| 초록 |
Organic-inorganic hybrid membranes based on poly(ethylene glycol) (PEG) and sulfonated polyhedral oligomeric silsesquioxane (sPOSS), crosslinked by polyisocyanate, were prepared as candidate materials for methanol-based PEM fuel cells. We found that proton conductivity increased and methanol permeability decreased with increasing sPOSS content in the hybrid membrane. In particular, our hybrid membranes demonstrated proton conductivities as high as 1.1×10-1 S/cm at room temperature, which is comparable to that of Nafion™, while exhibiting one order-of-magnitude lower methanol permeability as compared to Nafion™. We postulate that the polar sulfonic acid groups of the incorporated sPOSS cages assemble to provide ion conduction paths while the hydrophobic portions of the same sPOSS cages combine to form a barrier to methanol permeation with improved thermal stability of the hybrid membrane. |
