Sulfonated multiwalled carbon nanotube/sulfonated poly(ether sulfone) composite membrane with low methanol permeability for direct methanol fuel cells

Abstract

Abstract An organic/inorganic composite membrane was prepared based on sulfonated poly(ether sulfone) (s‐PES) embedded with sulfonated multiwalled carbon nanotubes (s‐MWNTs). The ion exchange capacity (IEC), proton conductivity, and water uptake of the SPES membranes increased with increasing s‐MWNTs content. The increased water uptake was attributed to hydrogen bond formation between the carbonyl group of the s‐MWNTs and a water molecule. The composite membranes exhibited proton conductivities ranging from 3.9281 × 10 −4 to 7.0788 × 10 −3 S/cm at 80°C, as well as low methanol permeability ranging from 4.4405 × 10 −10 to 9.1008 × 10 −10 cm 2 s −1 at 25°C. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012