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 Title: Luminescent Probes of Charge Transport in Modifying Layers on Electrodes Author(s): Zen, Jyh-Myng Doctoral Committee Chair(s): Faulkner, Larry, Department / Program: Chemistry Discipline: Chemistry Degree Granting Institution: University of Illinois at Urbana-Champaign Degree: Ph.D. Genre: Dissertation Subject(s): Chemistry, Analytical Abstract: The goals of this project are aimed at the investigation of charge transport among redox centers bound in polymer films on electrodes. Luminescent probes were used as an indicator of the charge transport process for the system of interest. The signals were then detected by spectroscopic methods. The advantage of spectroscopic methods is that they provide information about electrochemical systems which is not directly available in strictly electrochemical experiments.The energy transfer dynamics of the system of Ru(bpy)$\sb3\sp{2+}$ immobilized in poly(styrene sulfonate) film has been investigated. A relatively small amount of Co(bpy)$\sb3\sp{3+}$ was introduced into the system as a quencher to evaluate this value. Through this study, the ideas developed by Majda about the dynamics of the system were confirmed. The major conclusion is that the electron transport process is controlled by the counterion diffusion.A new approach based on photosensitization was proved to be effective in detection of i$\sb{\rm E}$ and D$\sb{\rm E}$ for polymer-modified electrodes. The study system was quaternized poly(vinylpyridine) with ferricyanide as redox centers. A rhodamine B isothiocyanate labeled poly(ethyleneimine) was constructed as the dye layer and hydroguinone was the supersensitizer. Different values of photocurrent were obtained by changing the intensity of the light source. One can extrapolate to infinite light intensity from the plot of 1/photocurrent vs. 1/light intensity to obtain a current equal to i$\sb{\rm E}$. The D$\sb{\rm E}$ was found to be in the order of 10$\sp{-8}$ cm$\sp2$/sec, and are in the neighborhood of that measured by steady-state voltammetry of the same experimental system. Issue Date: 1988 Type: Text Description: 146 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1988. URI: http://hdl.handle.net/2142/70417 Other Identifier(s): (UMI)AAI8823299 Date Available in IDEALS: 2014-12-15 Date Deposited: 1988
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