Preparation and characterization of polymer composites containing gold nanoparticles

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buir.advisorSüzer, Şefik
dc.contributor.authorYılmaz, Eda
dc.date.accessioned2016-01-08T18:15:25Z
dc.date.available2016-01-08T18:15:25Z
dc.date.issued2011
dc.descriptionAnkara : The Department of Chemistry and the Graduate School of Engineering and Science of Bilkent University, 2011.en_US
dc.descriptionThesis (Ph. D.) -- Bilkent University, 2011.en_US
dc.descriptionIncludes bibliographical references leaves 77-84.en_US
dc.description.abstractIn this study, light-assisted synthesis of gold nanoparticles in polymer films is demonstrated and characterization of gold nanoparticle-polymer composites using various techniques is shown. There are various methods introduced for the synthesis of gold nanoparticles in solution and their integration to the polymer films afterwards. However, synthesizing gold nanoparticles directly inside the polymer matrix is more advantageous for the production of polymer-nanoparticle composites. An advantage of synthesizing gold nanoparticles within polymer films is the opportunity of photo-patterning. Films having patterns made of regions with and without gold nanoparticles can be produced, using masks designed to cut off the radiation at desired places. Such patterned films were investigated with scanning electron microscope (SEM) and dark regions between irradiated regions and masked regions were observed. These dark regions are shown to be “ion depleted regions”, where gold ions diffuse through irradiated regions during the irradiation. These regions of about 10 m width, suggests a very large distance for gold ions to diffuse through a rigid matrix like Poly(methyl methacrylate)(PMMA), which is very interesting. Supporting evidence for the existence of these regions was obtained from fluorescence studies with Rhodamine 6G molecule and x-ray electron spectroscopy (XPS). The observations made through the formation of ion depleted regions can be used to estimate the diffusion constant of gold ions inside the PMMA matrix. Also the presence of ion depleted regions indicate the stability of photo-patterns created on the polymer film against smearing during light exposure after the production, by setting an upper limit to the critical feature size. During the characterization of gold nanoparticle-polymer composites, the electrical properties of PMMA with and without gold nanoparticles were investigated using charge resolved XPS, while applying external bias to the films with and without gold nanoparticles to probe the charging properties of the films. An enhancement of conductivity of PMMA films containing gold nanoparticles was observed using this technique. Additionally charge resolved XPS technique was also used to determine the charge storage characteristics of the polymer surfaces, which is important for the identification of charging mechanisms during contact and other electrification processes. It was shown that the PMMA surface is very susceptible to negative charging and even native negative charges on the PMMA surface can be observed prior to any treatment. Also when the surface is charged carbon and oxygen atoms of the carbonyl and methoxy groups of PMMA were observed to behave differently from the backbone of the polymer, which shows the chemical specificity of the charge accumulating spots on the surface.en_US
dc.description.provenanceMade available in DSpace on 2016-01-08T18:15:25Z (GMT). No. of bitstreams: 1 0005083.pdf: 3238584 bytes, checksum: 57bd5e6776fd62b1d3ef2aef11a787f6 (MD5)en
dc.description.statementofresponsibilityYılmaz, Edaen_US
dc.format.extentxiv, 84 leaves, illustrationsen_US
dc.identifier.itemidB120275
dc.identifier.urihttp://hdl.handle.net/11693/15238
dc.language.isoEnglishen_US
dc.rightsinfo:eu-repo/semantics/openAccessen_US
dc.subjectGold nanoparticleen_US
dc.subjectPMMAen_US
dc.subjectXPSen_US
dc.subjectCharge resolved XPSen_US
dc.subjectPhoto-patterningen_US
dc.subjectContact electrificationen_US
dc.subjectIon depleted regionen_US
dc.subject.lccTA418.9.C6 Y55 2011en_US
dc.subject.lcshPolymeric composites.en_US
dc.subject.lcshNanostructured materials.en_US
dc.subject.lcshNanoparticles.en_US
dc.titlePreparation and characterization of polymer composites containing gold nanoparticlesen_US
dc.typeThesisen_US
thesis.degree.disciplineChemistry
thesis.degree.grantorBilkent University
thesis.degree.levelDoctoral
thesis.degree.namePh.D. (Doctor of Philosophy)

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