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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.
1

Synthesis and applications of nitroxide radical polymer brushes grafted onto silica nanoparticles and Fe3O4@SiO2 core-shell nanoparticles

Yang, Jian-jhe 24 August 2012 (has links)
Nitroxide radical groups grafted on silica have been synthesized. The catalytic oxidation of alcohols to aldehydes and ketones using the nitroxide radical groups as a catalyst was also investigated. The results of scanning electron microscopy, infrared spectroscopy, and X-ray photoelectron spectroscopy confirmed that the nitroxide radical groups are successfully grafted onto silica. The yield of the catalytic oxidation using the catalysts is higher than 99%. The catalysts are easily recovered. Furthermore, the reused catalysts still keep high performance in the catalytic oxidation.
2

Synthesis Of Macromolecular Catalyst Systems And Applications

Oguzkaya, Funda 01 September 2011 (has links) (PDF)
SYNTHESIS OF MACROMOLECULAR CATALYST SYSTEMS AND APPLICATIONS Oguzkaya, Funda PhD., Department of Chemistry Supervisor: Prof. Dr. Cihangir Tanyeli September 2011, 144 pages The thesis mainly proposed to design macromolecular catalyst systems. Such catalysts should follow the way of &quot / Green Chemistry&quot / with including no metallic ions and have also the ability of reusability. Hence, nitroxide chemistry was chosen as the key point. Catalysts were synthesized with surely including TEMPO as the functional part as the most preferable nitroxide derivative. As a skeleton, norbornene was chosen firstly. Following obtaining 3-(methoxycarbonyl) bicyclo[2.2.1]hept-5-ene-2-carboxylic acid (49), 4-aminoTEMPO was attempted to be inserted in the structure. In this case, 4-aminoTEMPO was preferred as a TEMPO derivative so as to include reactive amine functional group. As a result, two different monomers were obtained. Then, Ring Opening Metathesis Polymerization via first generation Grubbs catalyst was adjusted to reach target macromolecules. Furthermore, as a second type skeleton for the catalyst, Thiophene-Pyrrole-Thiophene (SNS) structure was chosen, since these well-known structures have the ability to polymerize easily. Anelli Oxidation protocol including corresponding catalysts in combination with NaOCl+NaHCO3 (pH 9.1) and KBr resulting in remarkable high activity with low catalyst concentrations typically 1 mol % was chosen for the oxidation of alcohols so as to reach to target aldehydes and ketones. Investigation of other applicable areas via collaborative studies was thought to open the way of electrochromic and biosensor studies as the different points of view. Electropolymerization was performed in a three-electrode cell consisting of an Indium Tin Oxide coated glass slide (ITO) as the working electrode, platinum wire as the counter electrode and Ag wire as the pseudo reference electrode. As the biosensor part, glucose oxidase (GOx) was used as the model enzyme for glucose oxidation in the presence of molecular oxygen. Poly-SNS-based carboxylic acid served as an excellent immobilization matrix for glucose sensing. Key words: TEMPO, Anelli Oxidation

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