Tailoring highly stable anion exchange membranes with graft molecular structure ordering using reversible addition-fragmentation chain transfer polymerization for alkaline fuel cells

Autor(es)

Santos, Bianca Pedroso S. ; Barbosa, Andrey S. ; Kodama, Yasko ; de Queiroz, Thiago B. ; Santiago, Elisabete I.

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF MEMBRANE SCIENCE; v. 687, p. 12-pg., 2023-09-16.

Resumo

The radiation-induced grafting is used to prepare a variety of anion-exchange membranes (AEM) based on poly (ethylene-co-tetrafluoroethylene) (ETFE) utilizing a reversible addition-fragmentation chain transfer (RAFT) agent. The copolymerization process is controlled by the RAFT agent, resulting in AEMs with a restricted molecular weight dispersion. As a result, RAFT-AEMs exhibit decreased water uptake and reduced swelling. A significant improvement in thermal and mechanical characteristics is evidenced, while the conductivity remains practically unaltered. Anion-exchange membrane fuel cell (AEMFC) tests revealed that conventional RIG-AEMs and RAFT-AEMs with low RAFT content (5 wt%) have comparable beginning-of-life performances (similar to 0.95 W cm(-2)). However, for higher RAFT contents, the performance trends to decrease indicating an imbalance in water management. Furthermore, short-term stability tests suggest that RAFT-AEMs are able to operate highly stable, with a conductivity rate loss of 0.05% h(-1), which represents an improvement of 160% in comparison to conventional RIG-AEM. AFM analysis demonstrated that structural ordering molecular and morphology tailor the fundamental properties of ETFE-based AEMs, combining enhanced performance and stability for alkaline fuel cell applications. (AU)

• Processo FAPESP: 20/13466-1 - Design, síntese e caracterização de sistemas moleculares para colheita de luz e separação de cargas
• Beneficiário: Thiago Branquinho de Queiroz
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores
• Processo FAPESP: 17/11937-4 - Rota sustentável para a conversão de metano com tecnologias eletroquímicas avançadas
• Beneficiário: Fabio Coral Fonseca
• Modalidade de apoio: Auxílio à Pesquisa - Programa Centros de Pesquisa em Engenharia