Research in the self-assembly properties of block copolymers in solution is an established field. Micellar block copolymer aggregates have transcended the fascination of those who study these materials into a broad range of advanced applications. The general goals in materials research revolve around gaining access to new structures, or simplifying pathways of producing known structures, and understanding their behavior in various environments. The morphological dynamics of block copolymer micelles, in response to external changes, have been exploited for a variety of purposes. The present thesis describes crystallinity-driven dynamic behavior that is intrinsic to block copolymer micelles bearing a polycaprolactone core. The first part is concerned with the morphological dynamics of spherical poly(ethylene oxide)-block-polycaprolactone micelles and their relevance to potential pharmaceutical applications. Following nucleation within the micelle core, which transforms micelles into metastable structures, spheres change into elongated rods or ribbons in a reproducible and predictable manner, which is also reversible at temperatures above the melting point. In the next part, homopolymer additives are employed to enhance this crystallinity-induced self-assembly behavior, yielding large lamellar aggregates akin to single crystals of the block copolymer. The uptake of homopolymer chains during micellization has no effect on morphology at first; however, following core crystallization, spherical micelles associate to form rods, which then form lamellae by alignment and coalescence. The self-assembly of supramolecular rods in two dimensions, which was given the name "raft" formation, to yield a discrete lamellar object has not been encountered before. The morphogenic effects of homopolymers are investigated in greater detail in the following part of this thesis, where the phenomenon is attributed to fractional crystallization within the micelle core: surface-exposed homopolymers bridge micellar species together in either one or two dimensions. This materials design principle is applied successfully to polyelectrolyte-stabilized micelles bearing chains of poly(acrylic acid) in the corona. In the final part of this thesis, chain-end modified copolymers are prepared and their self-assembly properties investigated. Spherical micelle formation is unaffected by the functional groups that are introduced, and these spheres also resist morphological change. Surprisingly, some derivatives show signs of phase separation within the micelle core, forming electron-dense nanodomains. Overall, this thesis illustrates how morphology in core-crystalline micelle systems is a dynamic parameter, and that control over these dynamics offers the opportunity to design novel and functional materials. / Les copolymères à blocs contenant des chaines macromoléculaires chimiquement incompatibles peuvent, dans les conditions appropriées, former des agrégats micellaires. Les principaux objectifs de la recherche sur ces matériaux auto-assemblés sont la production de nouvelles structures et le développement de méthodes synthétiques; dans un contexte technologique, il est essentiel de pouvoir prédire les propriétés des matériaux en fonction de leur environnement. Cette thèse porte sur la morphologie des micelles de copolymères à blocs contenant un segment de polycaprolactone et, en particulier, sur les paramètres qui affectent l'évolution de la cristallisation de ce segment. L'aspect des micelles de poly(oxyethylène)-bloc-polycaprolactone est présenté dans la première partie de cette thèse, ces micelles biodégradables ayant déjà démontré un grand potentiel dans le domaine pharmaceutique. Telles que produites, ces micelles ont une morphologie sphérique; par contre, suite à la cristallisation dans le centre de la structure, les micelles se transforment, d'une manière bien définie, en cylindres ou en lamelles élongées. Notamment, on observe le processus inverse à des températures supérieures au point de fusion du polycaprolactone. La seconde partie de cette thèse présente l'utilisation de chaines homopolymères de polycaprolactone, grâce auxquelles il est devenu possible d'obtenir des agrégats lamellaires, semblables à des monocristaux de poly(oxyethylène)-bloc-polycaprolactone, par un processus d'auto-assemblage qui n'a jamais été observé auparavant. En bref, des micelles sphériques contenant ces chaines homopolymères forment, en premier lieu, des cylindres, et l'association latérale de ces cylindres produit des lamelles. L'impact des chaines homopolymères sur la morphologie est décrit en plus de détails dans la section suivante. Un lien est établi entre ces effets et la cristallisation fractionnée dans le centre des micelles: rejetées par la majeure partie du volume cristallin contenu dans la micelle, les chaines homopolymères, par un simple manque d'espace dans une structure aux dimensions nanométriques, s'accumulent près de la surface. Ainsi, les chaines homopolymères facilitent l'adhésion entre les micelles pour en produire soit des cylindres ou des lamelles ayant un taux de cristallinité accru, ce phénomène se produisant même pour des micelles portant en surface des chaines de poly-électrolytes. L'ultime partie de cette thèse se concentre sur l'auto-assemblage de copolymères modifiés au terminus du segment de polycaprolactone. La modification des copolymères n'a aucun effet sur la formation de micelles, ces dernières étant même stabilisées pour ce qui est des changements morphologiques. Cependant, l'observation de la structure interne des micelles a révélé l'organisation spontanée des groupes qui y ont été introduits, pour en former des domaines nanométriques d'une composition chimique différente du reste de la micelle. Dans l'ensemble, le but de cette thèse est de démontrer comment la cristallinité de micelles macromoléculaires peut faire de la morphologie un paramètre dynamique, une relation qui pourrait donner accès à de nouveaux matériaux fonctionnels.

