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dc.contributor.authorJones, Jason Williamen_US
dc.date.accessioned2014-03-14T20:33:52Z
dc.date.available2014-03-14T20:33:52Z
dc.date.issued2001-02-16en_US
dc.identifier.otheretd-04192001-153328en_US
dc.identifier.urihttp://hdl.handle.net/10919/31766
dc.description.abstractDue in large part to the growth and development of reliable surface characterization techniques, as well as to advances in the physical and chemical techniques used to modify surfaces, the technology of surface modification has seen rapid expansion over the past two decades. A major thrust of this research is the growth of controlled/"living" polymeric brushes from the surface of various substrates, an advance that promises to be a facile and reproducible way of altering surface properties. A unique initiator bearing ATRP (atom transfer radical polymerization), cleavage, and condensation functionalities was prepared and attached to the hydrolyzed surface of silica gel. Preliminary results indicate that control of reversibly terminated grafts of varying degrees of polymerization with polydispersity indices approaching 1.5 can be readily achieved-significant findings in the quest to design desired surface characteristics. Important physical characteristics may also be altered by way of varying molecular topologies. In the second major research thrust, the use of self-assembly to construct such topologies in the form of pseudorotaxanes fashioned from diverse macrocycles with multifarious guest ions is discussed. While the underlying goal was to investigate and understand the mode of complexation based on such environmental factors as substituent affects and neighboring group influences, new insight was gained on the synthetic manipulation of cooperative events-events that freely occur in nature. The complexation behavior of several functionalized bis-(meta-phenylene)-32-crown-10 macrocycles with various paraquat guest moieties was. As expected, studies indicated that electron-donating substituents on the crown ether drive association, a likely result of increased p -p interactions among host and guest species. The association between a bicyclic macrocycle and dimethyl paraquat was also investigated. Not surprisingly, binding of paraquat by the bicyclic was much stronger than the binding found in analogous macrocycles. Lastly, the endgroup functionalization of poly(propyleneimine) dendrimers with two crown ether macrocycles was performed and the complexation with host-specific guests studied. Curiously, two extreme binding regimes were found: the larger 32-membered crown ether assembly displayed anti-cooperative behavior upon complexation with paraquat, while the smaller 24-membered macrocyclic system exhibited cooperative effects with 2o ammonium ions. These cooperative results are among the very first described for non-biological systems and hint at their potential use in developing highly efficient, synthetically designed supramolecular systems.en_US
dc.publisherVirginia Techen_US
dc.relation.haspart5_Table_of_Contents.pdfen_US
dc.relation.haspart4_Acknowledgements.pdfen_US
dc.relation.haspart10_Chapter_2.pdfen_US
dc.relation.haspart2_Abstract.pdfen_US
dc.relation.haspart1_Title.pdfen_US
dc.relation.haspart6_Table_of_Figures.pdfen_US
dc.relation.haspart9_Chapter_1.pdfen_US
dc.relation.haspart3_Preface.pdfen_US
dc.relation.haspart7_Table_of_Schemes.pdfen_US
dc.relation.haspart8_Table_of_Tables.pdfen_US
dc.relation.haspart11_Chapter_3.pdfen_US
dc.relation.haspart13_Vita.pdfen_US
dc.relation.haspart12_Appendix_I.pdfen_US
dc.rightsI hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Virginia Tech or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.en_US
dc.subjectAllosteric Interactionsen_US
dc.subjectCryptandsen_US
dc.subjectSelf-Assemblyen_US
dc.subjectPseudorotaxanesen_US
dc.subjectSurface Modificationen_US
dc.subjectControlled Radical Polymerizationen_US
dc.subjectAssociation Constantsen_US
dc.subjectCrown Ethersen_US
dc.subjectDendrimersen_US
dc.titleEnhanced Architectural and Structural Regulation Using Controlled Free Radical Polymerization Techniques; Supramolecular Assemblies: Pseudorotaxanes and Polypseudorotaxanesen_US
dc.typeThesisen_US
dc.contributor.departmentChemistryen_US
dc.description.degreeMaster of Scienceen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineChemistryen_US
dc.contributor.committeechairGibson, Harry W.en_US
dc.contributor.committeememberLong, Timothy E.en_US
dc.contributor.committeememberMarand, Hervé L.en_US
dc.contributor.committeememberMcGrath, James E.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-04192001-153328/en_US
dc.date.sdate2001-04-19en_US
dc.date.rdate2002-04-24
dc.date.adate2001-04-24en_US


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