Solid state NMR methods for coal science. Progress report, July 1, 1985-September 30, 1985
This report covers the progress made on the title project during the last quarter. During the last three months we have concentrated on further developing a new 2-D NMR method that should be useful for coals. As outlined in a previous report this new technique separates the contribution of methines, methylenes and methyl or quaternary carbons to the carbon-13 CPMAS spectra of coals. In contrast to the heteronuclear shift correlation method, which observes only protonated carbons, this method observes all carbon centers seen in a standard CPMAS spectrum. The method has been successfully applied to polystyrene in which a methylene and methine resonance overlap. In this system we have a worst case as the interpretation is somewhat complicated by molecular motion in the solid. The results are still close to quantitative even with this complication. We have also investigated a new series of pulse sequences that we call Echo train NMR that were discovered in our earlier studies on decoupling methods. These sequences will be principally useful in enhancing the sensitivity of powder NMR spectra. In many cases the peak signal to noise of powder spectra can be enhanced by factors of up to 100. 6 figs.
- Research Organization:
- Yale Univ., New Haven, CT (USA). Dept. of Chemistry
- DOE Contract Number:
- FG22-83PC60791
- OSTI ID:
- 6174946
- Report Number(s):
- DOE/PC/60791-8; ON: DE86008353
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
010600* -- Coal
Lignite
& Peat-- Properties & Composition
CARBON 13
CARBON ISOTOPES
CARBONACEOUS MATERIALS
CHEMICAL SHIFT
COAL
DATA
DEUTERIUM
ENERGY SOURCES
EVEN-ODD NUCLEI
EXPERIMENTAL DATA
FOSSIL FUELS
FUELS
HYDROGEN ISOTOPES
INFORMATION
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MATERIALS
MEASURING INSTRUMENTS
NMR SPECTRA
NMR SPECTROMETERS
NUCLEAR MAGNETIC RESONANCE
NUCLEI
NUMERICAL DATA
ODD-ODD NUCLEI
OPTIMIZATION
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PETROCHEMICALS
PETROLEUM PRODUCTS
PLASTICS
POLYMERS
POLYOLEFINS
POLYSTYRENE
POLYVINYLS
POWDERS
RESEARCH PROGRAMS
RESONANCE
SPECTRA
SPECTROMETERS
STABLE ISOTOPES
STRUCTURAL CHEMICAL ANALYSIS
SYNTHETIC MATERIALS