There is no abstract available for this dissertation.

A series of 12-, 13-, and 14-membered crown ether rings bearing polymerisable side-chains has been synthesised. The crown ethers were attached to a methacrylate or acrylate polymerisable group either via a short link (Ring-CH(_2)-O-Polymer) or via a spacer group. Both hydrocarbon and ethylene oxide spacer groups were used, giving structures of the form (Ring-CH(_2)-O-(CH(_2))(_6)-O-Polymer) and (Ring-CH(_2)-O-((CH(_2)CH(_2))(_2)O)-Polymer). The ethylene oxide chain can potentially bind to a Li(^+) dopant ion. The relative Li(+) binding affinity of 12-, 13-, and 14-membered mono- and disubstituted crown ethers has been assessed by variable temperature (^13)c and (^7)Li NMR. The crown ether bearing monomers were polymerised using standard free-radical polymerisation methods to yield amorphous materials whose glass transition temperature (T(_g)) was controlled principally by the nature of the spacer group. On doping with lithium triflate (LiCF(_3)SO(_3)), the polymers exhibit high ionic conductivity. The conductivity was primarily dependent on polymer T(_g), but was also found to be higher for 12-crown-4 based systems than for 13-crown-4 and 14-crown-4 based analogues. This behaviour was consistent with the results of the NMR studies, which showed that Li(^+) exchange occurs more readily between 12-crown-4 rings than 13- or 14-crown-4 rings. The NMR studies also showed that 12-crown-4 systems have a higher tendency to form 2:1 (ring : Li(^+)) complexes. Within a polymer matrix, the presence of 2:1 complexes allows Li(^+) migration via an association-disassociation mechanism, avoiding the high energy intermediate state of a free or weakly bound Li(^+) ion. The greater encapsulation provided by 2:1 complexation may also aid in ion pair separation.

ABSTRACT SYNTHESIS AND CHARACTERIZATION OF THIOPHEN-3-YL ACETIC ACID 4-PYRROL-1-YL PHENYL ESTER AND ITS CONDUCTING POLYMERS Bing&ouml / l, Bahar M.Sc., Department of Chemistry Supervisor: Prof. Dr. Levent Toppare November 2003, 54 pages Thiophen-3-yl acetic acid 4-pyrrol-1-yl phenyl ester (TAPE) monomer was synthesized by the reaction of thiophene acetic acid with thionyl chloride, and further reaction of thiophen-3-yl-acetyl chloride with 4-pyrrol-1-yl phenol. Electrochemical behavior of this monomer (TAPE) was determined by cyclic voltammetry. Homopolymers were achieved both by using electrochemical and chemical polymerization techniques. Copolymers of TAPE in the presence of bithiophene and pyrrole were synthesized by potentiostatic electrochemical polymerization in acetonitrile-tetrabutylammonium tetrafluoroborate (TBAFB) solvent-electrolyte couple. The chemical structures were confirmed both by Nuclear Magnetic Resonance Spectroscopy (NMR) and Fourier Transform Infrared Spectroscopy (FTIR). Differential Scanning Calorimetry (DSC) and Thermal Gravimetry Analysis (TGA) were used to examine the thermal behavior of synthesized conducting homopolymers and copolymers. The morphologies of the films were investigated by Scanning Electron Microscope (SEM). Two-probe technique was used to measure the conductivities of the samples. Moreover, investigations of electrochromic and spectroelectrochemical properties of poly(TAPE) and TAPE/BiTh copolymer were done. Keywords: Conducting copolymers, electrochromic properties

This research investigates the use of conducting polymer coatings on platinum (Pt) electrodes for use in neuroprostheses. Conducting polymers aim to provide an environment conducive to neurite outgrowth and attachment at the electrode sites, producing intimate contact between neural cells and stimulating electrodes. Conducting polymers were electropolymerised onto model Pt electrodes. Conventional polymers polypyrrole (PPy) and poly-3,4-ethylenedioxythiphene (PEDOT) doped with polystyrenesulfonate (PSS) and para-toluenesulfonate (pTS)were investigated. Improvement of material properties was assessed through the layering of polymers with multi-walled carbon nanotubes (MWNTs). The ability to incorporate cell attachment bioactivity into polymers was examined through the doping of PEDOT with anionic laminin peptides DCDPGYIGSR and DEDEDYFQRYLI. Finally, nerve growth factor (NGF), was entrapped in PEDOT during polymerisation and tested for neurite outgrowth bioactivity against the PC12 cell line. Each polymer modification was assessed for electrical performance over multiple reduction-oxidation cycles, conductivity and impedance spectroscopy, mechanical adherence and hardness, and biological response. Scanning electron microscopy was used to visualise film topography and x-ray photon spectroscopy was employed to examine chemical constitution of the polymers. For application of electrode coatings to neural prostheses, optimal bioactive conducting polymer PEDOT/pTS/NGF was deposited on electrode arrays intended for implantation. PC12s were used to assess the bioactivity of NGF functionalised PEDOT when electrode size was micronised. Flexibility of the design was tested by tailoring PEDOT bioactivity for the cloned retinal ganglion cell, RGC-5, differentiated via staurasporine. It was established that PEDOT films had superior electrical and cell growth characteristics, but only PPy was able to benefit from incorporation of MWNTs. Bioactive polymers were produced through inclusion of both laminin peptides and NGF, but the optimum film constitution was found to be PEDOT doped with pTS with NGF entrapped during electrodeposition. Application of this polymer to an implant device was confirmed through positive neurite outgrowth on vision prosthesis electrode arrays. The design was shown to be flexible when tailored for RGC-5s, with differentiation occurring on both PEDOT/pTS and PEDOT/DEDEDYFQRYLI. Conducting polymers demonstrate the potential to improve electrode-cell interactions. Future work will focus on the effect of electrical stimulation and design of bioactive polymers with improved cell attachment properties.

Thesis (D.M.A.)--University of California, Los Angeles, 2007. / Vita. Includes discography (leaf 87) and bibliographical references (leaves 83-86).

Thesis (M.S.)--Rochester Institute of Technology, 2009. / Typescript. Includes bibliographical references (leaves 103-105).

Treatise (D.M.A.)--University of Texas at Austin, 2004. / Supervisors: Marianne Wheeldon and Kevin Noe. Vita. Also available from UMI.

Thesis (Ph.D.)--University of Wollongong, 2004. / Typescript. Includes bibliographical references: leaf 242-269.

Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.

Thesis (D. Mus. Ed.)--Indiana University, 1963. / Includes bibliographical references.