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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.

Studies of the dilute solution conformational dynamics of homopolymer stars and combs via oscillatory flow birefringence

Dibbs, Mitchell Gene. January 1983 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1983. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 296-301).

Electrostatic and hydrodynamic interactions of charged macromolecular systems

Piatt, David Michael. January 1981 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1981. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 245-255).

Functional dendrimers: synthesis and applications.

January 1995 (has links)
by Chi Ching Mak. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 122-130). / Contents --- p.i / Acknowledgments --- p.iii / Abstract --- p.iv / Abbreviations --- p.v / List of publications originated from this thesis --- p.vi / Chapter I --- Introduction to Dendrimer Chemistry / Chapter I-1 --- Background --- p.1 / Chapter I-2 --- Comparison of Dendrimer and Linear Polymer --- p.6 / Chapter I-3 --- Synthesis --- p.8 / Chapter I-3-1 --- Divergent-growth Approach --- p.8 / Chapter I-3-2 --- Convergent-growth Approach --- p.10 / Chapter I-3-3 --- Accelerated Approach --- p.11 / Chapter II --- Functional Dendrimers --- p.14 / Chapter III --- Optically Active Dendrimers / Chapter III-1 --- Background --- p.18 / Chapter III-2 --- Architecture of Tartaric Acid-based Optically Active Dendrimers --- p.23 / Chapter III-3 --- Results and Discussion --- p.24 / Chapter III-3-1 --- Syntheses and Structure Elucidations of all (L)-Tartaric Acid-based Dendrimers 41 and 42 --- p.24 / Chapter III-3-2 --- Syntheses and Structure Elucidations of Optically Active Layer-block Dendrimers 43 and 44 --- p.29 / Chapter III-3-3 --- Structure-Optical Rotation Relationships --- p.33 / Chapter III-3-4 --- "Syntheses and Characterization of Higher Generation, Optically Active Dendritic Fragments" --- p.37 / Chapter III-3-5 --- Conclusions --- p.43 / Chapter IV --- Catalytic Dendrimers / Chapter IV-1 --- Background --- p.44 / Chapter IV-2 --- Syntheses and Characterization of Dendritic Bis(oxazoline) Copper(II) Catalyst --- p.47 / Chapter IV-2-1 --- Architecture --- p.47 / Chapter IV-2-2 --- Syntheses of the Bis(oxazoline) Core Precursors --- p.49 / Chapter IV-2-3 --- Syntheses of the Achiral Dendritic Sectors --- p.51 / Chapter IV-2-4 --- Syntheses of Dendritic Ligands --- p.52 / Chapter IV-3 --- Kinetics and Selectivity of Dendritic Bis(oxazoline)-Copper(II) Complex Catalyzed Diels-Alder Reaction --- p.55 / Chapter IV-3-1 --- Introduction --- p.55 / Chapter IV-3-2 --- Reaction Mechanism and Reactivity Kinetics --- p.56 / Chapter IV-3-3 --- Substrate Selectivity --- p.63 / Chapter IV-4 --- Syntheses and Properties of Optically Active Dendritic Bis(oxazoline) Ligands and Their Copper(II) Complexes Catalysts --- p.65 / Chapter IV-4-1 --- Background --- p.65 / Chapter IV-4-2 --- Syntheses and Characterization of Chiral Dendritic Bis(oxazoline) Ligands 109-112 --- p.67 / Chapter IV-4-3 --- Chiroptical Properties --- p.72 / Chapter IV-4-4 --- Enantioselectivity of the Metal-catalyzed Diels-Alder Reaction --- p.73 / Chapter IV-4-5 --- Conclusions --- p.74 / Chapter V --- Summary --- p.75 / Chapter VI --- Experimental --- p.77 / References --- p.122 / Spectra --- p.131

Investigations of Lennard-Jones fluids and their binary mixtures by simulation and theory

Holtz, Barbara January 1996 (has links)
No description available.

Determination of end - absorbed polymer density profiles by Neutron Reflection Spectroscopy

Field, James Barry January 1992 (has links)
No description available.

Overcoming challenges in macromolecular crystallography

Tourigny, David Scott January 2014 (has links)
No description available.

