Spelling suggestions: "subject:"copolymer""
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Design, synthesis, and characterization of functional block copolymers containing fluorinated or hydrophilic segments by ATRPBucholz, Tracy Laine, 1981- 04 September 2012 (has links)
Well-defined functional block copolymers containing either a fluorinated or a hydrophilic segment can be synthesized via a controlled free-radical technique, known as atom transfer radical polymerization (ATRP). Their self assembly characteristics in the solid state and in solution were examined in this work with the aim of developing ultralow dielectric constant materials and templates for conductive polymer synthesis, respectively. We demonstrated the controlled synthesis via ATRP of block copolymers containing poly(pentafluorostyrene) (PPFS) and a degradable polymer, such as poly(methyl methacrylate) (PMMA), poly([epsilon]-caprolactone) (PCL), or poly(D,L-lactide) (PLA). These block copolymers microphase separate in the solid state to form periodic nanostructures, such as alternating lamellae, a bicontinuous gyroid on a cubic lattice, cylinders on a hexagonal lattice, or spheres on a body-centered-cubic lattice, depending on the volume fraction of each block and the interblock segregation strength. Additionally, we quantified the interblock segregation strength of PPFS/PMMA, demonstrating that this block copolymer is only approximately twice as segregated as its nonfluorinated counterpart poly(styrene-[beta]-methyl methacrylate) due to the symmetric placement of the polar C-F bonds on the benzene ring in PPFS. We also showed that the self-assembly characteristics of PPFS-containing block copolymers can be used to create nanoporous fluorinated films with ultra-low dielectric constants in the range of 1.7 - 1.9. The dielectric constants are tunable through manipulation of the volume fraction of the degradable block in the parent block copolymers. We also demonstrated the controlled synthesis via ATRP of block copolymers containing poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAAMPSA) with either poly(oligo(ethylene glycol) methyl ether methacrylate) (PEGMA) or poly(methyl acrylate) (PMA). We showed that PEGMA/PAAMPSA formed well-ordered nanostructures in the solid state when cast from strong hydrogen bond accepting solvents, such as DMSO and DMF. PEGMA/PAAMPSA can also be used as the acid dopant in the synthesis of conductive polyaniline (PANI). Additionally, we studied the micelle formation of PMA/PAAMPSA and subsequently used these micelles as templates to create spherical conductive PANI nanoparticles. The size and size distribution of these PANI nanoparticles were dictated by the corresponding characteristics of the micellar template. / text
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Coiled-coils as assembly-directing domains in self-assembling structuresSahin, Erinc. January 2008 (has links)
Thesis (Ph.D.)--University of Delaware, 2008. / Principal faculty advisor: Kristi L. Kiick, Dept. of Materials Science & Engineering. Includes bibliographical references.
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Highly-ordered onion micelles made from amphiphilic highly-branched copolymersCanning, S.L., Ferner, J.M.F., Mangham, N.M., Wear, T.J., Reynolds, S.W., Morgan, J., Fairclough, J.P.A., King, S.M., Swift, Thomas, Geoghegan, M., Rimmer, Stephen 11 December 2018 (has links)
Yes / Uniform onion micelles formed from up to ten nano-structured polymer layers were produced by the
aqueous self-assembly of highly-branched copolymers. Highly-branched poly(alkyl methacrylate)s were
chain extended with poly(acrylic acid) in a two-step reversible addition–fragmentation chain transfer-self-condensing
vinyl polymerization (RAFT-SCVP) in solution. The resulting polymers were dispersed into
water from oxolane (THF) using a self-organized precipitation-like method and the self-assembled particles
were studied by phase-analysis light scattering, small-angle neutron scattering, and electron
microscopy techniques. The relative hydrophobicity of the blocks was varied by changing the alkyl methacrylate
(methyl, butyl, or lauryl) and this was found to affect the morphology of the particles. Only the
poly(butyl methacrylate)-containing macromolecule formed an onion micelle structure. The formation of
this morphology was observed to depend on: the evaporation of the good solvent (THF) during the self assembly
process causing kinetic trapping of structures; the pH of the aqueous phase; and also on the
ratio of hydrophobic to hydrophilic segments within the copolymer. The lamellar structure could be
removed by annealing the dispersion above the glass transition temperature of the poly(butyl methacrylate).
