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dc.contributor.advisorSaavedra, S. Scotten_US
dc.contributor.advisorArmstrong, Neal R.en_US
dc.contributor.authorDoherty, Walter Johnen_US
dc.creatorDoherty, Walter Johnen_US
dc.date.accessioned2011-12-06T14:02:27Z
dc.date.available2011-12-06T14:02:27Z
dc.date.issued2005en_US
dc.identifier.urihttp://hdl.handle.net/10150/195671
dc.description.abstractThis research focuses on the development of spectroelectrochemical sensor formats based on thin film molecular architectures and electrochemical detection of sol-gel encapsulated macromolecular recognition elements. To achieve this goal, there were two major objectives: 1) to demonstrate and characterize conductive polymer grown electrochemically in porous sol-gel thin films with specific regard to the ability of the polymer to mediate charge transfer between sol-gel encapsulated molecules and the electrode surface, and 2) to develop a means to probe the spectroscopic properties of highly absorbent thin films as a function of applied potential. Toward the first objective, diffusion of a derivatized thiophene monomer into a sol-gel thin film and subsequent electropolymerization at an underlying indium-tin oxide (ITO) surface was found to produce a conductive network of polymer capable of mediating electron transfer from encapsulated redox centers in the bulk of the sol-gel film to the electrode surface. At high levels of polymer loading, emergent, sol-gel templated, polymeric structures are formed which extend from the sol-gel surface into the electrolyte solution and exhibit electrochemical properties of ultramicroelectrode arrays. To achieve the second objective, a polychromatic, electroactive attenuated total internal reflectance (EA-ATR) instrument was developed consisting of an indium-tin oxide (ITO) coated glass internal reflection element (IRE). In addition to a high degree of surface sensitivity relative to transmission geometries, this geometry affords acquisition of absorption anisotropy information, via polarization of the incident beam, to determine the orientation distribution in molecular adlayers. To demonstrate these abilities, the orientational distribution of monolayer and bilayer films of perylene and copper phthalocyanine derivatives, respectively, was determined. Furthermore, it was demonstrated that the EA-ATR could be used in a potential-modulated mode (PM-ATR) to study the kinetics of electro-optical switching in conductive copolymer thin films.
dc.language.isoenen_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.subjectspectroscopyen_US
dc.subjectelectrochemistryen_US
dc.subjectconductive polymeren_US
dc.subjectmolecular orientationen_US
dc.subjectsol-gelen_US
dc.subjectthin filmen_US
dc.titlePOLYMER-MEDIATED ELECTROCHEMISTRY IN SOL-GEL THIN FILMS AND SPECTROELECTROCHEMICAL CHARACTERIZATION OF MOLECULAR ADLAYERS ON INDIUM-TIN OXIDE ELECTRODE SURFACESen_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.contributor.chairSaavedra, S. Scotten_US
dc.identifier.oclc137354515en_US
thesis.degree.grantorUniversity of Arizonaen_US
thesis.degree.leveldoctoralen_US
dc.contributor.committeememberArmstrong, Neal R.en_US
dc.contributor.committeememberDenton, M. Bonneren_US
dc.contributor.committeememberMcGrath, Dominic V.en_US
dc.contributor.committeememberZheng, Zhipingen_US
dc.identifier.proquest1233en_US
thesis.degree.disciplineChemistryen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.namePh.D.en_US
refterms.dateFOA2018-06-16T13:05:54Z
html.description.abstractThis research focuses on the development of spectroelectrochemical sensor formats based on thin film molecular architectures and electrochemical detection of sol-gel encapsulated macromolecular recognition elements. To achieve this goal, there were two major objectives: 1) to demonstrate and characterize conductive polymer grown electrochemically in porous sol-gel thin films with specific regard to the ability of the polymer to mediate charge transfer between sol-gel encapsulated molecules and the electrode surface, and 2) to develop a means to probe the spectroscopic properties of highly absorbent thin films as a function of applied potential. Toward the first objective, diffusion of a derivatized thiophene monomer into a sol-gel thin film and subsequent electropolymerization at an underlying indium-tin oxide (ITO) surface was found to produce a conductive network of polymer capable of mediating electron transfer from encapsulated redox centers in the bulk of the sol-gel film to the electrode surface. At high levels of polymer loading, emergent, sol-gel templated, polymeric structures are formed which extend from the sol-gel surface into the electrolyte solution and exhibit electrochemical properties of ultramicroelectrode arrays. To achieve the second objective, a polychromatic, electroactive attenuated total internal reflectance (EA-ATR) instrument was developed consisting of an indium-tin oxide (ITO) coated glass internal reflection element (IRE). In addition to a high degree of surface sensitivity relative to transmission geometries, this geometry affords acquisition of absorption anisotropy information, via polarization of the incident beam, to determine the orientation distribution in molecular adlayers. To demonstrate these abilities, the orientational distribution of monolayer and bilayer films of perylene and copper phthalocyanine derivatives, respectively, was determined. Furthermore, it was demonstrated that the EA-ATR could be used in a potential-modulated mode (PM-ATR) to study the kinetics of electro-optical switching in conductive copolymer thin films.


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