Polyelectrolyte nanocomposite membranes based on chitosan and surface modified multi-walled carbon nanotubes for use in fuel cell applications

Abstract

Nanocomposite polyelectrolyte membranes (PEMs), based on chitosan, and imidazole surface modified multi-walled carbon nanotubes (MWCNT-Im), were fabricated as new alternative membranes to Nafion for direct methanol fuel cell (DMFC) applications. The characterization results revealed that the imidazole groups, as proton conducting sites, can provide the better dispersion of the nanofillers, enhance the proton conductivity, reduce the methanol permeability, and finally, provides the higher selectivity parameter, compared to the commercial Nafion® 117 membranes. In fact, due to the hydrogen bonding interactions between the imidazole groups in MWCNT-Im and chitosan chains, new proton conducting pathways are formed resulting in the higher selectivity parameter.