In this project, the sensitivity of the phase behaviour of AB diblock copolymers to the addition a single C-monomer is investigated using self-consistent mean-field theory. The reference diblock copolymers are composed of the minority A block with N_A = 12 monomers and the majority B block with N_B monomers. The blocks are mutually repulsive and their interaction is characterised by χ_{ij} and acts over range σ_{ij}, where i and j represent the monomer species. When a C-monomer is added to the junction of the diblock copolymers, we observe a notable shift of the phase boundaries to the larger NB and smaller χ_{AB}. The shift to larger NB is due to an increased polymer stretching. When the C-monomers is nearly-neutral, the shift does not strongly depend on the interaction strength. Similarly, the shift is not visibly affected by changing σ_{AC} and σ_{BC}. However, when the the strength of the interaction is selective such that χ_{AC} = χ_{AB} + α and χ_{BC} = χ_{AB} − α, the shift size decreases with increasing α. Conversely, when the selective C-monomer is added to the majority end, the phase boundaries are shifted to the smaller N_B, with the smallest α giving the largest shift. The shifts can be generically understood to be cause by the interplay between the changes in the interfacial tension and polymer stretching due to the C-monomer. These results demonstrate sensitivity of phase behaviour of AB diblock copolymers to the addition of a C-monomer and may provide a useful link between experiment and theory. / Thesis / Master of Science (MSc)

The Reversible Addition Fragmentation Chain Transfer (RAFT) process using the new RAFT agent benzyldithiophenyl acetate is shown to be a powerful polymerization tool to synthesize novel well-defined amphiphilic diblock copolymers composed of the constant hydrophobic block poly(butyl acrylate) and of 6 different hydrophilic blocks with various polarities, namely a series of non-ionic, non-ionic comb-like, anionic and cationic hydrophilic blocks. The controlled character of the polymerizations was supported by the linear increase of the molar masses with conversion, monomodal molar mass distributions with low polydispersities and high degrees of end-group functionalization. <br><br> The new macro-surfactants form micelles in water, whose size and geometry strongly depend on their composition, according to dynamic and static light scattering measurements. The micellization is shown to be thermodynamically favored, due to the high incompatibility of the blocks as indicated by thermal analysis of the block copolymers in bulk. The thermodynamic state in solution is found to be in the strong or super strong segregation limit. Nevertheless, due to the low glass transition temperature of the core-forming block, unimer exchange occurs between the micelles. Despite the dynamic character of the polymeric micellar systems, the aggregation behavior is strongly dependent on the history of the sample, i.e., on the preparation conditions. The aqueous micelles exhibit high stability upon temperature cycles, except for an irreversibly precipitating block copolymer containing a hydrophilic block exhibiting a lower critical solution temperature (LCST). Their exceptional stability upon dilution indicates very low critical micelle concentrations (CMC) (below 4∙10^-4 g∙L^-1). All non-ionic copolymers with sufficiently long solvophobic blocks aggregated into direct micelles in DMSO, too. Additionally, a new low-toxic highly hydrophilic sulfoxide block enables the formation of inverse micelles in organic solvents. <br><br> The high potential of the new polymeric surfactants for many applications is demonstrated, in comparison to reference surfactants. The diblock copolymers are weakly surface-active, as indicated by the graduate decrease of the surface tension of their aqueous solutions with increasing concentration. No CMC could be detected. Their surface properties at the air/water interface confer anti-foaming properties. The macro-surfactants synthesized are surface-active at the interface between two liquid phases, too, since they are able to stabilize emulsions. The polymeric micelles are shown to exhibit a high ability to solubilize hydrophobic substances in water. / Amphiphile sind Moleküle, die aus einem hydrophilen und einem hydrophoben Molekülteil aufgebaut sind. Beispiele für Amphiphile sind Tenside, deren makromolekulares Pendant amphiphile Block-Copolymere sind, die häufig auch als Makro-Tenside bezeichnet sind. Ihre Lösungseigenschaften in einem selektiven Lösungsmittel, i.e., ein für einen Block gutes und für den anderen schlechtes Lösungsmittel, sind analog zu denen von