Nano composite membranes of branched sulfonated poly(ether ketone sulfone) and SiO2 for fuel cell application

Branched sulfonated poly(ether ketone sulfone) copolymer was prepared from 1,1,1-tris(4-hydroxyphenyl) ethane, 4,4-difluorophenylsulfone, 3,3'-disodiumsulfonylbenzophenone (40 mol% of bisphenol A) and bisphenol A by polycondensation with the elimination of water in toluene and NMP at 160 rectangle in the presence of anhydrous potassium carbonate. Composite membranes were successfully cast from the control of organic polymer with SiO2 4-10 wt% of polymer in DMSO. The films were converted from the salt to acid forms with dilute hydrochloric acid. Organic-inorganic composite membranes for operation in polymer electrolyte membrane fuel cells (PEMFCs) were characterized and cell-tested. The physico-chemical properties of all membranes were investigated their thermal properties, water uptake, DSC and thermogravimetric analyzer (TGA). Branched copolymer and nano composite membranes exhibit proton conductivities from 1.7x 10(-3) to 8.3x 10(-3) S/cm(2), water uptake from 22 to 26%, IEC from 1.28 to 1.46 meq/g and methanol diffusion coefficients from 1.2x 10(-7) to 1.7x 10(-7) cm(2)/S.