Fuel cells are an attractive alternative to many energy conversion or storage devices. Among the various types of fuel cells, direct methanol fuel cells (DMFCs) are suitable for portable devices or transportation applications. The proton exchange membrane (PEM) material is a key component of the DMFCs. It is work as media for conducting protons from the anode to the cathode. They also provide a barrier against methanol cross-over between electrodes. Hydrophilic membranes based on chitosan are widely used in membrane applications due to its high hydrophilicity, good chemical/thermal resistance and high mechanical strength properties. So our aim in this study was to develop a novel high performance and also low cost proton conducting membranes based on chitosan. To reduce methanol crossover of membrane while maintaining essential proton conductivity, we have investigated the preparation of polymer-zeolites nanocomposite membranes. Nanocomposites were prepared by incorporating of nanoscale ZSM-5 zeolite (SiO₂/Al₂O₃=25) into chitosan biopolymer. Membranes were fabricated by solution-casting technique. Synthesized membranes were cross linked for improved dimensional stability in aqueous environments. Morphology of composites was studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Sorption studies indicated that the degree of swelling for ZSM-5 filled membranes increased with zeolite content. The transport properties were characterized by measuring the methanol diffusion coefficient and proton conductivity as functions of nanoparticle loading weights. Fabricated membranes from cross-linked chitosan with ZSM-5 showed higher membrane selectivity (ratio of proton conductivity to methanol permeability) compared to Nafion117 as a commercial PEM. According to results, the nanocomposites based on chitosan biopolymer and zeolitic molecular sieves are excellent candidate for fuel cells applications.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/16046 must be provided.

1. Effect of silicate nanosheets on nanochannel morphology of polymeric ionomers