Chemistry at the glass transition: Fluorescence-detected proton transfer reactions

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dc.contributor.advisorCausgrove, Timothy P.
dc.contributor.authorGranfor, Keegan
dc.contributor.committeeMemberLarkin, Patrick
dc.contributor.committeeMemberAbdulla, Hussain
dc.date.accessioned2022-05-02T21:54:56Z
dc.date.available2022-05-02T21:54:56Z
dc.date.issued2019-05
dc.description.abstractMany liquids when cooled to cryogenic temperatures have the ability to take the form of a glassy substance; these are referred to as amorphous solids. As they are supercooled they do not form crystalline substances but rather an amorphous glass lacking in long-range structure. While the knowledge of these amorphous solids has been around for many years not much is known regarding the simplest physical and chemical processes that are allowed to occur within this glassy state. We introduce a new fluorescence-based temperature derivative spectroscopy methodology with the aim of discerning some of these physical and chemical attributes such as proton transfer in the glassy state. Proton transfer in a cryogenic sample is accomplished by exploiting the photolytic capabilities of o-nitrobenzaldehyde. When exposed to ultraviolet light, o-nitrobenzaldehyde is transformed to o-nitrosobenzoic acid which has a relatively large acid dissociation constant. Fluorescein, a simple fluorescent molecule, and o-nitrobenzaldehyde were dissolved in a glycerol/water mixture and cryogenically supercooled below the glass transition temperature. The sample was then exposed to ultraviolet light and measured fluorometrically for alterations in the spectra. This experiment was repeated at varying viscosities and with deuterated solvents for measuring isotopic effects. The spectra were fit to first-order rate kinetic Arrhenius style equations to determine the energy barriers associated with the proton transfer. Currently there is no documented use of temperature derivative spectroscopy using fluorometric based measurements to study dynamic processes and little if any information regarding simple chemical processes occurring within a supercooled glass sample. This research provides a more detailed picture of these processes as well as describe a new methodology for temperature derivative spectroscopic experimentsen_US
dc.description.collegeCollege of Science and Engineeringen_US
dc.description.departmentPhysical and Environmental Sciencesen_US
dc.format.extent45 pagesen_US
dc.identifier.urihttps://hdl.handle.net/1969.6/90535
dc.language.isoen_USen_US
dc.rightsThis material is made available for use in research, teaching, and private study, pursuant to U.S. Copyright law. The user assumes full responsibility for any use of the materials, including but not limited to, infringement of copyright and publication rights of reproduced materials. Any materials used should be fully credited with its source. All rights are reserved and retained regardless of current or future development or laws that may apply to fair use standards. Permission for publication of this material, in part or in full, must be secured with the author and/or publisher.en_US
dc.subjectFluorescenceen_US
dc.subjectGlass Transitionen_US
dc.subjectProton Transferen_US
dc.subjectTemperature Derivative Spectroscopyen_US
dc.titleChemistry at the glass transition: Fluorescence-detected proton transfer reactionsen_US
dc.typeTexten_US
dc.type.genreThesisen_US
thesis.degree.disciplineChemistryen_US
thesis.degree.grantorTexas A & M University--Corpus Christien_US
thesis.degree.levelMastersen_US
thesis.degree.nameMaster of Scienceen_US

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