Date of Graduation

Fall 12-14-2018

Document Type

Thesis

Degree Name

Master of Science in Chemistry

College/School

College of Arts and Sciences

Department/Program

Chemistry

First Advisor

Ryan M. West, Ph.D.

Second Advisor

William Melaugh, Ph.D.

Third Advisor

Janet G. Yang Ph.D.

Abstract

In this work, ferricyanide-doped polyaniline (PANI) is electropolymerized by constant current and cyclic voltammetry (CV) measurements with simultaneous monitoring of mass changes using electrochemical quartz crystal microbalance (eQCM). Raman spectroscopy, Fourier transform infrared spectroscopy and CV measurements confirm the incorporation of the ferricyanide into the film and indicate modified electrical conductivity. UV-Vis absorbance spectroscopy and Raman spectroscopy confirm the conducting ‘emeraldine-salt’ state and confirm the presence of polarons, i.e. charge carriers.

The addition of ferricyanide during electropolymerization of the PANI film results in an increase of polymerization rate as confirmed using eQCM. A decrease in counter ion ingress/egress and an inverted mass transport behavior is observed during simultaneous CV and eQCM measurements in background electrolyte, suggesting a cation-exchange mechanism for maintaining charge neutrality during oxidation of the polymer. To our knowledge, cation exchanging PANI films, as synthesized here, have not been previously reported.

Additionally, the relationship between the identity and charge of the added transition metal complexes, the polymerization rate, and the film properties are studied by addition of potassium hexacyanoruthenate(II), FeCl3 and RuCl3 to the polymerization solution. The presence of potassium hexacyanoruthenate(II)enhances the polymerization rate and alters the electrochemical behavior, much like ferricyanide, while FeCl3 and RuCl3 do not induce such an effect.

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