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|Title:||Polymer Coated Electrodes as Microelectrochemical Media|
|Author(s):||Good, Nancy Linden|
|Department / Program:||Chemistry|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Abstract:||Gold film electrodes were coated with polymer films less than 1000 (ANGSTROM) thick, then electrochemistry was done on samples absorbed into the film from solution. Detailed studies of potassium ferricyanide in a poly(4-vinyl pyridine) film showed that cyclic voltammetry can indeed be done successfully with this system.
The performance of the electrode from the viewpoints of both analytical chemistry and electrochemistry has been measured. An interesting property of the cationic polyelectrolyte is its selectivity, favoring multiply charged anions. In the case of ferricyanide, 5 x 10('-10) moles can be absorbed from a 10('-4) M solution, and most remain in the film even if the electrode is transferred to an electrolyte solution containing no ferricyanide. Very roughly, 10% of the pyridine groups of the polymer are associated with a ferricyanide ion.
Monitoring the cyclic voltammograms as the pH of the solution is varied from 7 to 1 leads to some knowledge of the environment within the film. At low pH, where the polymer should be positively charged, near-theoretical peak shapes for reactants and products bound to electrode surfaces are observed. Therefore the structure of the film does not appear to retard mass transport on the timescale of the experiments, with 50 mV/sec scan rates.
Some preliminary work with providing multiple identical electrodes on a single glass slide has been done, and future applications to analytical chemistry are discussed. Lack of an effective reference electrode prevented development of an entire electrochemical cell on a polymer-coated slide, but some progress was made and further experiments are suggested.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1981.
|Date Available in IDEALS:||2014-12-13|