Charactrization and Electrochemical Investigation of a Novel High performance Nanocomposite Proton Exchange Membrane

Polyelectrolyte membranes based on Nafion and chitosan-functionalized montmorillonite (BMMT) were fabricated. X-ray diffraction analysis confirmed the exfoliated structure of clay. Methanol permeability results revealed that the presence of 10 wt% BMMT in synthesized nanohybrid membranes can reduce the permeability of to 5.72×10 -8 cm2 s−1 in comparison with 2.00×10−6 cm2 s−1 for that of Nafion® 117. However, proton conductivity of nanohybrids was decreasing with increasing BMMT loading, but obtained values were indicating the lower sacrificing of conductivity in comparison with membranes based on unmodified MMT. According to selectivity, membranes containing 2 wt% of BMMT showed optimum properties. It was suggested that improvement of transportation properties could be due to the electrostatic interaction between amino groups of chitosan and Nafion sulfone groups Considering the low methanol crossover, appropriate proton conductivity and suitable electrochemical properties, Nafion®/BMMT nanohybrid membranes, could be proposed as novel polyelectrolyte for direct methanol fuel cell application.

Keywords:

Biomodified montmorillonite , proton exchange nanocomposite membrane , direct methanol fuel cell