Calculation of the heat capacity of coals according to their elemental composition and the degree of aromaticity of the organic matter : Gagarin, S. G. and Gyul'maliev, A. M. Khimiya Tverdogo Topliva (Moscow, Russian Federation), 2002, (3), 3–11. (In Russian)
- Publisher
- Elsevier Science
- Year
- 2003
- Weight
- 272 KB
- Volume
- 44
- Category
- Article
- ISSN
- 0140-6701
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✦ Synopsis
A new method for estimating the average fraction of graphitic structure (the graphite-like factor) found in carbonized materials such as anthracitic coals and soots has been developed. This method employs a Q meter, a device that can be used to measure the resistance of a coil at high frequency.
The resistance, and therefore the Q response, depends on the conductive behaviour of the delocalized electrons in the sample placed inside a RF coil. On the basis of the Q measurement, one can estimate the percentage of the sample that contains graphitelike regions in which delocalized conduction electrons exist. A series of measurements was made on a set of graphite and silica gel mixtures in order to calibrate the measured Q values. This method was then applied to a series of anthracitic coal samples and a number of soot samples. The Q values obtained were related to the graphitic content of the soot or coal. These results are compared with carbon-13 NMR data and ESR unpaired electron spin concentration measurements.