Chitosan/magnetic chitin nanowhisker polyelectrolyte membrane for direct methanol fuel cell applications: preparation, characterization, and performance analysis

A hybrid chitosan-based nanocomposite was fabricated by chitin nanowhiskers coupled with silanized Fe3O4 nanoparticles as a polyelectrolyte membrane for direct methanol fuel cells (DMFCs). The morphological evaluations articulated that the magnetite nanoparticles were uniformly attached to the chitin nanowhiskers. After characterization of the synthesized nanowhiskers, they were incorporated into the chitosan, as a polycationic electrolyte, to investigate the performance of nanocomposite for DMFC applications. An external magnetic field was applied to the magnetic chitin nanowhiskers to induce alignment, and the effects of aligned nanowhiskers, as well as random ones, were also studied. The magnetic chitin nanowhiskers positively influenced the water uptake and proton conductivity due to the formation of hydrogen bonds between the surface functional groups of nanowhiskers and free water molecules. On the other hand, methanol permeation of the chitosan nanocomposites was reduced regarding the tortuous pathways and narrower transportation channels by the presence of nanowhiskers. [GRAPHICS] .