Polyaromatic Cores for Enhanced Conductivity in Inherently Conductive Polymers (ICPs)
The discovery of Inherently Conductive Polymers (ICPs), also known as “synthetic metals”, is an attracting class of materials as a promising alternative for metallic semiconductors and conductors, which combine the positive properties of metals and conventional polymers with ease of synthesis and flexible processing techniques. These polymers are useful for energy storage, electrochromics, corrosion protection, thermoelectric materials, chemical and biomedical sensors, and so on. Despite the excellent electrical conductivity along the length of each conjugated chain of ICPs, the electron hopping required for conduction from chain to chain results in series resistance. The hypothesis of this thesis is that the electron hopping can be minimized by providing alternative conjugated pathways in the ICPs using a variety of polyaromatic cores. Starting from a model compound, a tetrafunctionalized pyrene novel monomer was designed and synthesized using a pyrene core coupled with 3,4-ethylenedioxythiophene (EDOT) via vinylene linkages using the Horner-Wadsworth-Emmons (HWE) reaction. Characterizations confirmed the monomer, from which several polymers were prepared via both oxidative chemical polymerization and electropolymerization. The conductivity of the resulting polymers was investigated using four-point collinear probe. The same technique can be applied to generate graphene-based hyperbranched ICPs. The functionalized graphene hub with aldehyde groups on the edges (graphenal) can be coupled with EDOT to yield a hyperfunctionalized monomer that can be polymerized to form a highly conjugated network with enhanced conductivity.
Conductive polymers, Polyaromatic cores, 3,4-ethylenedioxythiophene, Pyrene, Functionalized graphene
Wang, X. (2017). <i>Polyaromatic cores for enhanced conductivity in Inherently Conductive Polymers (ICPs)</i> (Unpublished thesis). Texas State University, San Marcos, Texas.