Tensiden. Die Unverträglichkeit der Polymersegmente führt zu einer von hydrophoben Wechselwirkungen getriebenen Mikrophasenseparation, d.h. zur Selbstorganisation der amphiphilen Makromoleküle zu Mizellen unterschiedlichster Form, während die kovalente Bindung zwischen den Blöcken eine Makrophasenseparation verhindert. Aufgrund ihres besonderen strukturellen Aufbaus adsorbieren Makro-Tenside an Grenzflächen, was zahlreiche Anwendungen, z.B. zur (elektro)sterischen Stabilisierung von Emulsionen und Dispersionen findet. <br><br> Die vorliegende Arbeit demonstriert, dass die neuen kontrollierten radikalischen Polymerisationen wie die RAFT-Methode („Reversible Addition Fragmentation Chain Transfer“) für die Synthese von neuen wohldefinierten amphiphilen Diblock-Copolymerstrukturen sehr gut geeignet sind. Eine Reihe von neuen amphiphilen Diblock-Copolymeren wurde mittels RAFT synthetisiert, mit einem konstanten hydrophoben Block und verschiedenen hydrophilen Blöcken unterschiedlichster Polaritäten. Die engen Molmassenverteilungen und der lineare Aufstieg der Molmassen mit dem Umsatz belegen den kontrollierten Charakter der Polymerisation. <br><br> Die thermodynamisch favorisierte Selbstorganisation der synthetisierten Blockcopolymere in Wasser führt zur Bildung von Mizellen, deren Eigenschaften aber von der Präparationsmethode stark abhängig sind. Korrelationen zwischen den Mizelleigenschaften und der Blockcopolymerstruktur zeigen, dass die Mizellgröße vor allem von der Länge des hydrophoben Blocks kontrolliert wird, wohindagegen die Natur des hydrophilen Blocks der entscheidende Faktor für die Mizellgeometrie ist. Die gebildeten Mizellen sind besonders stabil gegenüber Verdünnung und Temperaturzyklen, was ein großer Vorteil für eventuelle Anwendungen ist. Wegen der niedrigen Glasübergangstemperatur des hydrophoben Blocks findet ein Austausch von Makromolekülen zwischen den Mizellen statt, d.h. es handelt sich um dynamische Mizellsysteme. <br><br> Das Potential der neuen Makrotenside für Anwendungen wurde untersucht. Die Polymermizellen zeigen eine hohe Kapazität wasserunlösliche Substanzen in Wasser zu solubilisieren. Die Blockcopolymere sind grenzflächenaktiv, d.h. sie adsorbieren an Wasser / Luft oder Wasser / Öl Grenzflächen. Entsprechend sind die Blockcopolymere in der Lage, Emulsionen zu stabilisieren oder als Antischaumsubstanzen zu wirken.

In order to optimize the synthesis of metal nanoparticle-polymer systems, there are certain processes which must be understood. Perhaps the most important one is the selective interfacial interaction between the block copolymer and the growing metal nanoparticles. To investigate this interaction, four different approaches were taken. The first approach looked at the strength of interaction between the competing blocks of the copolymer and the metal nanoparticles surface. The second approach looked at the effect of polymer architecture on the metal nanoclusters. The third approach looked at the polymer composition and solvent effects on the phase behavior of the metal nanocluster-block copolymer nanocomposite. Finally, the influence of the metal precursor on the rate of the decomposition was examined. It was found that adsorbed layers of PS on the cobalt nanoparticles are completely displaced by PMMA when the solvent is a common good solvent. An adsorbed layer of only PMMA is also obtained through competitive adsorption from a common good solvent. However, in a selective solvent that is poor for PS, sequential adsorption leads to the formation of mixed layers. In homopolymer solutions, the cluster size reaches a minimum at a finite chain MW. In the case of diblock copolymers, the only parameter (for a fixed copolymer concentration) controlling the cluster size in suspensions of di-block copolymers is the molecular weight of one block, in this case PMMA, and is indifferent to other parameters including the molecular weight of the other block (PS) or the solvent quality. It was also found that the spatial distribution of the metal clusters synthesized in-situ coincided with the morphology dictated by thermodynamically-driven microdomain structure of the block copolymer. Moreover, the overall final morphology of the nanocomposite is locked into place while in solution, and fast solvent evaporation does not cause this morphology to change. Finally, results showed that the rate of nanocomposite synthesis occurred faster in the PS suspensions compared to PMMA, indicating that chemical bonds between PMMA and the cobalt nanoclusters slowed the thermal decomposition of the metal precursor. So the PMMA chains provided sites for nucleation, but did not necessarily aid particle growth.

