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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
401

Mass spectrometric investigations into free radical polymerisation reaction mechanisms

Hart-Smith, Gene On, Chemistry, Faculty of Science, UNSW January 2009 (has links)
Contemporary mass spectrometry (MS) instrumentation featuring electrospray ionisation (ESI) or matrix-assisted laser desorption/ionisation (MALDI) ion sources were used to characterise the polymer distributions generated in various free radical polymerisations, allowing insights to be gained into the reaction mechanisms operating in these systems. In studying atom transfer radical polymerisation (ATRP) mediated star polymerisations of methyl acrylate (MA), ESI was found to be more effective in obtaining a comprehensive list of the distinct products present in the samples under investigation when compared to the employed MALDI technique. Furthermore, these studies showed that terminal Br losses observed at relatively high monomer to polymer conversions could be accounted for via mechanisms involving the acetone derived radicals (CH3)2??OH, ??H3 and ??H2COCH3. Through the use of ESI, it was found that for bulk polymerisations of MA and aqueous media polymerisations of N-isopropylacrylamide (NIPAAm) initiated using 60Co ??-irradiation and mediated via reversible addition-fragmentation chain transfer (RAFT), hydrogen radicals formed via the radiolysis of RAFT agent and/or monomer, and in the case of the NIPAAm system, water, are capable of initiating the polymerisations. In the NIPAAm polymerisations under scrutiny, it was also observed that hydroxyl radicals generated via the radiolysis of water may contribute towards the initiation process, and that propagating chains can potentially become terminated via trithiocarbonate cleavage reactions. By using ESI instruments to characterise oligomer samples produced via the free radical polymerisations of vinyl phosphonates, it was observed that chain propagations are initiated via activated monomer radicals, which likely form as a result of transfer reactions involving initiator fragments and vinyl phosphonate monomer units. Transfer to monomer reactions were suggested to limit chain growth in these systems, and evidence was also found for scission reactions involving alkoxy moieties which are formed via intramolecular methine carbon abstraction reactions. Characterisation of the polymer distributions generated in R-group approach RAFT MA star polymerisations using an ESI instrument allowed formation processes operating in acrylate star living/controlled radical polymerisations (CRPs) to be ascertained. Initiator fragment derived linear chains, ideal stars, star-star couples, and terminated star products formed as a result of disproportionation and combination reactions were detected. Evidence for mid-chain radical (MCR) derived reaction pathways was also observed; specifically, for termination reactions involving intermolecularly formed MCRs on both star arms and linear chains, and for re-propagation of intermolecularly formed MCRs on star arms.
402

Quantitative analysis of genetic variations using molecular affinity and MALDI-TOF mass spectrometry

Kim, Aana Moon. January 2007 (has links)
Thesis (M.S.)--Rutgers University, 2007. / "Graduate Program in Biomedical Engineering." Includes bibliographical references (p. 23-24).
403

Liquid chromatography-mass spectrometry as a tool for drug metabolite identification in biological fluids : with application to Ketobemidone /

Sundström, Ingela, January 2007 (has links)
Diss. (sammanfattning) Uppsala : Uppsala universitet, 2007. / Härtill 4 uppsatser.
404

Structural analysis of ginsenosides and sugars : an electrospray and tandem mass spectrometry study /

Ackloo, Suzanne. January 2001 (has links)
Thesis (Ph.D.) -- McMaster University, 2001. / Includes bibliographical references. Also available via World Wide Web.
405

A mass spectrometric study of low energy rearrangement reactions in oxygen-containing ions.

Suh, Dennis Dong-Kyun. Terlouw, J.K. Unknown Date (has links)
Thesis (Ph.D.)--McMaster University (Canada), 1996. / Source: Dissertation Abstracts International, Volume: 57-10, Section: B, page: 6228. Adviser: J. K. Terlouw.
406

Measurements of in-situ production of (14)C in SiO(2): Production rates and cross-sections.

Roman, Herminia. Kuehner, J.A. Southon, J.R. Unknown Date (has links)
Thesis (Ph.D.)--McMaster University (Canada), 1989. / Source: Dissertation Abstracts International, Volume: 62-13, Section: A, page: 0000.
407

Methods for mass spectrometric proteome analysis /

Ossipova, Elena, January 2008 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2008. / Härtill 4 uppsatser.
408

Characterization of microorganisms of interest to homeland security and public health utilizing liquid chromatography/mass spectrometry

Everley, Robert Anthony, January 1900 (has links)
Thesis (Ph.D.)--Virginia Commonwealth University, 2008. / Title from title-page of electronic thesis. Prepared for: Dept. of Chemisty. Bibliography: leaves 134-141.
409

Negative ion chemistry of boron and carbon compounds /

Currie, Graeme. January 1988 (has links) (PDF)
Thesis (Ph. D.)--University of Adelaide, 1989. / Includes bibliographical references (leaves 134-148).
410

Protein characterization by capillary isoelectric focusing electrophoresis, reversed phase liquid chromatography and mass spectrometry

Zhou, Feng. January 2008 (has links)
Thesis (Ph. D.)--University of Delaware, 2007. / Principal faculty advisor: Murray V. Johnston, III, Dept. of Chemistry & Biochemistry. Includes bibliographical references.

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