UBC Theses and Dissertations
The electrochemical properties of conducting polymers for energy storage applications Bremner, Glen
The synthesis and characterization of oligothiophene-capped Au and Cu nanoparticles (NPs) are reported. Homo- and co-polymer films of these NPs were prepared electrochemically and studied using cyclic voltammetry, electron microscopy, and absorption and emission spectroscopies. The Au NPs were capped by either 3'-thiol-substituted terthiophene (1) or 3'-phosphine-substituted terthiophene (2). The electrochemical oxidation of 1-capped Au NPs (4) resulted in a polymeric film which displayed good electroactivity whereas attempted electropolymerization of 2-capped Au NPs (5) was unsuccessful. Exposing the poly(4) films to an iodide/triiodide solution lead to etching of the Au and a decrease in the electroactivity of the polymer. A hybrid copolymer was formed by electropolymerizing ethylenedioxythiophene in solution with 4 (PEDOT-4). It was found that it was possible to selectively etch Au from PEDOT-4 films to yield porous PEDOT films, which were analyzed using elemental analysis methods and electron microscopy. The films after etching showed slightly improved charging and discharging kinetics, suggestive of improved ionic diffusion in the polymer. Cu NPs capped by 1 (7) were electrochemically oxidized to form a polymer film. The lower oxidation potential of 7 relative to 4 allowed for the formation of crystalline regions in the polymer film, and exhibited the characteristic XRD peaks of Cu (0). PEDOT-7 films were prepared which showed enhanced electroactivity over pure PEDOT films. An azidostyrylthiophene compound (9) was synthesized and was shown to be both thermally and photochemically reactive. PEDOT-9 copolymers were prepared and studied using cyclic voltammetry. Irradiation of the PEDOT-9 films show improved charging / discharging kinetics due to crosslinking of the polymer film by the reactive azide substituent.
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Attribution-NonCommercial-NoDerivs 2.5 Canada