In this thesis detailed investigations of the phase behavior of poly(n-alkyl methacrylate-b-methyl methacrylate) diblock copolymers and its influence on the wettability of the polymer surfaces were carried out. For this investigation two polymethacrylic systems differing only in the alkyl rest of one block: poly(pentyl methacrylate-b-methyl methacrylate) and poly(propyl methacrylate-b-methyl methacrylate) have been chosen in order to prove how this substituent affects the phase behavior of whole system. The PnAlkMA-b-PMMA diblock copolymers in a wide range of molar masses, and with varied block length ratios were synthesized by living anionic polymerization. The syntheses were carried out in tetrahydrofuran (THF), at –78 °C, by using sec-buthyllithium as initiator, in the presence of lithium chloride (LiCl). Under these conditions highly syndiotactic products, rr ~ 0.82, with very narrow molar mass distribution, Mw/Mn ~ 1.1, were obtained. The phase behavior of PnAlkMA-b-PMMA diblock copolymers in bulk was investigated by means of DSC and SAXS measurements. The DSC analysis revealed that the PPMA-b-PMMA with weight fractions of PPMA, fPPMA, from 0.28 up to 0.86 showed two separate Tg’s, indicative of a phase separated system. However, by comparing the Tg’s of the diblock copolymers with the Tg’s of the corresponding homopolymers we found that in a few cases, mostly for samples with the high molar masses, they were slightly shifted. This finding pointed out the existence of two mixed phases, and hence partial miscibility between the both blocks was assumed. The SAXS patterns reflected for most diblock copolymers lamellae morphologies even in the case of very asymmetric composition, for instance with volume fraction of PPMA, 0.86 It was assumed that this behavior is caused by the chemical similarity of both blocks as well as by the differences in their molar volumes. The SAXS findings were further confirmed by the AFM measurements on the cutted “bulk” samples. From the solubility concept of Van Krevelen we obtained that the interaction parameter of PPMA-b-PMMA is rather low, 0.065, compared to the other well-known diblock copolymers. The calculated spinodals are characterized by a high asymmetry. The investigation of the phase behavior of PPMA-b-PMMA in thin films showed that the morphology as well as the topography of the thin films were strongly affected by the film thickness, when the films were prepared from a non-selective solvent (THF) onto silicon wafers. Well-recognizable nanostructures with long-range order were mainly found in thin films of diblock copolymers with high molar masses, above 100,000 g/mol, and with a high amount of PPMA. The lateral domain spacing obtained for these films from AFM corresponded well with that found in bulk. The study of the influence of the thermal as well as vapor annealing on the morphology and topography of the thin films provided additional information about the phase behavior of PPMA-b-PMMA diblock copolymers in thin films. Finally, the wettability of the investigated PPMA-b-PMMA surfaces was established by means of contact angle measurements. The measured contact angles were in most cases even on nicely nanostructured surfaces very similar to the contact angle of PPMA, indicating preferential segregation of PPMA to the film surface. Additional XPS measurements also showed an enrichment of the PPMA at the surface, independent of the morphology observed by AFM, and thereby confirmed the ADSA finding. In the next part of this work, investigations of the phase behavior of PPrMA-b-PMMA diblock copolymers were presented. In the contrary to the previous system the PPrMA-b-PMMA showed mostly a single Tg, which was further found to be depend on the weight fraction of PPrMA, fPPrMA. The SAXS data revealed that the PPrMA-b-PMMA diblock copolymers were phase separated in bulk, however the obtained scattering patterns exhibited mostly broad, not-well discernible higher-order peaks. Nevertheless, it was possible to identify the formed morphologies and depending on the volume fraction of PPrMA, hexagonally packed cylinders and lamellae were detected. The PPrMA-b-PMMA is characterized by a significantly lower value of the interaction parameter, 0.022, than the PPMA-b-PMMA system. This difference clearly reflects the weakening of the interactions between the components with decrease of the