| 초록 |
Direct methanol fuel cells (DMFCs) are suited for portable devices due to their high energy density and the ease of handing of a liquid fuel. Yet they have major drawbacks such as methanol crossover. In this study, in order to decrease the methanol crossover of the membranes for DMFCs, Nafion/Engelhard titanosilicate-4 (ETS-4) composite membranes with ETS-4 contents of 5, 10, 15, and 20 wt% were prepared by the solution casting method. Microporous ETS-4 will effectively block the methanol molecules by tortuous pathway effect because it plays a role as a size-selective adsorbent. The water uptake and selectivity of the composite membranes increased with an increase in the ETS-4 content, whereas their ion exchange capacity, proton conductivity, methanol permeability decreased due to the addition of ETS-4, which contains no sulfonic acid group. All things considered, 10 wt% loading was an optimized content of ETS-4 in the Nafion matrix to exhibit the best overall performance in DMFCs. |