The remarkable molecular recognition specificity of DNA, combined with its structural and biological properties, makes it useful as a programmable and addressable building block for materials science. The materials constructed from nucleic acids have expanded the role of DNA and RNA beyond biology, into a useful component of advanced synthetic materials. The study of DNA self-assembly is rapidly evolving and will most likely find new and unforeseen applications ranging from medicine and biology to nanoelectronics and nano-optics. The error-free and predictable self-assembly of DNA over many length scales is necessary for their use as components of nanodevices and in nanomedicine. The work within this thesis describes an investigation of the self-assembly properties of DNA-macromolecule conjugates with a goal towards predictable long-range order. Conceptually, the work presented in this thesis can be divided into three parts. (1) The first part describes methods to introduce the long-range order achieved by block copolymer assemblies into DNA strands. We present the synthesis of DNA amphiphiles and their hierarchical assembly into nanofibers and ordered networks. (2) In the second part, we use a monodisperse 3D DNA nanoconstruct to direct alkyl chain aggregation below their critical micelle concentration (CMC) through DNA's base pairing ability. (3) The last part describes the hierarchical placement of DNA amphiphiles and of their assemblies along DNA nanotubes. The work described herein offers insight into the synthesis and self-assembly properties of DNA-macromolecule conjugates, and into their hierarchical self-assembly with DNA nanostructures. / En vertu de la fidélité de ses interactions supramoléculaires, ainsi que ses caractéristiques structurales et biologiques, l'ADN est un ajout programmable, contrôlable et, donc, extrêmement utile dans la science des matériaux. Face aux progrès établis dans ce domaine, le rôle de l'ADN et de l'ARN n'est plus restreint qu'à la biologie; en effet, les atouts des acides nucléiques en tant que composants de matériaux synthétiques avancés en sont plusieurs. L'étude de l'auto-assemblage de l'ADN est en évolution vive, axée plutôt vers des réalisations futures au niveau médical, biologique, nano-électronique et nano-optique. Pour que l'ADN adopte un rôle central au sein de la nanotechnologie et la nanomédecine, le contrôle de l'auto-assemblage sur plusieurs échelles de longueur est un prérequis absolu. Le travail réalisé dans cette thèse concerne l'auto-assemblage d'hybrides macromoléculaires d'ADN dans le but de pouvoir organiser ces derniers sur des longueurs au delà du nanométrique. Les concepts seront divisés parmi trois sous-thèmes: (1) La première partie propose des méthodes afin de pourvoir les assemblages de brins d'ADN d'un niveau d'ordre à longue échelle tel que connu chez les copolymères en bloc. Nous présentons la synthèse d'hybrides d'ADN à caractéristiques amphiphiles ainsi que leur assemblage hiérarchique en nano-fibres et en réseaux organisés. (2) Dans la deuxième partie, nous utilisons des assemblages uniformes d'ADN en 3D afin de diriger l'agrégation de chaines alkyles hydrophobiques en dessous de leur concentration micellaire critique (CMC) grâce à la complémentarité de l'ADN. (3) La dernière partie présente le placement hiérarchique de brins d'ADN amphiphiles, ainsi que de leurs assemblages, sur des nanotubes d'ADN. Les principes qui sont sortis de ces travaux démontrent la possibilité de maitriser la synthèse et l'auto-assemblage d'hybrides macromoléculaires d'ADN, ainsi que l'organisation hiérarchique de ceux-ci avec d'autres structures nanométriques à base d'ADN.

