Carbon-13 and fluorine-19 nuclear magnetic resonance spectra of chemically derivatized, by phase transfer methylation and trifluoroacetylation, Athabasca oil sand asphaltene, reveal a broad site distribution of different types of hydroxyl-containing functional groups, viz., carboxylic acids, phenols, and alcohols. The low temperature air oxidation of asphaltene, at ca 130°C for 3 days, generates a few additional carboxyl and phenolic groups. These results are consistent with a mechanism in which diaryl methylene and ether moieties react with oxygen. Self-diffusion coefficients, from the pulsed field gradient spin-echo proton magnetic resonance technique, suggest that low temperature oxidation does not appreciably alter the average particle size and diffusion properties of asphaltene in deuterochloroform. © 1998 Elsevier Science Ltd. All rights reserved.
Desando, M. A., Lahajnar, G., Ripmeester, J. A., & Zupancic, I. (1999). The low temperature oxidation of Athabasca oil sand asphaltene observed from 13 C, 19 F, and pulsed field gradient spin-echo proton n.m.r. spectra. Fuel, 78(1), 31–45. https://doi.org/10.1016/S0016-2361(98)00125-2