To exemplify how these onion micelles can be used to encapsulate and release an active compound,
a dye, rhodamine B (Rh B), was encapsulated and released. The release behaviour was dependent
on the morphology of the particles. Particles formed containing the poly(methyl methacrylate) or poly
(lauryl methacrylate) core did not form onions and although these materials absorbed Rh B, it was continuously
released at room temperature. On the other hand, the lamellar structure formed from branchpoly(
butyl methacrylate)-[poly(butyl methacrylate)-block-poly(acrylic acid)] allowed for encapsulation of
approximately 45% of the dye, without release, until heating disrupted the lamellar structure. / EPSRC and Domino UK Ltd for a Nanotechnology KTN CASE studentship to support SLC, Experiments at the ISIS Pulsed Neutron and Muon Source were supported by a beam time allocation from the Science and Technology Facilities Council (experiment numbers RB1220108 and RB1320167).
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A study of the adsorption of a randon copolymer£ at the solid-liquid interfaceFinch, N. A. January 1988 (has links)
No description available.
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Degradation and stabilisation studies of S-EB-S block copolymerMourelatou, Despina January 2003 (has links)
No description available.
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Synthesis and properties of hydrophilic copolymersDavis, T. P. January 1987 (has links)
No description available.
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The activation of wood fibre for thermoplastic couplingQuinney, Richard January 1996 (has links)
No description available.
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Surface-tunable photoluminescence and nonlithographic patterning of block copolymer-stabilized cadmium sulfide quantum dotsWang, Chih-Wei (Chih-Wei Jo). 10 April 2008 (has links)
No description available.
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The formation of mesoglobular phase of heteropolymers in dilute solution.January 2002 (has links)
Siu Man Hin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references. / Abstracts in English and Chinese. / Abstract --- p.i / Abstract in Chinese --- p.iv / Acknowledgement --- p.vi / Content --- p.vii / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Protein folding - Coil-to-globule transition --- p.1 / Chapter 1.2 --- Quaternary structure of proteins - Aggregation --- p.5 / Chapter 1.3 --- The effect of fast and slow heating rate to the aggregation of copolymers --- p.11 / Chapter 1.4 --- Main goal in thesis --- p.14 / Chapter 1.5 --- References --- p.18 / Chapter Chapter 2 --- Fundamentals of light scattering and instrumentation / Chapter 2.1 --- Static laser light scattering --- p.21 / Chapter 2.2 --- Dynamic light scattering --- p.22 / Chapter 2.3 --- Correlation function profile analysis --- p.24 / Chapter 2.4 --- Molar mass distribution and conformation of polymers --- p.25 / Chapter 2.5 --- Instrumentation / Chapter 2.5.1 --- Light source --- p.27 / Chapter 2.5.2 --- Cell design --- p.28 / Chapter 2.5.3 --- Detector --- p.28 / Chapter 2.5.4 --- Differential refractometer --- p.29 / References --- p.30 / Chapter Chapter 3 --- The effect of comonomer distribution on the coil-to-globule transition of a single AB copolymer chain in dilute solution / Chapter 3.1 --- Introduction --- p.32 / Chapter 3.2 --- Experimental / Chapter 3.2.1 --- Sample preparation and characterization --- p.35 / Chapter 3.2.2 --- Differential Scanning Calorimeter --- p.37 / Chapter 3.3 --- Results and discussion --- p.38 / Chapter 3.4 --- References --- p.49 / Chapter Chapter 4 --- Formation of mesoglobular phase of amphiphilic copolymer chains in dilute solution: 1. Effect of comonomer distribution / Chapter 4.1 --- Introduction --- p.50 / Chapter 4.2 --- Sample preparation and characterization --- p.53 / Chapter 4.3 --- Results and discussion --- p.54 / Chapter 4.4 --- References --- p.65 / Chapter Chapter 5 --- Formation of mesoglobular phase of amphiphilic copolymer chains in dilute solution: 2. Effect of comonomer distribution / Chapter 5.1 --- Introduction --- p.66 / Chapter 5.2 --- Sample preparation and characterization --- p.69 / Chapter 5.3 --- Results and discussion --- p.71 / Chapter 4.4 --- References --- p.80
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Nanopore-extrusion induced sphere-to-cylinder transition of block copolymer micelles. / CUHK electronic theses & dissertations collectionJanuary 2013 (has links)
Chen, Qianjin. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
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