo-physical stability of the corresponding membrane (OH-Pip-PPO) due to physical crosslinking through hydrogen bonding. The bulky structure of tropinium provides additional free volume in the corresponding membrane (Trop-PPO). Hydrogen bonding between the polymers and water causes well-developed morphology and high dimensional stability. These membranes also contain ion-conducting highways, facilitating efficient ion transport, in agreement with molecular dynamics simulations. The 4-hydroxy-piperidinium-functionalized PPO showed the highest dimensional and alkaline stability, with slightly lower conductivity and cell performance than piperidinium-functionalized-PPO (Pip-PPO) and Trop-PPO. Trop-PPO further increases free volume and water uptake, resulting in the highest normalized conductivity among the three PPO-based membranes and fuel cell performance similar to Pip-PPO. Graphical abstract: Image 1 Highlights: 4-Hydroxy-piperidinium and tropinium were used as new conducting head groups. OH groups on the conductor enhanced physicochemical stability of the AEMs. The bulky structure of tropinium further increased free volume and conductivity.