Selective measurement of heteronuclear 1H-13C dipolar couplings in motionally heterogeneous semicrystalline polymer systems
Language English Country United States Media print
Document type Journal Article, Research Support, Non-U.S. Gov't
PubMed
16833857
DOI
10.1021/jp0503821
Knihovny.cz E-resources
- MeSH
- Alanine chemistry MeSH
- Bentonite chemistry MeSH
- Carbon Isotopes chemistry MeSH
- Caprolactam analogs & derivatives chemistry MeSH
- Magnetic Resonance Spectroscopy MeSH
- Nanocomposites MeSH
- Polyethylenes chemistry MeSH
- Polymers chemistry MeSH
- Hydrogen chemistry MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Alanine MeSH
- Bentonite MeSH
- Carbon Isotopes MeSH
- Caprolactam MeSH
- nylon 6 MeSH Browser
- Polyethylenes MeSH
- Polymers MeSH
- Hydrogen MeSH
A pulse sequence for the selective recoupling of heteronuclear dipolar interactions in mobile amorphous phase of powdered semicrystalline polymers is described. 1H-13C dipolar interactions are selectively measured by PISEMA-type sequence. Selection of 13C magnetization originating from amorphous phase is achieved by a train of saturation pulses followed by a short delay and a direct excitation pulse on 13C spins. The development of undesired net 13C magnetization during the recoupling sequence is prevented by the efficient "reverse" 13C --> 1H cross-polarization. The efficacy of the 2D method to measure 1H-13C dipolar couplings selectively for mobile components is demonstrated on powdered crystalline L-alanine, semicrystalline polyethylene, and nanocomposite polyamide-6/montmorillonite.
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