Two dimensional NMR and NMR relaxation studies of coal structure
This report covers the progress made on the title project during the past reporting period. Four major areas of inquiry are being pursued. Advanced solid state NMR methods are being developed to assay the distribution of the various important functional groups in coals that determine the reactivity of coals. Other methods are being developed which will also determine how these functional groups are linked together. A third area of investigation concerns how molecular mobility in coals impacts NMR relaxation times, which is important for interpretation of such data in terms of the mobile phase in coals model. Along the same lines the authors are also using these studies to establish protocols for obtaining the best quantitative response from coals in solid state C-13 NMR spectra. The effects of very high MAS rates (>10 kHz) on cross polarization dynamics are also being investigated for similar reasons. The authors have been reinvestigating the prospects of using zero field NMR types of techniques for two dimensional NMR structural analysis of complex organic solids such as coals. Currently MAS spin rates are not sufficiently high to permit zero field in high field NMR for protons in typical organic solids, however they are compatible with {sup 13}C-{sup 13}C dipolar couplings. In collaboration with Dr. Robert Tycko of AT T Bell Laboratories, inventor of the zero field in high field NMR method, the authors have performed the first zero field in high field {sup 13}C NMR experiments. These results are described. 9 refs., 2 figs.
- Research Organization:
- Yale Univ., New Haven, CT (USA). Dept. of Chemistry
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (USA)
- DOE Contract Number:
- FG22-87PC79910
- OSTI ID:
- 5993314
- Report Number(s):
- DOE/PC/79910-6; ON: DE91011280
- Country of Publication:
- United States
- Language:
- English
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Two dimensional NMR and NMR relaxation studies of coal structure
Two dimensional NMR and NMR relaxation studies of coal structure
Related Subjects
COAL
STRUCTURAL CHEMICAL ANALYSIS
NUCLEAR MAGNETIC RESONANCE
PERFORMANCE TESTING
CARBON 13
CROSS-LINKING
NMR SPECTRA
POLARIZATION
PROGRESS REPORT
RELAXATION
SPIN
ANGULAR MOMENTUM
CARBON ISOTOPES
CARBONACEOUS MATERIALS
CHEMICAL REACTIONS
DOCUMENT TYPES
ENERGY SOURCES
EVEN-ODD NUCLEI
FOSSIL FUELS
FUELS
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MATERIALS
NUCLEI
PARTICLE PROPERTIES
POLYMERIZATION
RESONANCE
SPECTRA
STABLE ISOTOPES
TESTING
010600* - Coal
Lignite
& Peat- Properties & Composition