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Nafion®/poly(vinyl alcohol) blends: effect of composition and annealing temperature on transport properties
Please use this identifier to cite or link to this item:
http://hdl.handle.net/1860/1138
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| Title: | Nafion®/poly(vinyl alcohol) blends: effect of composition and annealing temperature on transport properties |
| Authors: | DeLuca, Nicholas W.
Elabd, Yossef A. |
| Keywords: | Fuel Cell
Polymer Electrolyte Membranes
Polymer Blends
Barrier Membranes
Electrochemistry
Pervaporation |
| Issue Date: | 22-May-2006 |
| Publisher: | Elsevier Science B.V. |
| Citation: | Journal of Membrane Science, 282(1-2): pp. 217-224. http://www.elsevier.com/wps/find/journaldescription.cws_home/502692/description?navopenmenu=1 |
| Abstract: | In this study, the transport properties (proton conductivity and methanol permeability) of Nafion® 117, solution-cast Nafion®, poly(vinyl alcohol) (PVA), and Nafion®/PVA blend membranes were measured as a function of annealing temperature (60-250oC) and blend composition for application to the direct methanol fuel cell (DMFC). A Nafion®/PVA blend membrane at 5 wt% PVA (annealed at 230oC) resulted in similar proton conductivity, but 3 times lower methanol permeability compared to Nafion® 117. In addition, an unusual trend was observed in Nafion®/PVA (50 wt% PVA) blend membranes, where proton conductivity remained relatively constant, but methanol permeability decreased by approximately one order of magnitude with increasing annealing temperature. Infrared spectroscopy reveals a band shift in the hydroxyl peak to higher wavenumbers in Nafion®/PVA blends (25-90 wt% PVA) with increasing annealing temperature suggesting an increase in the interaction between the hydroxyl groups in PVA and the sulfonic acid groups in Nafion®. For Nafion® alone, proton and methanol transport rates increased and then decreased with increasing annealing temperature with a maximum at 210oC for both solution-cast and as-received (extruded) Nafion®. This trend coincides with two transition temperatures observed by other investigators using differential scanning calorimetry, suggesting that transport properties are affected by morphological changes in Nafion®. |
| URI: | http://hdl.handle.net/1860/1138 |
| Appears in Collections: | Faculty Research and Publications (CBE)
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