The clustered water and interfacial water in Nafion 117 membrane have been quantified by NMR deuterium and proton experiments. The oscillation of intensity profile in 2H CPMG sequence with large duration time is induced by the residual quadrupolar interaction in clustered water. While the intensity profile of 2H CPMG sequence at short duration time followed the rule of exponential decay which is the consequence of the profile-overlapping between clustered water with residual quadrupolar interaction and interfacial water with susceptibility effect.
The populations of clustered water and interfacial water in fully hydrated membrane are estimated by quadrupolar echo sequence. The population of former and latter is 70% and 30%,respectively. At an elevated temperature, water in cluster region can transport to the interfacial region and result in change of intensity for proton spectrum. The activation energy of translational diffusion of interfacial water is lower than that of clustered water due to the strong binding energy between sulfonate group and water molecule.
The rf-heating effect on the proton spectrum of clustered water also has been explored by 1H CPMG and rotating-frame-relaxation-dispersion experiments. The dielectric response to a time-dependent external electric field provides a source of heat which causes a drift in chemical shift and interfere with transverse relaxation .
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0910112-165126 |
| Date | 10 September 2012 |
| Creators | Wu, Zhen |
| Contributors | Chao-Ming Chiang, Shangwu Ding, Peter Po-Jen Chu, Michael Y. Chiang, Shiao Wei Kuo, Shuchen Hsieh |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0910112-165126 |
| Rights | user_define, Copyright information available at source archive |
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