Sulfonated poly (ether ether ketone)/polyvinylidene fluoride polymer blends for direct methanol fuel cells

There have been many novel materials proposed to reduce methanol crossover for direct methanol fuel cells (DMFCs). In this study, polymer blends of sulfonated poly (ether ether ketone) (SPEEK) with polyvinylidene fluoride (PVDF) were prepared. The effects of methanol concentration and membrane composition on the mechanical stability and proton conductivity of the membranes were investigated. The liquid uptake of the 9/1 SPEEK/PVDF blend membrane is about 20%,, and the value of proton conductivity of this membrane is 1.75 x 10(-3) S cm(-1), which is about 9% that of Nafion(R) 115. The methanol permeability of 9/1 SPEEK/PVDF blend membrane is about 1/20 that of Nafion(R) 115 on the same testing condition. Based on the preliminary results, it can be concluded that the polymer blends of SPEEK/PVDF can be considered as a candidate membrane materials for DMFCs applications. (C) 2005 Elsevier B.V. All rights reserved.