Generation, characterization and applications of fullerenes
A contact-arc sputtering configuration has been adopted and optimized in order to generate fullerene-containing soot. Several stages of design improvements have made the equipment more effective in terms of yield and production rate. Upon modification of Wudl's Soxhlet separation procedure, the authors have been able to significantly speed up C[sub 60] separation and higher fullerene enrichment. At least ten more separable HPLC peaks after C[sub 84] have been observed for the first time. Preliminary laser desorption time of flight mass spectra suggest that the enriched higher fullerene sample possibly contains, C[sub 86], C[sub 88], C[sub 90], C[sub 92], C[sub 94], and C[sub 96] in addition to the previously isolated smaller fullerenes C[sub 60], C[sub 70], C[sub 76], C[sub 78](D[sub 2]), C[sub 78](C[sub 2v]) and C[sub 84]. Among these, C[sub 86], C[sub 88], C[sub 92] show up for the first time in separable amounts and the controversial species-C[sub 94] appears present too. HPLC has been successfully used for high fullerene separation, pure C[sub 76], C[sub 84] samples so far having been obtained. Fullerene decomposition (especially of higher fullerenes) in the column has been clearly identified. The defined HPLC peaks indicate that the oxidation process may follow certain [open quotes]well defined[close quotes] routes. A yellow epoxide band containing various oxides of C[sub 60] has been extracted and characterized using mass spectrometry. Characterizations of pure C[sub 60] and C[sub 70] include HPLC, mass spectrometry, vibrational IR and Raman spectroscopy, STM, TEM etc. Raman measurements completed the full assignment of C[sub 60] fundamental modes and supplied more structural information on C[sub 70]. STM imaging supplied clear pictures of both C[sub 60] and C[sub 70] molecular topologies. Especially for C[sub 70], both the long and the short axes of the molecule have been clearly resolved.
- Research Organization:
- Northwestern Univ., Chicago, IL (United States)
- OSTI ID:
- 7069680
- Resource Relation:
- Other Information: Thesis (Ph.D.)
- Country of Publication:
- United States
- Language:
- English
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