The Study of Anthracene Aerosols by Solid-State NMR and ESR

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• 作者：Mark S. Solum ; John M. Veranth ; Yi-Jin Jiang ; Anita M. Orendt ; Adel F. Sarofim ; and Ronald J. Pugmire
• 刊名：Energy & Fuels
• 出版年：2003
• 出版时间：May 2003
• 年：2003
• 卷：17
• 期：3
• 页码：738 - 743
• 全文大小：115K
• 年卷期：v.17,no.3(May 2003)
• ISSN：1520-5029

文摘

The condensed solids from three aerosols resulting from heating anthracene in a drop-tubefurnace with a helium atmosphere at temperatures of 1250, 1300, and 1400 K were studied bycarbon-13 solid-state NMR and by ESR methods. The 1250 K sample consisted almost entirelyof unreacted anthracene. However, the proton T₁ value of 17.6 s allowed the principal values ofthe carbon-13 chemical shift tensors to be measured by the FIREMAT experiment. The 1400 Ksample appeared to be a two-component system; 9.5% (w/w) of the aerosol was extracted indichloromethane. The extract (tar) from the 1400 K aerosol was analyzed in terms of a standardset of structural and lattice parameters. The average aromatic cluster size was found to be about15 carbons with approximately 1.4 attachments per cluster. The NMR spectrum of the extractionresidue (soot) of the 1400 K aerosol consisted of a broad featureless signal. The sample was veryconductive, yielding a graphite-like factor of 0.47. The unpaired electron spin concentration was1.2 × 10¹⁷ spins/g for the extract (tar) and 1.1 × 10²⁰ spins/g for the residue (soot).