| 초록 |
Nafion is the best-known membrane used as a proton conducting solid electrolyte in direct methanol fuel cells. A membrane electrode assembly (MEA), which comprises a polymer electrolyte membrane and catalyst coated electrodes for anode and cathode at both sides of the electrolyte membrane, is a key component of a fuel cell. In general, the three components of a MEA are hot pressed to increase the electric contact among the components. However, the molecular structure and the porosity of the PEM can be changed during the hot pressing process. In this work, we report the influence of hot pressing on the structure of Nafion membranes studied by proton NMR. The Nafion before and after hot pressing were studied by 1H NMR of water in the Nafions from room temperature to -95°C. The water contents in Nafion was observed to be reduced by hot pressing. However, hot pressing seems to reduce the number of pores but not to affect the pore size distribution in Nafion. |
