초록 |
Proton exchange membranes (PEMs) consisting of sulfonated poly(arylene ether ketone) (SPAEK) with silica nanoparticles are developed for fuel cell applications under low relative humidity (RH). An asymmetric distribution of surface modified silica nanoparticles with hydrophilic and hydrophobic is applied for enhancing the water back diffusion from cathode to anode through the membrane. Moreover, cross-linked structure between SPAEK polymers and silica nanoparticles promoted proton conductivity that attributed to the synergistic effect of well-connected hydrophilic proton channels and improved the dispersion of silica nanoparticles in the polymer matrix. The nanostructure of the membranes was investigated by field-emission transmission electron microscopy (FE-TEM), atomic force microscopy (AFM) and small angle X-ray scattering (SAXS). Furthermore, the composite membrane exhibited enhanced mechanical stability due to the effectively cross-linked networks between SPAEK and silica. |