Enhanced performance of the sulfonated polyimide proton exchange membranes by graphene oxide: Size effect of graphene oxide

A series of composite proton exchange membranes for DMFCs were prepared by introducing different sizes of GOs into sulfonated polyimide (SPI). The incorporation of GOs not only improved the mechanical properties and thermal stability of the SPI-GOs composite membranes, but also obviously increased their proton conductivity and reduced the methanol permeability through the membrane.282