Surface Modification of Carbon Nanotubes with Conjugated Polyelectrolytes: Fundamental Interactions and Applications in Composite Materials, Nanofibers, Electronics, and Photovoltaics

Handle URI:
http://hdl.handle.net/10754/582475
Title:
Surface Modification of Carbon Nanotubes with Conjugated Polyelectrolytes: Fundamental Interactions and Applications in Composite Materials, Nanofibers, Electronics, and Photovoltaics
Authors:
Ezzeddine, Alaa ( 0000-0002-0983-8956 )
Abstract:
Ever since their discovery, Carbon nanotubes (CNTs) have been renowned to be potential candidates for a variety of applications. Nevertheless, the difficulties accompanied with their dispersion and poor solubility in various solvents have hindered CNTs potential applications. As a result, studies have been developed to address the dispersion problem. The solution is in modifying the surfaces of the nanotubes covalently or non-covalently with a desired dispersant. Various materials have been employed for this purpose out of which polymers are the most common. Non-covalent functionalization of CNTs via polymer wrapping represents an attractive method to obtain a stable and homogenous CNTs dispersion. This method is able to change the surface properties of the nanotubes without destroying their intrinsic structure and preserving their properties. This thesis explores and studies the surface modification and solublization of pristine single and multiwalled carbon nanotubes via a simple solution mixing technique through non-covalent interactions of CNTs with various anionic and cationic conjugated polyelectrolytes (CPEs). The work includes studying the interaction of various poly(phenylene ethynylene) electrolytes with MWCNTs and an imidazolium functionalized poly(3-hexylthiophene) with SWCNTs. Our work here focuses on the noncovalent modifications of carbon nanotubes using novel CPEs in order to use these resulting CPE/CNT complexes in various applications. Upon modifying the CNTs with the CPEs, the resulting CPE/CNT complex has been proven to be easily dispersed in various organic and aqueous solution with excellent homogeneity and stability for several months. This complex was then used as a nanofiller and was dispersed in another polymer matrix (poly(methyl methacrylate), PMMA). The PMMA/CPE/CNT composite materials were cast or electrospun depending on their desired application. The presence of the CPE modified CNTs in the polymer matrix has been proven to enhance the composites thermal, mechanical and electrical properties compared to pristine CNTs. Various spectroscopic and microscopic techniques such as UV-vis, fluorescence, TEM, AFM and SEM were used to study and characterize the CPE/CNT complexes. Also, TGA, DSC and DMA were used to study the thermal and mechanical properties of the composite materials. Our current work represents a fundamental study on the non-covalent interactions between CNTs and CPEs on one hand and gives a real life example on the CPE/CNT application in composite materials and electronics.
Advisors:
khashab, niveen ( 0000-0003-2728-0666 )
Committee Member:
Hadjichristidis, Nikolaos ( 0000-0003-1442-1714 ) ; lubineau, gilles ( 0000-0002-7370-6093 ) ; Schanze, Kirk ( 0000-0003-3342-4080 )
KAUST Department:
Physical Sciences and Engineering (PSE) Division; Chemical Science Program
Program:
Chemical Sciences
Issue Date:
Oct-2015
Type:
Dissertation
Appears in Collections:
Dissertations; Physical Sciences and Engineering (PSE) Division; Chemical Science Program

Full metadata record

DC FieldValue Language
dc.contributor.advisorkhashab, niveenen
dc.contributor.authorEzzeddine, Alaaen
dc.date.accessioned2015-11-22T05:47:58Zen
dc.date.available2015-11-22T05:47:58Zen
dc.date.issued2015-10en
dc.identifier.urihttp://hdl.handle.net/10754/582475en
dc.description.abstractEver since their discovery, Carbon nanotubes (CNTs) have been renowned to be potential candidates for a variety of applications. Nevertheless, the difficulties accompanied with their dispersion and poor solubility in various solvents have hindered CNTs potential applications. As a result, studies have been developed to address the dispersion problem. The solution is in modifying the surfaces of the nanotubes covalently or non-covalently with a desired dispersant. Various materials have been employed for this purpose out of which polymers are the most common. Non-covalent functionalization of CNTs via polymer wrapping represents an attractive method to obtain a stable and homogenous CNTs dispersion. This method is able to change the surface properties of the nanotubes without destroying their intrinsic structure and preserving their properties. This thesis explores and studies the surface modification and solublization of pristine single and multiwalled carbon nanotubes via a simple solution mixing technique through non-covalent interactions of CNTs with various anionic and cationic conjugated polyelectrolytes (CPEs). The work includes studying the interaction of various poly(phenylene ethynylene) electrolytes with MWCNTs and an imidazolium functionalized poly(3-hexylthiophene) with SWCNTs. Our work here focuses on the noncovalent modifications of carbon nanotubes using novel CPEs in order to use these resulting CPE/CNT complexes in various applications. Upon modifying the CNTs with the CPEs, the resulting CPE/CNT complex has been proven to be easily dispersed in various organic and aqueous solution with excellent homogeneity and stability for several months. This complex was then used as a nanofiller and was dispersed in another polymer matrix (poly(methyl methacrylate), PMMA). The PMMA/CPE/CNT composite materials were cast or electrospun depending on their desired application. The presence of the CPE modified CNTs in the polymer matrix has been proven to enhance the composites thermal, mechanical and electrical properties compared to pristine CNTs. Various spectroscopic and microscopic techniques such as UV-vis, fluorescence, TEM, AFM and SEM were used to study and characterize the CPE/CNT complexes. Also, TGA, DSC and DMA were used to study the thermal and mechanical properties of the composite materials. Our current work represents a fundamental study on the non-covalent interactions between CNTs and CPEs on one hand and gives a real life example on the CPE/CNT application in composite materials and electronics.en
dc.language.isoenen
dc.subjectmultiwall carbon nanotubes (MWCNTs)en
dc.subjectConjugated polyelectrolytes (CPEs)en
dc.subjectPoly(methyl methacrylate) (PMMA)en
dc.subjectDispersionen
dc.subjectElectrical conductivityen
dc.subjectCompositesen
dc.titleSurface Modification of Carbon Nanotubes with Conjugated Polyelectrolytes: Fundamental Interactions and Applications in Composite Materials, Nanofibers, Electronics, and Photovoltaicsen
dc.typeDissertationen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentChemical Science Programen
thesis.degree.grantorKing Abdullah University of Science and Technologyen_GB
dc.contributor.committeememberHadjichristidis, Nikolaosen
dc.contributor.committeememberlubineau, gillesen
dc.contributor.committeememberSchanze, Kirken
thesis.degree.disciplineChemical Sciencesen
thesis.degree.nameDoctor of Philosophyen
dc.person.id124188en
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