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| Type |
Symposium |
| Area |
Polymeric Materials for Energy Applications |
| Room No. |
Room 301 |
| Time |
FRI 15:50-: |
| Code |
POLY3-5 |
| Subject |
NMR Investigation of Water/Proton Dynamics in Polymer Electrolyte Membranes |
| Authors |
Oc Hee Han
Western Seoul Center, Korea Basic Science Institute, Korea |
| Abstract |
Probing the behavior of chemical species confined in the nano-meter scale spaces such as hydrophilic channels in polymer electrolyte membranes (PEM) can enhance our understanding on the mechanism of ion transport in electrochemical systems. Our Overhauser dynamic nuclear polarization (ODNP) nuclear magnetic resonance (NMR) data indicate that water in the middle of the hydrophilic channel moves slower than those close to the channel inner walls in PEM. The 1H magic angle spinning (MAS) NMR spectra of the Nafion membranes thermally degraded by replacing SO3H groups with H show that the water exposed to more hydrophobic environment moves faster. This result agreed with the ODNP results described above. In addition, the MAS NMR data manifest that the chemical shift of channel water is an indicator not only of the number of water per SO3H group but also of the degree of hydrophobicity where water is placed. Our finding implies that water/proton transport can be improved by chemical modification of the hydrophilic channel surfaces. |
| E-mail |
ohhan@kbsi.re.kr |
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121st General Meeting of the KCS