Block copolymers containing pendant pyrene, terpyridine and poly(3- hexylthiophene) moieties with different block ratios and chain lengths were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization. The block copolymers obtained had narrow molecular weight distribution. The applications of these polymers for non-covalent functionalization of carbon nanotubes and in photovoltaic devices were studied. The molecular weight distribution and block sizes of the block copolymers could be controlled quite well. The polydispersities measured were below 1.25. The block copolymers could be functionalized on the surface of CNTs. The functionalized CNTs had an improved dispersing ability and a maximum dispersing ability of 0.30 mgmL-1 in DMF was achieved. The photosensitizing properties of an individual functionalized CNT were studied by conductive atomic force microscopy. In the presence of the photosensitizing unit, the photocurrent was measured to be 6.4 nAμW-1 at 580 nm. This suggests the role of metal complexes in the photosensitizing process in the block copolymer. Poly(3-hexylthiophene)-block-pendant pyrene copolymers were synthesized by Grignard metathesis and RAFT polymerization. Different loadings of the block copolymers functionalized CNT were employed as the electron accepting materials in bulk heterojunction photovoltaic devices. A maximum power conversion efficiency of 0.77 × 10-3 % was achieved for the poly(3- hexylthiophene): 0.5% polymer functionalized CNT devices. The poor efficiency was attributed to the low CNT loadings that limited the electron transport in the devices. The poly(3-hexylthiophene)-block-pendant pyrene copolymer were employed as compatibilizer for poly(3-hexylthiophene): [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) bulk heterojunction photovoltaic devices. With the addition of 20 % of the block copolymer, a maximum power conversion efficiency of 1.62 % could be achieved. The long term stability of the encapsulated photovoltaic devices was studied. There was more than 30 % reduction in the degradation of performance after 30 days when the block copolymer was added as compatibilizer. These results suggested the role of the block copolymer compatibilizers in improving both the photovoltaic performances and stability of the devices. Differential scanning calorimetry results suggested that the improved photovoltaic performances may be attributed to the enhanced compatibility between poly(3- hexylthiophene) and PCBM. / published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / toc / Physics / Master / Master of Philosophy

No description available.

No description available.

Poly(methyl methacrylate) (PMMA) homopolymers synthesised using 'classical' anionic methods and subsequently studied by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF-MS) are discussed. Specifically, the attempts at different end-group functionalisation reactions, their varying degrees of success, and the characterisation of these functionalized polymers via MALDI are reported. Extra peaks were observed in the spectra of samples containing a tertiary amine end-group. A mechanism for the in situ elimination of H(_2)(g) involving these end-groups, which would fit the observations, is proposed. Two alternative, 'non-classical' routes to the desired materials were investigated, as difficulties in successfully performing capping reactions to give end functionalised PMMA were noted. The first method was a variation of standard anionic polymerisation that involved the use of lithium silanolates, which could be performed at a higher temperature than normal. The second was a controlled free-radical technique known as Reversible Addition-Fragmentation Chain Transfer (RAFT). A lack of control of the polymerisation to the desired degree was observed with the former method. A well-defined RAFT sample was observed to undergo in situ eliminadon also, for which a mechanism involving the dithioester end-group is proposed, and which is supported by MALDI-collision induced dissociation (CID) evidence. The synthesis of block copolymers of various compositions of MMA with r-butyl methacrylate (t-BMA) and hexyl methacrylate (HMA), along with their homopolymers, and their subsequent characterisation is reported. PHMA was analysed easily, in contrast to Pt-BMA. Only copolymers with a high PMMA content were analysed successfully and this has been rationalised in terms of the factors that affect cationisation. The characterisation of equimolar blends of various end-functionalised PMMA samples is reported also. Samples that favour the binding of a metal ion over protonation appear to have a higher ion yield. Once more, these observations are rationalised in terms of the factors that affect cationisation.

No description available.

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

Thesis (Ph.D.) -- McMaster University, 1998. / Includes bibliographical references. Also available via World Wide Web.

Thesis (Ph.D.)--Case Western Reserve University, 2009 / Abstract Department of Macromolecular Science and Engineering Title from PDF (viewed on 16 April 2009) Available online via the OhioLINK ETD Center

Thesis (Ph. D.)--University of Chicago, Dept. of Physics, December 1997. / Includes bibliographical references. Also available on the Internet.