Advancement of the Process for Extraction, Chromatography and Characterization of Fullerenes

Abstract

In the first phase of this work, the basic C₆₀ and C₇₀ as well as the higher fullerenes, mainly C₇₆ and C₈₄, were Soxhlet extracted with p‐xylene and n‐heptane from the samples of carbon soot, produced in electrical arc, yielding 5.9% and 0.7% of the extract, respectively. The remaining, p‐xylene insoluble soot was then extracted with pyridine, by original advanced method, increasing the entire extract yield for an additional 5.9% to 11.8%. The procedures for increases of the basic and higher fullerenes yields, as well as for additional, selective extraction of the higher fullerenes were found. Chromatographic separation of the basic and the higher C₇₆ and C₈₄ fullerenes from p‐xylene extract was performed by continual elution, in one phase of the process, under atmospheric pressure, with original, defined, gradient of solvents from 5% toluene in hexane to pure 100% toluene, on active Al₂O₃ column, by a new, improved method. Identifications of the basic and the higher fullerenes in chromatographically purified fractions, as well as in the obtained extracts, were performed using determined techniques of IR and UV/VIS spectroscopy that have not been presented previously for the higher fullerenes.

Keywords:

• Carbon soot
• Basic and higher fullerenes
• Soxhlet extractions
• Chromatography
• IR
• UV/VIS

ACKNOWLEDGMENTS

We are grateful to Ministry of Science, Serbia, for financial support of the project TR6349 and to MER Corporation, Tucson, USA for carbon soot material.