Candidate materials for low-loss optical waveguides based on poly(glycidyl methacrylate-ran-pentafluostyrene) (P(GMA-ran-PFS)) copolymers were synthesized by nitroxide mediated polymerization (NMP) initiated with BlocBuilder® (N-(2-methylpropyl)-N-(1-diethlphosphono-2,2-dimethylpropyl)-O-(2-carboxylprop-2-yl) hydroxylamine) bearing a succinimidyl ester group (NHS-BlocBuilder) at 90 oC in 1,4 dioxane. The copolymerizations yielded copolymers with low dispersity between 1.2-1.4. The core structure of single-mode channel waveguides was fabricated by direct UV lithographic patterning. The copolymers with low resulted in line width roughness (LWR) of about 0.16 μm, whereas LWR of copolymers with ~ 3.5 but similar compositions was about 0.5 μm. The improvement in microstructural control allotted by NMP permitted finer pattern replication for copolymers desired for optical waveguides, as suggested for photoresist polymers. / Les matériaux candidats pour des guides d'ondes optiques à faible perte à base de copolymères poly(méthacrylate de glycidyle-ran-pentafluostyrene) (poly(GMA-ran-SSP)) ont été synthétisés par la polymérisation médiée par nitroxyde (NMP) initiée avec BlocBuilder® (N-(2-méthylpropyl)-N-(1-diethlphosphono-2,2-diméthylpropyl)-O-(2-carboxylprop-2-yl) hydroxylamine) portant un groupe d'ester de succinimidyle (NHS-BlocBuilder) à 90 ° C dans du 1,4-dioxane. Les copolymérisations ont donné des copolymères à faible dispersité ( ) entre 1,2-1,4. La structure de base des guides d'ondes canaux monomodes a été fabriqué à l'aide de motifs lithographique par UV directe. Les copolymères de faible ont donné une rugosité à la largeur de ligne (LWR) d'environ 0,16 μm tandis que la LWR des copolymères avec ~3.5 mais de compositions similaires était d'environ 0,5 μm. L'amélioration du contrôle de microstructure attribué par NMP a permis la réplication des motifs plus fins pour les copolymères dont l'utilisation est souhaitée dans les guides d'ondes optiques, tel que suggéré pour les polymères photosensibles.

The in situ, equimolar, trimethylaluminum/H$ sb2$O catalyst was used for the ring opening polymerization of racemic $ beta$-butyrolactone, $ beta$-heptanolactone and $ beta$-nonanolactone to form synthetic analogues of the naturally occurring family of biodegradable poly((R) -$ beta$-hydroxyalkanoate) polymers. This catalyst was found to produce both a better yield and a higher molecular weight of a high isotactic, primarily crystalline fraction of poly($ beta$-(R,S) -hydroxybutyrate) than the conventional in situ, equimolar triethylaluminum/H$ sb2$O catalyst. A mechanically tougher, less isotactic and less crystalline fraction of lower molecular weight and a largely amorphous fraction of even lower molecular weight were also isolated and characterized. / Biodegradation of solid films of synthetic poly($ beta$-(R,S) -hydroxybutyrate) in the presence of an "extracellular" poly($ beta$-(R) -hydroxybutyrate) depolymerase was found to be dependent on accessibility of the enzyme to the (R) linkages along the polymer chain. The semicrystalline fraction was the most susceptible to degradation whereas the high crystallinity fraction showed little degradation and the low crystallinity fraction only showed limited degradation early in the incubation period. / Synthetic poly($ beta$-(R,S) -hydroxyheptanoate) and poly($ beta$-(R,S) -hydroxynonanoate) polyesters were prepared for the first time and the whole product was predominantly isotactic. It was found to have comparable physical properties as the biosynthetic materials, which are only available as terpolymers. Evidence for paracrystalline ordering relating to the organization of the side chains and formation of liquid crystalline-like phases was observed.

The kinetics of the functionalization of linear and cross-linked poly(methyl acrylate) (PMA) and its low-molecular-weight analogs by reactions with various amines in a series of binary solvents or in the solid state have been studied in situ by $ sp{13}$C NMR. Fitting the kinetic data of reactions of PMA with ethanolamine and n-hexylamine (HAN) in DMSO-rich solvent by use of the neighboring-group model shows an auto-acceleration effect due to hydrogen-bonding and/or polar interactions, and hydrophobic interactions; however, PMA and cyclohexane-methylamine shows an auto-retardation effect due to strong steric hindrance. At low extent of reaction the steric effect dominates the kinetics of the reaction of PMA with benzylamine, but hydrophobic interactions become predominant at high extent of reaction. Monomer sequence distributions of the partially functionalized PMA for some of these reactions are not in accord with the predictions of the neighboring-group model, probably due to the long-range neighboring-group effects and/or side reactions. / Despite a pseudo-first order behavior with respect to the concentration of ester groups found for the reaction of cross-linked PMA with HAN, a mono-amine, deviations from first order behavior were also observed for reactions with multi-functional amines. This is due to the formation of extra cross-links, which restrict the diffusion of amines within the polymeric beads, and is confirmed by NMR studies of the chain mobility using the dipolar dephasing technique by the measurement of the decay time constants. / Studies of the binding of bile acid anions by metal-containing polymeric resins, obtained from amine-functionalized PMA and poly(glycidyl methacrylate), show that the type of metal ion and the complexes formed between metal ions and functional groups play a more important role in the binding than factors such as the hydrophobicity of polymer backbones, the structures of functional groups, and the introduction of a spacer between the functional group and the backbone. It is proposed, in addition to the conventional ion exchange process, ligand exchange is involved in the binding mechanism. This is confirmed by results of $ sp{15}$N NMR and proton spin-lattice relaxation time experiments.

