The characterization of fluorinated graphite
- Oak Ridge National Lab., TN (United States)
The characterization of solid fossil fuels by chemical and spectroscopic methods requires extensive modelling in less complex systems for chemical proof of principle and technique development. In previous work coal was fluorinated with dilute, elemental fluorine under conditions that were expected to lead to materials that contain only fluoromethine moieties, The solid state, cross polarization/magic angle spinning (CP/MAS) {sup 13}C NMR spectra of the fluorinated coal are complex, indicating more chemical modification than originally anticipated. Our goal in the coal derivatization was to sequentially increase the severity of the fluorination and observe by {sup 19}F and {sup 13}C NMR the type and concentration of fluorine functional groups created in the coal milieu. This requires the ability to discriminate between C, CF, CF{sub 2}, and CF, moieties in the coal matrix. The task can be accomplished by implementing the spectral editing technique of Wu and Zilm which distinguishes different kinds of carbon resonances, especially CH and CH, resonances. These experiments utilize cross polarization (CP) and polarization inversion (PI) to effect the discrimination. Our version of this experiment is a triple resonance experiment that incorporates {sup 19}F-{sup 13}C CP, PI, and simultaneous {sup 1}H and {sup 19}F dipolar decoupling.
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 420576
- Report Number(s):
- CONF-950801--
- Journal Information:
- Preprints of Papers, American Chemical Society, Division of Fuel Chemistry, Journal Name: Preprints of Papers, American Chemical Society, Division of Fuel Chemistry Journal Issue: 3 Vol. 40; ISSN 0569-3772; ISSN ACFPAI
- Country of Publication:
- United States
- Language:
- English
Similar Records
Introduction of fluorine into coals using N-fluorobenzenesulfonimide
1 H- 19 F REDOR-filtered NMR spin diffusion measurements of domain size in heterogeneous polymers