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Pyrrole-Based Conductive Polymer Composites for Electroanalysis and Chemical Separations

Devasurendra, Amila Manuradha
http://rave.ohiolink.edu/etdc/view?acc_num=toledo1513257195906402

Abstract Details

2017, Doctor of Philosophy, University of Toledo, Chemistry.
Conducting polymers (CPs) epitomize an interesting group of organic materials which possess electrical conducting ability. After the discovery of halogen derivatives of poly(acetylene) by Shirakawa, MacDiarmid and Heeger in 1977 and later receiving the Nobel prize for chemistry in 2000 for the same invention, CPs gained tremendous attention from the scientific community. Different monomers such as pyrrole, thiophene, aniline and their derivatives have been commonly employed for the preparation of CPs. This dissertation research was primarily focused on the use of pyrrole and several derivatives to fabricate CP composites as thin films for electroanalytical and chemical separation applications. The first chapter of this dissertation begins with an introduction to CPs and their synthesis protocols. An overview of techniques and applications of CPs with a literature review are also described later as a foundation for the discussions in following chapters. In the second chapter, an electroanalytical application of CPs is discussed. A modified glassy carbon (GCE) electrode was developed by entrapping pyrroloquinoline quinone (PQQ) and oxidized single wall carbon nanotubes (Ox-SWNT) into a gold-polypyrrole (Au-PPy) nanocomposite matrix for the amperometric detection of biological thiols. Optimum conditions were then determined and the modified electrode was utilized for quantification of several representative biological thiols. Excellent limit of detections (LODs) with good linear response were achieved. The approach utilized to fabricate the electrode, consumed minimum amount of catalyst materials (PQQ and Ox-SWNT) without scarificing the stability or the sensitivity of the detection. As chapter three describes, pyrrole was covalently bonded to different imidazolium ionic liquids via an N-substituted alkyl linkage to prepare electropolymerizable conductive polymeric ionic liquid (CPIL) monomers. Preliminary characterization of the CPIL monomers indicated that the monomer with a methyl imidazole head group had the highest thermal stability. Once electropolymerized, it demonstrated selective uptake of anionic species while rejecting the cationic species in the solution. Further, CPIL was coated on Pt microwires with and without doping of single-wall carbon nanotubes (SWNT). Coatings deposited with SWNT doping showed a significant increase in coating thickness compared to pristine polymer with excellent fiber-to-fiber reproducibility. Application of these new CPIL/SWNT coated fibers in solid-phase microextraction (SPME) followed by gas chromatography detection afforded selective extraction of organic aromatic analytes. When normalized for film thickness, the new coating demonstrated improved extraction efficiency compared to commercial polydimethylsiloxane (PDMS) fibers. In the chapter four, an application of CP composite in solid-phase extraction (SPE) is explained. To accomplish that, a PPy nanocomposite sorbent material was successfully coated on silica particles. After characterization, a solid-phase extraction (SPE) cartridge was packed with new material for extraction of microcystins (MCs). Experimental parameters were then optimized for different aqueous sample matrices, including HPLC-grade, lake, and tap water. With optimized conditions, MCs were determined by liquid chromatography-mass spectrometry (LC-MS). Excellent average recoveries for all MCs in three water sample matrices were achieved with low relative standard deviations (RSDs), which indicated outstanding efficiency and reproducibility. Importantly, calculated LODs and limits of quantification (LOQs) were well below the current United States EPA and World Health Organization recommended guidelines. Cartridges prepared were reusable for at least three times. Moreover, selective extraction of more hydrophilic vs. more hydrophobic MCs was also achieved.
Jon Kirchhoff, PhD (Advisor)
195 p.
Chemistry

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Citations

  • Devasurendra, A. M. (2017). Pyrrole-Based Conductive Polymer Composites for Electroanalysis and Chemical Separations [Doctoral dissertation, University of Toledo]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1513257195906402

    APA Style (7th edition)

  • Devasurendra, Amila. Pyrrole-Based Conductive Polymer Composites for Electroanalysis and Chemical Separations. 2017. University of Toledo, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=toledo1513257195906402.

    MLA Style (8th edition)

  • Devasurendra, Amila. "Pyrrole-Based Conductive Polymer Composites for Electroanalysis and Chemical Separations." Doctoral dissertation, University of Toledo, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1513257195906402

    Chicago Manual of Style (17th edition)

toledo1513257195906402
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This open access ETD is published by University of Toledo and OhioLINK.