Layer thickness measurements are used to investigate polymer adsorption and possible conformations of adsorbed polymer. / In a first step, photon correlation spectroscopy (PCS) is used to monitor the layer thickness at different ratios of polyethylene oxide (PEO) per polystyrene (PS) latex spheres. Comparison of the polymer concentration at which the equilibrium layer thickness was attained with the concentration where the adsorption isotherm reached its plateau leads to a proposed three step adsorption process. Kinetic studies of the layer thickness build-up also support this mechanism. Polymer polydispersity and the effect of anchored end groups on layer thickness are found to be in agreement with theoretical predictions. / In a second step, a rheological investigation of PEO coated polystyrene-butadiene (PSB) latex spheres was performed. The influence of coating on the second virial coefficient was determined. Comparison of the layer thickness as measured by viscosity and PCS shows the relative importance of the latex polydispersity for the two methods.

Ammonium-containing polyacrylamide resins, ammonium-containing polystyrene resins, and their metal-ion coordinated analogs have been synthesized for the sorption of bile salts (BS). The effects of altering the backbone, the type of ammonium group, the number of ammonium group, the hydrophobicity of the pendant group, and of varying the metal ions on the adsorption of BS's, were studied to elucidate the structure-activity relationship. / The binding capacity of the resins for BS's generally increased with increasing number of ammonium groups per pendant group of the ammonium-bearing resins, and with higher charge of the metal complex cation of the metal-ion coordinated resin, demonstrating the primary importance of electrostatic interactions. It was also observed that, as the resin backbone was changed from hydrophilic polyacrylamide to hydrophobic polystyrene, the adsorption capacity increased substantially, demonstrating that hydrophobic interactions (H-H's) between the resin backbone and the BS's also play a significant role in the binding. The incorporation of hydrophobic segments -(CH$ sb2) sb{ rm n}$- into the pendant groups on polyacrylamide resins increased binding capacity, but had no effect for the more hydrophobic polystyrene resins. Primary ammonium-bearing resins often showed higher binding capacities than their quarternary analogs, suggesting that H-bonding reinforces the binding. Isotherms with an S-shape observed for most polyacrylamide resins indicate a positive cooperativity in the binding due to H-H's and H-bonding among BS anions bound at adjacent positions within resin beads. Binding models have been proposed to depict the formation of pendant group-BS mixed reversed micelles and ordinary BS micelles. / The studies of the kinetics of the binding of BS anions by the resins showed that a small resin particle size and more intense shaking substantially increase the rate of binding. This indicates that the binding process is mainly controlled by the diffusion of BS anions near and within the beads. (Abstract shortened by UMI.)

This thesis presents the results of several studies, the overall goal of which was the design and understanding of a block copolymer micelle in which the coronal chains act as a catalyst support for organometallic species. A model system consisting of reverse micelles of polystyrene-block -poly (sodium acrylate), PS-b-PANa, with coronal chain composed of ca. 210 styrene repeat units and a core radius of ca. 3.0 nm was used in the first study. The coronal chains were loaded to varying extents with Cr(CO)3 fragments in an effort to observe the effect of loading on the corona. The hydrodynamic radii, Rh, were measured by dynamic light scattering, DLS, and compared to a similarly treated sample of PS homopolymer. An increase in Rh by a factor of 3.4 was observed in the micelles, compared to only 1.5 in the homopolymer. A new block copolymer aggregate consisting of Poly (4-bromostyrene)-block-poly(4-vinylphenol), PBS- b-P4VPOH, in which the P4VPOH block could be used to crosslink the core, was developed for use as a coronal support for catalytically active organometallic species. bis-dimethylaminodimethylsilane was used to generate a crosslinked network of siloxane linkages within the core, resulting in a stable micelle. KPPh2 was then reacted with the PBS corona of the micelle to convert the bromostyrene units to analogues of triphenylphosphine. These micelles were then successfully loaded with a rhodium based catalyst. Catalytic activity was tested using the hydrogenation of 1-decene as a model reaction, in which turn-over frequencies of ca. 130 were achieved. The expansion seen in the first study also prompted an effort to develop a theoretical model of coronal chain behavior. A combined hypernetted-chain, mean spherical, Monte-Carlo method was used to model the corona of a micelle. The potential governing the interactions between repeat units was modified to include the effect of having several different species present along the chains. Th

