THE ROLE OF POLYCYCLIC AROMATIC HYDROCARBONS IN THE STUDY OF FULLERENE FORMATION

Persistent Link:
http://hdl.handle.net/10150/187566
Title:
THE ROLE OF POLYCYCLIC AROMATIC HYDROCARBONS IN THE STUDY OF FULLERENE FORMATION
Author:
Zumwalt, Michael Crane
Issue Date:
1995
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Two approaches intended to elucidate the fullerene-formation mechanism are presented. The first of these involves pyrolytic synthesis of fullerenes from hydrocarbon ring structures known as polycyclic aromatic hydrocarbons (PAH's). Following work by Taylor et al. (Nature 366, 728, 1993), C60 is be made by heating a naphthalene vapor/argon mixture to approximately 1000°C. The use of several precursor P AH' s, including naphthalene, is examined in this work. The second approach involves the intentional poisoning of carbon-arc fullerene production by the addition of hydrogen (H₂) to the quenching atmosphere. By adding hydrogen in varying amounts one produces both PAH's and chain molecules, possibly representing interrupted steps of the pathway leading to fullerenes. Various analytical techniques are employed to examine both approaches. It is shown by mass spectrometry' that pyrolytic synthesis is not indicative of the fullerene-formation mechanism of the carbon-arc technique pioneered by Krlitschmer et al. (Nature 347, 354, 1990). In addition to mass spectrometry, Fourier-transform infrared and ultra-violet/visible absorption spectroscopy, high-performance Iiquidchromatography, and Raman-scattering spectroscopy are brought to bear in the analysis of the hydrogen-poisoning approach. From the analysis the PAH molecules formed in the hydrogen poisoning of the carbon-arc do not appear to comprise a pathway to fullerene formation. However, there is evidence indicating that chains, produced as a result of hydrogen contamination of the carbon-arc technique, are related to the formation of fullerene molecules.
Type:
text; Dissertation-Reproduction (electronic)
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Physics; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Huffman, Donald R.
Committee Chair:
Huffman, Donald R.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleTHE ROLE OF POLYCYCLIC AROMATIC HYDROCARBONS IN THE STUDY OF FULLERENE FORMATIONen_US
dc.creatorZumwalt, Michael Craneen_US
dc.contributor.authorZumwalt, Michael Craneen_US
dc.date.issued1995en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractTwo approaches intended to elucidate the fullerene-formation mechanism are presented. The first of these involves pyrolytic synthesis of fullerenes from hydrocarbon ring structures known as polycyclic aromatic hydrocarbons (PAH's). Following work by Taylor et al. (Nature 366, 728, 1993), C60 is be made by heating a naphthalene vapor/argon mixture to approximately 1000°C. The use of several precursor P AH' s, including naphthalene, is examined in this work. The second approach involves the intentional poisoning of carbon-arc fullerene production by the addition of hydrogen (H₂) to the quenching atmosphere. By adding hydrogen in varying amounts one produces both PAH's and chain molecules, possibly representing interrupted steps of the pathway leading to fullerenes. Various analytical techniques are employed to examine both approaches. It is shown by mass spectrometry' that pyrolytic synthesis is not indicative of the fullerene-formation mechanism of the carbon-arc technique pioneered by Krlitschmer et al. (Nature 347, 354, 1990). In addition to mass spectrometry, Fourier-transform infrared and ultra-violet/visible absorption spectroscopy, high-performance Iiquidchromatography, and Raman-scattering spectroscopy are brought to bear in the analysis of the hydrogen-poisoning approach. From the analysis the PAH molecules formed in the hydrogen poisoning of the carbon-arc do not appear to comprise a pathway to fullerene formation. However, there is evidence indicating that chains, produced as a result of hydrogen contamination of the carbon-arc technique, are related to the formation of fullerene molecules.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplinePhysicsen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorHuffman, Donald R.en_US
dc.contributor.chairHuffman, Donald R.en_US
dc.contributor.committeememberDenton, M. B.en_US
dc.contributor.committeememberParmenter, R. H.en_US
dc.identifier.proquest9620438en_US
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