Modification of nafion membrane by Iranian scientists

Iranian researchers from Amir Kabir University of Technology succeeded in the modification of a commercial type of membrane in fuel cells by using nanotubes. The new nanocomposite membrane was also studied in this research to be used as electrolyte in methanol based fuel cells. In this research, nanotubes modified with histidine were used to modify the disadvantages of Nafion® membrane in fuel cells, including high passing of fuel, low conductivity of proton, and low operational temperature. The characteristics of the new nanocomposite membrane was investigated as well in order to be used as electrolyte in methanol based fuel cells. The innovation in this research is the use of histidine to functionalize and modify the multi-wall nanotube structure. Histidine is an aminoacid that has carboxylic acid, amine and azole groups.  The use of nanotube modified with histidine creates appropriate interaction between aminic acid azole group and proton ions, and improves the performance of fuel cells, specially at high temperatures. In addition, the biocompatible nature of histidine provides high potential for this membrane in biological media. In commercial membranes, when water evaporates at high temperature, proton transfer mechanism fails and the performance of the fuel cell decreases. Therefore, the use of Grotthuss-type mechanism with azole functional groups in the membrane designed in this research increases the efficiency of the fuel cell at high temperature. Among other advantages of the designed membrane, mention can be made of low passing of methanol and high productive ability of the membrane in comparison with other commercial membranes. Results of the research have been published on 10 May 2013 in International Journal of Hydrogen Energy, vol. 38, issue 14, pp. 5894-5902.