Solid-State NMR Investigations of the Unusual Effects Resulting from the Nanoconfinement of Water within Amphiphilic Crosslinked Polymer Networks
✍ Scribed by Ryutaro Ohashi; Jeremy W. Bartels; Jinqi Xu; Karen L. Wooley; Jacob Schaefer
- Publisher
- John Wiley and Sons
- Year
- 2009
- Tongue
- English
- Weight
- 494 KB
- Volume
- 19
- Category
- Article
- ISSN
- 1616-301X
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Two types of solid‐state ^19^F NMR spectroscopy experiments are used to characterize phase‐separated hyperbranched fluoropolymer–poly(ethylene glycol) (HBFP–PEG) crosslinked networks. Mobile (soft) domains are detected in the HBFP phase by a rotor‐synchronized Hahn echo under magic‐angle spinning conditions, and rigid (hard) domains by a solid echo with no magic‐angle spinning. The mobility of chains is detected in the PEG phase by ^1^H → ^13^C cross‐polarization transfers with ^1^H spin‐lock filters with and without magic‐angle spinning. The interface between HBFP and PEG phases is detected by a third experiment, which utilized a ^19^F → ^1^H–(spin diffusion)–^1^H → ^13^C double transfer with ^13^C solid‐echo detection. The results of these experiments show that composition‐dependent PEG inclusions in the HBFP glass rigidify on hydration, consistent with an increase in macroscopic tensile strength.