Performance of SPEEK based polymer-nanoclay inorganic membrane for DMFC

Sulfonated poly (ether ether ketone) (SPEEK) membrane with degree of sulfonation (DS) of 63% was modified by adding various amounts of Cloisite15A (R) clay. The effect of clay loading on the physical properties of SPEEK nanocomposite membranes was investigated. SPEEK mixed with 2.5 wt.% of Cloisite15A (R) (SP63/2.5Cl) has been identified as the best composite formulation in this study. Subsequently, various amounts of 2,4,6-triaminopyrimidine (TAP) were further incorporated into SP63/2.5Cl formulation. The effect of TAP incorporation on the physical and performance properties of the membranes was studied. Nanometer scale distribution of Cloisite15A (R) in the SPEEK polymer matrix has been achieved by the assistance of TAP, as observed by the field emission scanning electron microscopy (FESEM). A complete exfoliated nanocomposite structure of SP63/2.5Cl/5.0TAP was confirmed by X-ray diffraction (XRD). The increase of Cloisite15A (R) content in the SPEEK membrane has dramatically improved the swelling behavior and barrier properties towards methanol. The SP63/2.5Cl/5.0TAP polymer-clay nanocomposite membrane served as a promising alternative proton exchange membrane (PEM) for DMFC applications with superior DMFC performance compared to commercial Nafion (R) 112. (C) 2011 Elsevier B.V. All rights reserved.