Sulfonated polyether ether ketone composite membrane using tungstosilicic acid supported on silica-aluminium oxide for direct methanol fuel cell (DMFC)

New composite membranes were prepared using sulfonated polyether ether ketone (SPEEK) polymer and inorganic proton conducting fillers developed from tungstosilicic acids (SiWA) loaded on silica-aluminium oxide (SiO2-Al2O3) Composite. SiWA was fixed on stable structure (composite oxide) so that it became insoluble in water. The SPEEK polymers were characterized using H NMR and FTIR. XRD analysis was performed on the inorganic proton conducing fillers to reveal the existence of the interaction between SiWA and composite oxide. The membrane structural properties and surface morphologies were characterized with SEM and their performance were examined in terms of proton conductivity, water uptake and methanol permeability. It was found that the presence of inorganic proton conducting fillers led to both high water uptake and proton conductivity (maximum value 6.1 x 10(-2) Scm(-1)). Low methanol permeability values were recorded for the membranes which appeared as a very promising material to be used in DMFC. (c) 2008 Elsevier B.V. All rights reserved.