Date of Award

5-2026

Degree Type

Masters Thesis

Degree Name

Master of Science (MS)

School

Polymer Science and Engineering

Committee Chair

Dr. Graham Collier

Committee Chair School

Polymer Science and Engineering

Committee Member 2

Dr. Derek Patton

Committee Member 2 School

Polymer Science and Engineering

Committee Member 3

Dr. Xiaodan Gu

Committee Member 4

None

Abstract

Organic electronic devices rely on the redox and charge transport properties of conjugated polymers. Many high-performance electroactive polymers are hydrophobic and require processing in organic solvents. As such, these materials are characterized in nonaqueous electrolyte systems to evaluate fundamental electrochemical properties such as onsets of oxidation, current densities, and doping kinetics. Supporting electrolytes and solvents are critical parameters in electrochemical characterization and through their modulation, can yield changes in these properties. Currently, research has been largely restricted to the investigation of ionic and solvent dependences in aqueous electrolyte-based systems. It is thus important to study how these fundamental properties are affected by the use of organic electrolytes dissolved in organic solvents. The techniques implemented to study this consisted of cyclic voltammetry (CV), spectroelectrochemistry, and scan rate dependence (SRD) experiments. A regiosymmetric propylenedioxythiophene-based polymer was used to prepare solid-state films to measure electrochemical responses based on systematically varying the electrolyte identity by cationic and anionic dependence, dissolved in acetonitrile (ACN) or propylene carbonate (PC). The influence of size and extent of solvation of electrolytes impacted redox responses. Generally, increased onsets of oxidation were measured as the size of the cation and anion increased. The increased polarity of PC led to larger concentrations of free ions in solution; however the increased viscosity resulted in diffusion-limitation kinetic responses above ~200 mV/s as measured by SRD experiments. Redox responses in ACN showed no such kinetic limitations up to 1000 mV/s. These results collectively demonstrate how fundamental redox responses of conjugated polymers can be modified by organic electrolytes systems.

Available for download on Monday, May 01, 2028

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