초록 |
Perfluorosulfonic acid membranes with the trade name Nafion are the most commonly used electrolyte in PEM fuel cells because of their high proton conductivity and chemical stability. Although the Nafion has many benefits, it is not satisfactory in many aspects especially due to high methanol crossover when fueled with methanol. In order to overcome this drawback, we prepared crosslinked nafion membranes, The in-situ crosslinking of sulfonic acid was performed by addition of 1,1'-carbonyldiimidazole (CDI) and diamines as crosslinking agents. The diamines are two types. One contains sulfonic acid groups, aromatic rings, ether and sulfone linkages, the other contains same chemical linkages except sulfonic acid groups. Both of amines we synthesized are confirmed by 1H-NMR. The formation of sulfonamide linkages was confirmed by ATR-FTIR and UV-vis spectroscopy. The performance of the membranes was measured in terms of IEC (ion exchange capacity), water uptake, proton conductivity, and vanadium permeability. |