Synthesis, characterisation and properties of novel dendrimers

Stoddart, Alison January 2002 (has links)
A new family of aliphatic, polyurethane dendritic macromolecules has been designed, synthesised and characterised. The convergent route to dendrimers and the reactions of the selective coupling agent, carbonyl diimidazole (GDI) were employed. The method was successful in the preparation of first, second and third generation dendrimers and dendrons of the first to fourth generations. The structure of the termini of these branched macromolecules was varied to consist of r-butyl, benzhydryl, cyclohexyl or 4-heptyl groups. The dendrons were also coupled to a trifunctional aromatic core unit to create another series of dendrimers with an innermost layer of ester functions. The compounds prepared were soluble in most common organic solvents and insoluble in water. The physical state of the materials ranged from sticky oils to hard, amorphous solids depending on the nature of the end groups and the molecular weight of the macromolecules. The synthesis of the second generation dendrimer with (-butyl end groups was adapted to make a series of six codendrimers with differing arrangements of concentric layers of urethane and carbonate functions as well as the polycarbonate analogue. These second-generation dendrimers varied in their physical state from oils of low viscosity to hard amorphous solids depending on the proportion of carbonate and urethane functions in the molecule. The hydrogen bonding interactions in solution of some of the dendritic compounds were investigated by (^1)H NMR and infrared spectroscopy. From the analysis it was concluded that the hydrogen bonding was intramolecular rather than intermolecular in nature and that the degree of hydrogen bonding was dependent on the generation and the terminal groups of the structures. In addition, the degree of hydrogen bonding of the urethane functions was observed to be dependent on the location of the urethane layers in the second generation poly(urethane-carbonate) codendrimers. The thermal properties of the dendrimers were investigated and the materials observed to have a single glass transition. The glass transition temperatures of the dendritic families with different termini were found to be dependent on the composition of the end group and the molecular weight of the molecule. The glass transition temperatures of the codendrimers were dependent on the proportion of urethane and carbonate links in the structure and also the relative location of the layers. In a preliminary study, it was shown that blends of two different dendrimers were characterised by only one glass transition.

Octopus and dendrimer molecules with silsesquioxane cores

Gentle, Theresa Eileen January 1995 (has links)
The interest in materials with designed physical properties and controlled molecular formula is increasing. Octopus molecules, or materials with pendent groups from a core, and dendrimer molecules, or materials with a defined pattern of branching from a core are means of obtaining molecules of designed architecture. The work presented here involves the synthesis and characterization of octopus and dendrimer molecules of defined shape with molecular weights well into the thousands. These designed molecular materials have been synthesized by placing pendant groups symmetrically about a silsesquioxane [(SiO<sub>3/2</sub>)<sub>8</sub>] core. A facile, one-step route to hydrocarbon and siloxane functional octopus molecules via H2PtC16 catalyzed hydrosilylation of 1-alkenes and vinyl-functional siloxanes by T<sub>8</sub> hydrogen silsesquioxane, (HSiO<sub>3/2</sub>)<sub>8</sub>, has been demonstrated. The chemistry of addition was studied, and it was found that while the addition of the I-alkenes to T<sub>8</sub> was, regioprecise with only a-addition being observed, both a- and ß-addition occurred with vinyl siloxanes. In addition, H/vinyl exchange on silicon was observed to occur with addition of vinyl-siloxane to T<sub>8</sub>. The effect of the hydrosilylation catalyst, homogeneous and heterogeneous, on the regioselectivity of addition and on the extent of exchange on silicon has been evaluated via GPC and <sup>13</sup>C and <sup>29</sup>Si NMR. Investigations into the feasibility of placing a number of other moieties on the silsesquioxane core to show the almost limitless types of functional octopus molecules that can be made and to expand into dendritic molecules were also accomplished. For example polyether functional and mixed polyether/siloxane functional octopus molecules were synthesized and found to have interesting surface activity. The synthesis of an acrylate functional octopus molecule was accomplished and the product used to produce an ultra-violet curable coating. Finally, routes other than hydrosilylation to produce octopus and dendrimer molecules with silsesquioxane cores, for instance, the reaction of ROH with SiH of (SiO<sub>3/2</sub>)<sub>8</sub>, were developed and used to increase the types of functional octopus possible and to produce dendrimer molecules with silsesquioxane cores. The synthesis, characterization, and possible applications of silsesquioxane-based octopus and dendrimer molecules will be discussed.

Single macromolecules under tension and in confinement

Otto, Oliver January 2012 (has links)
No description available.

Infinite dilution viscoelastic properties of two partially flexible macromolecules

Rosser, Robin Wallace. January 1977 (has links)
Thesis--Wisconsin. / Vita. Includes bibliographical references (leaves 136-141).

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