The main objective of the present thesis is to prepare bactericidal filter paper by employing hydrophobic biocides of very low water solubility. To achieve this goal, two different strategies were proposed. One involves the use of amphiphilic block copolymer micelles which serve as a carrier for loaded biocides, and are subsequently attached to the pulp fibres; the other utilizes biocide emulsions stabilized with polymeric materials. As a part of first strategy, the mechanisms of loading of biocide into and release from the block copolymer micelles of poly(styrene)-b-poly(acrylic acid) were elucidated. It was found that loading is a two step process; first, the micelle surface is saturated with biocide molecules. In the next step, the biocide penetrates as a front into the hydrophobic polystyrene core, while lowering the glass transition temperature of the polystyrene. The release of the biocide from the micelles was found to be a slower process than loading; the rate determining step of the release is the removal of the biocide molecules from the surface of the micelles, since the biocide molecules have to pass over an energy barrier to go into the aqueous solution. E. coli bacteria deactivation by biocide loaded micelles in solution was studied next. As a main conclusion, it was found that block copolymer micelles loaded with triclosan biocide are efficient in deactivating the bacteria in less than two minutes. Also, the mechanism of biocide uptake by the bacteria was elucidated, which involves transfer of biocide molecules during transient collisions between loaded micelles and bacteria. An antibacterial filter paper was prepared by modifying commercial filter papers or paper towels by changing the natural negative charge of the pulp fibres to positive by adsorption of cationic poly(acryl)amide, followed by attachment of negatively charged biocide loaded micelles to the pulp fibres. After passage through the modified filter paper, the bacteria were found to be / L'objectif principal de la présente thèse est de préparer un papier filtre bactéricide en employant des biocides hydrophobiques ayant une très faible solubilité dans l'eau. Pour atteindre ce but, deux différentes stratégies furent proposées. L'une implique l'utilisation de micelles de copolymère bloc amphiphiles qui servent au transport de biocides dopés, et sont subséquemment attachées aux fibres de pâte; l'autre utilise des émulsions biocides stabilisées avec des matériaux polymères. Comme partie de la première stratégie, les mécanismes de dopage du biocide ainsi que de la libération des micelles de copolymère bloc de poly(styrène)-b-poly(acide acrylique) furent élucidés. Il fut découvert que le dopage est un processus à deux étapes; premièrement, la surface de la micelle est saturée avec des molécules biocides. Dans l'étape qui suit, le biocide pénètre de front dans le cœur hydrophobique de polystyrène, diminuant la température de transition vitreuse du polystyrène. La libération du biocide des micelles fut déterminée comme étant un processus plus lent que celui du dopage; l'étape déterminante de la vitesse de libération est l'enlèvement des molécules biocides de la surface des micelles, étant donné que les molécules de biocide doivent passer au-dessus d'une barrière énergétique pour aller dans la solution aqueuse. La désactivation de bactéries E. coli par les micelles dopées de biocide en solution fut ensuite étudiée. Comme conclusion générale, il fut découvert que les micelles de copolymère bloc dopées avec le biocide triclosan sont efficaces pour désactiver les bactéries en moins de deux minutes. Aussi, le mécanisme de consommation du biocide par les bactéries fut élucidé, impliquant le transfert des molécules de biocide durant les collisions transitoires entre les micelles dopées et les bactéries. Un papier filtre antibactérien fut préparé en modifiant des papiers filtres commercia

The goal of this thesis was to synthesize two poly(lactic acid)-co-poly(ethylene glycol) biodegradable amphiphilic block copolymers that can self-assemble in an aqueous environment into a micellar morphology. Also, the physicochemical characteristics of both the copolymers and resultant micelles were studied using a variety of chemical characterization techniques to gain insight into the factors that are important in the formation and function of the micelles. Two copolymers were synthesized which had different sizes and relative block lengths. These copolymers were characterized using NMR spectroscopy, gel permeation chromatography and thermogravimetric analysis. With these two polymers the self-assembly conditions which lead to the most narrow size distribution as determined by dynamic light scattering, were found and micelles were characterized by scanning electron microscopy, and through the partitioning of pyrene between the core of the micelles and water. Finally, an investigation of the time scales of micelle degradation was performed by monitoring a solution of micelles over an extended period of time.