Surface Engineering and Synthesis of Graphene and Fullerene Based Nanostructures

Persistent Link:
http://hdl.handle.net/10150/605216
Title:
Surface Engineering and Synthesis of Graphene and Fullerene Based Nanostructures
Author:
Gnanaprakasa, Tony Jefferson
Issue Date:
2016
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.
Embargo:
Release 04-Jan-2017
Abstract:
Graphene is a two-dimensional carbon structure that exhibits remarkable structure-property relations. Consequently, there has been immense effort undertaken towards developing methods for graphene synthesis. Chemical vapor deposition (CVD) and chemical exfoliation from colloidal suspensions are two common methods used for obtaining graphene films. However, the underlying experimental conditions have to be carefully optimized in order to obtain graphene films of controllable thickness and morphology. In this context, a significant part of this dissertation was devoted towards developing and improving current CVD-based and chemical exfoliation based methods for synthesizing high quality graphene films. Specifically, in the CVD based procedure for growing graphene on copper, the effect of surface pretreatment of copper was investigated and the quality of graphene grown using two different pretreatment procedures was compared and analyzed. In particular, graphene grown on electropolished copper (EP-Cu) was analyzed with respect to its surface morphology, surface roughness and thickness, and compared with graphene grown on as cold-rolled acetic acid cleaned copper (AA-Cu). It was shown that electropolishing of the Cu substrates prior to graphene growth greatly enhanced the ability to obtain flat, uniform, predominantly single layer graphene surface coverage on copper. The reported surface roughness of the graphene on EP-Cu was found to be much lower than for previously reported systems, suggesting that the electropolishing procedure adopted in this work has great promise as a pretreatment step for Cu substrates used in CVD growth of graphene. Obtaining graphene from colloidal suspensions of graphitic systems was also examined. In this work, an acid (H₂SO₄ + HNO₃) treatment process for intercalating natural graphite flakes was examined and the ability to reversibly intercalate and deintercalate acid ions within graphitic galleries was investigated. More importantly, a rapid-thermal expansion (RTP) processing was developed to thermally expand the acid-treated graphite, followed by exfoliation of predominantly bilayer graphene as well as few layer graphene flakes in an organic solvent (N, N-Dimethylformamide - DMF). The developed method was shown to provide bilayer and few layer graphene flakes in a reliable fashion. Fullerene is another carbon nanostructure that has garnered attention due to unique structure and chemical properties. Recently, there has been increased focus towards harnessing the properties of fullerenes by synthesizing fullerene self-assemblies in the form of extended rods, tubes and more complex shapes. Current methods to synthesize these self-assemblies are either cumbersome, time consuming or expensive. In this context, an alternate, straightforward dip-coating procedure technique to self-assemble equal-sized, faceted, polymerized fullerene nanorods on graphene-based substrates in a rapid fashion was developed. By suitably modifying the kinetics of self-assembly, the ability to reliably control the spatial distribution, size, shape, morphology and chemistry of fullerene nanorods was achieved.
Type:
text; Electronic Dissertation
Keywords:
Fullerene based Superstructures; Graphene; Graphite Intercalation Compounds - Intercalation Chemistry; Self-assembly of Nanomaterials; Synthesis of Carbon Nanostructures; Materials Science & Engineering; Chemical Vapor Deposition
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Materials Science & Engineering
Degree Grantor:
University of Arizona
Advisor:
Muralidharan, Krishna; Raghavan, Srini

Full metadata record

DC FieldValue Language
dc.language.isoen_USen
dc.titleSurface Engineering and Synthesis of Graphene and Fullerene Based Nanostructuresen_US
dc.creatorGnanaprakasa, Tony Jeffersonen
dc.contributor.authorGnanaprakasa, Tony Jeffersonen
dc.date.issued2016en
dc.publisherThe University of Arizona.en
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
dc.description.releaseRelease 04-Jan-2017en
dc.description.abstractGraphene is a two-dimensional carbon structure that exhibits remarkable structure-property relations. Consequently, there has been immense effort undertaken towards developing methods for graphene synthesis. Chemical vapor deposition (CVD) and chemical exfoliation from colloidal suspensions are two common methods used for obtaining graphene films. However, the underlying experimental conditions have to be carefully optimized in order to obtain graphene films of controllable thickness and morphology. In this context, a significant part of this dissertation was devoted towards developing and improving current CVD-based and chemical exfoliation based methods for synthesizing high quality graphene films. Specifically, in the CVD based procedure for growing graphene on copper, the effect of surface pretreatment of copper was investigated and the quality of graphene grown using two different pretreatment procedures was compared and analyzed. In particular, graphene grown on electropolished copper (EP-Cu) was analyzed with respect to its surface morphology, surface roughness and thickness, and compared with graphene grown on as cold-rolled acetic acid cleaned copper (AA-Cu). It was shown that electropolishing of the Cu substrates prior to graphene growth greatly enhanced the ability to obtain flat, uniform, predominantly single layer graphene surface coverage on copper. The reported surface roughness of the graphene on EP-Cu was found to be much lower than for previously reported systems, suggesting that the electropolishing procedure adopted in this work has great promise as a pretreatment step for Cu substrates used in CVD growth of graphene. Obtaining graphene from colloidal suspensions of graphitic systems was also examined. In this work, an acid (H₂SO₄ + HNO₃) treatment process for intercalating natural graphite flakes was examined and the ability to reversibly intercalate and deintercalate acid ions within graphitic galleries was investigated. More importantly, a rapid-thermal expansion (RTP) processing was developed to thermally expand the acid-treated graphite, followed by exfoliation of predominantly bilayer graphene as well as few layer graphene flakes in an organic solvent (N, N-Dimethylformamide - DMF). The developed method was shown to provide bilayer and few layer graphene flakes in a reliable fashion. Fullerene is another carbon nanostructure that has garnered attention due to unique structure and chemical properties. Recently, there has been increased focus towards harnessing the properties of fullerenes by synthesizing fullerene self-assemblies in the form of extended rods, tubes and more complex shapes. Current methods to synthesize these self-assemblies are either cumbersome, time consuming or expensive. In this context, an alternate, straightforward dip-coating procedure technique to self-assemble equal-sized, faceted, polymerized fullerene nanorods on graphene-based substrates in a rapid fashion was developed. By suitably modifying the kinetics of self-assembly, the ability to reliably control the spatial distribution, size, shape, morphology and chemistry of fullerene nanorods was achieved.en
dc.typetexten
dc.typeElectronic Dissertationen
dc.subjectFullerene based Superstructuresen
dc.subjectGrapheneen
dc.subjectGraphite Intercalation Compounds - Intercalation Chemistryen
dc.subjectSelf-assembly of Nanomaterialsen
dc.subjectSynthesis of Carbon Nanostructuresen
dc.subjectMaterials Science & Engineeringen
dc.subjectChemical Vapor Depositionen
thesis.degree.namePh.D.en
thesis.degree.leveldoctoralen
thesis.degree.disciplineGraduate Collegeen
thesis.degree.disciplineMaterials Science & Engineeringen
thesis.degree.grantorUniversity of Arizonaen
dc.contributor.advisorMuralidharan, Krishnaen
dc.contributor.advisorRaghavan, Srinien
dc.contributor.committeememberMuralidharan, Krishnaen
dc.contributor.committeememberRaghavan, Srinien
dc.contributor.committeememberBeck, Warren J.en
dc.contributor.committeememberPotter, Barrett G., Jr.en
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