Jornal de Ciência e Tecnologia de Membranas

Abstrato

Comparative Study between Sulfonation and Phosphoration forCommercial PTFE grafted with Styrene for Fuel Cell Application

E.E Abdel-Hady, M.O. Abdel-Hamed, M.M. El-Toony and M.R. El-Sharkawy

Simultaneous gamma irradiation was used for grafting of styrene onto commercial PTFE films. Different parameters affecting the grafting such as solvent, irradiation dose and monomer concentration were investigated. Sulfonation was performed using chlorosulfonic acid while phosphoric acid treatment was done in advance. Studying the role of phosphoric acid treatment for facilitating sulfonation of styrene grafting the PTFE membranes was carried out. FTIR spectroscopy and X-ray diffraction study confirmed the grafting and furthermore phosphoration and / or sulfonation. Scanning electron(SEM) was performed to characterize the morphological structure. Mechanical properties were discussed by measuring the hardness while chemical stability measurement assure their duration availability. Thermal characterization was investigated to proved the membrane applicability through wide range of temperature. Water uptake and ion exchange capacity were determined prior to measure the electrical conductivity and capacitance at different frequencies to assure the applicability of the grafted membranes in the fuel cell. Raising the temperature to 80°C increasing the Ec value to 1.08 x 10-1 S/cm which is well comparable to that of Nafoin.