Water properties in the super-salt-resistive gel probed by NMR and DSC
The so-called "super-salt-resistive gel", or poly(4-vinylphenol) (P4VPh) hydrogel, of different water contents ( H = 97-51%) was prepared by cross-linking with different amounts of ethylene glycol diglycidyl ether. 1H NMR spectroscopy was used to investigate the dynamic properties of water...
| Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1999. - 24(2008), 13 vom: 01. Juni, Seite 6981-7 |
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| Weitere Verfasser: | , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2008
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| Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
| Schlagworte: | Journal Article Cross-Linking Reagents Gels Polyvinyls Salts poly(4-vinylphenol) Water 059QF0KO0R Polyvinyl Alcohol 9002-89-5 |
| Zusammenfassung: | The so-called "super-salt-resistive gel", or poly(4-vinylphenol) (P4VPh) hydrogel, of different water contents ( H = 97-51%) was prepared by cross-linking with different amounts of ethylene glycol diglycidyl ether. 1H NMR spectroscopy was used to investigate the dynamic properties of water in the gel samples in terms of the spin-spin relaxation. The T2 values in those hydrogels were analyzed by assuming a two-component system, namely, T 2(long) and T2(short), and their fractions were obtained. In the higher water content region (75% < or = H < or = 97%), T2(long) for P4VPh gel was almost constant or even slightly increased with decreasing temperature. On the other hand, T2(long) for poly(vinyl alcohol) (PVA) gel (80% < or = H < or = 96%) significantly decreased with decreasing temperature, showing a natural behavior for water mobility in common hydrogels. Water in P4VPh gels of lower water contents ( H = 70% and 51%) also showed intriguing behaviors: the T2 values are much larger than those of gels with higher water contents and decreased with decreasing temperature only in the lower temperature range (<10 degrees C). The fraction of T2(long) values of P4VPh gel showed another contrast to those of PVA gel; the latter decreased with decreasing water content (normal behavior), while in the former gel the highest fraction (ca. 60% at 20 degrees C) was observed for a sample with the lowest water content ( H = 51%). On the other hand, the results of DSC measurements for P4VPh gel were less specific than those of T2 and comparable to those of common hydrogels such as PVA; with decreasing water content, the total amounts of free water and freezable bound water per polymer mass (g/g) decreased, while the amount of nonfreezing water per polymer also decreased |
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| Beschreibung: | Date Completed 15.08.2008 Date Revised 21.11.2013 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1520-5827 |
| DOI: | 10.1021/la800397f |