Conductive polysaccharides-based proton-exchange membranes for fuel cell applications: the case of bacterial cellulose and fucoidan

• Autor(a) principal: Vilela, Carla
• Data de Publicação: 2020
• Outros Autores: Silva, Ana C. Q., Domingues, Eddy M., Gonçalves, Gil, Martins, Manuel A., Figueiredo, Filipe M. L., Santos, Sónia A. O., Freire, Carmen S. R.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/36957
• topic: Bacterial cellulose; Fucoidan; Proton-exchange membranes; Protonic conductivity; Fully bio-based separators

Conductive natural-based separators for application in polymer electrolyte fuel cells (PEFCs) were fabricated by combining a bacterial polysaccharide, i.e. bacterial cellulose (BC), and an algae sulphated polysaccharide, i.e. fucoidan (Fuc). The diffusion of fucoidan aqueous solution containing a natural-based cross-linker, viz. tannic acid, into the wet BC nanofibrous three-dimensional network, followed by thermal cross-linking, originated fully bio-based proton exchange membranes (PEMs). The PEMs present thermal-oxidative stability in the range of 180-200 °C and good dynamic mechanical performance (storage modulus ≥ 460 MPa). Additionally, the BC/Fuc membranes exhibit protonic conductivity that increases with increasing relative humidity (RH), which is a typical feature for numerous water-mediated proton conductors. The traditional Arrhenius-type plots demonstrate a linear behaviour with a maximum protonic conductivity of 1.6 mS cm-1 at 94 °C and 98 % RH. The results showed that these fully bio-based conductive membranes have potential as eco-friendly alternatives to other PEMs for application in PEFCs.