length of the alkyl side chain. The thin films of PPrMA-b-PMMA diblock copolymers appeared mostly smooth and featureless, independent of the film thickness. From the contact angle and XPS measurements we obtained, that unlike the PPMA-b-PMMA, both components were always present on the top of the surface. / In der vorliegenden Arbeit wurden Untersuchungen zum Entmischungsverhalten von Poly(n-alkylmethacrylat-b-methylmethacrylat) Diblockcopolymeren und deren Einfluss auf die Benetzbarkeit der Polymeroberflächen dargestellt. Diese Untersuchungen wurden anhand der Poly(pentylmethacrylat-b-methylmethacrylat) und Poly(propylmethacrylat-b-methylmethacrylat) durchgeführt. Die Diblockcopolymere in einem weiten Molmassenbereich, mit enger Molmassenverteilung, abgestuften Zusammensetzung wurden erfolgreich mittels anionischer Polymerization synthetisiert. Die Synthese erfolgte in THF bei (-78 °C) in Gegenwart von Lithiumchlorid. Als Initiator wurde sec. Butyllithium genutzt. Das Phasenverhalten der Diblockcopolymere im Festkörper wurde mittels DSC und SAXS untersucht. Für die meiste PPMA-b-PMMA Diblockcopolymere wurden mittels DSC zwei getrennte Tg gefunden, die aber im Vergleich zu den Tg von den entsprechenden Homopolymeren leicht verschoben waren. Es wurde also eine partielle Mischbarkeit der Blöcke festgestellt. Mittels SAXS-Untersuchungen wurde für die Mehrzahl der Diblckcopolymere in einem weiten Zusammensetzungsbereich bis zum 0.86 Volumenanteil von PPMA, eine lamellare Anordnung beobachten. Diese Befunde wurden nachfolgend mit AFM–Untersuchungen an dünnen Polymerfolien bestätigt. Das mit der Mean-Filed-Methode berechnete Phasendiagramm zeigte eine Asymmetrie, die durch die Unterschiede in den molaren Volumina des Blöckes verursacht war. Es wurde aber eine gute Übereinstimmung mit der experimentell erhaltenen Daten gefunden. Der berechnete für das System Wechselwirkungsparameter beträgt 0,065. Die AFM-Untersuchungen zum Entmischungsverhalten in dünnen Filmen haben gezeigt, dass die Topographie als auch Morphologie des Films war von der Filmdicke beeinflusst. Die Polymerfilme wurden mittels dipcoating der Si-Wafer präpariert. Dazu wurden Polymerlösungen in THF verwendet. Reguläre Nanostrukturen, deren Abstände mit dem im Festkörper gefundenen sehr gut übereinstimmten, wurden bei den Proben mit höherem Anteil von PPMA erhalten. Es wurden auch der Einfluss der Temperatur und der Dampfbehandlung auf die Morphologie und Topographie des Films untersucht. Die Benetzbarkeit der untersuchte PPMA-b-PMMA Filme wurde mit der Kontaktwinkelmessungen (ADSA) bestimmt. Als Messflüssigkeit wurde Milipore Wasser genutzt. Für die Mehrzahl der Diblockcopolymere wurden Kontaktwinkel im Bereich um 95° ermitteln, unabhängig von der Zusammensetzung der Diblockcopolymere und der vorhandenen Nanostruktur. Dies entspricht dem Kontaktwinkel von PPMA Homopolymer. Die Benetzbarkeit der PPMA-b-PMMA Filme wurde also durch die Oberflächensegregation des Niedrigenergieblocks (PPMA) bestimmt. Dies wurde danach durch zusätzliche XPS Messungen bestätigt. Im Vergleich zu PPMA-b-PMMA, die nachfolgend untersuchte PPrMA-b-PMMA Diblockcopolymere wiesen eine höhere Tendenz zur Mischbarkeit auf. Anhand der DSC–Untersuchungen wurde hier vorübergehend eine Misch-Tg gefunden. Nur bei der Probe mit symmetrischer Zusammensetzung wurden zwei getrennte Tg beobachtet. Die Streukurven von diesem System waren sehr schwach ausgeprägt. Dadurch die Indizierung der vorhandenen Morphologien war nicht eindeutlich. Der berechnete Wechselwirkungsparameter beträgt 0,022. Bei den AFM-Untersuchungen zum Entmischungsverhalten in dünnen PPrMA-b-PMMA Filmen wurden entweder keine oder sehr schwach geordnete Nanostruktur gefunden. Im Gegensatz zu dem vorherigen System, die Benetzbarkeit der PPrMA-b-PMMA Filme war durch die Zusammensetzung der Diblockcopolymere bedingt.

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (p. 114-121).

This thesis reports the fabrication of nanophotonic structures by using electron beam lithography and using pattern transfer via self assembly with the aid of block copolymers. A theoretical and experimental basis was developed for fabricating anti-reflective coatings using block-copolymer pattern transfer. Block-copolymers were also used to fabricate plasmonic pattern arrays which form gold dots on glass surface. Electron-beam lithography was utilized to fabricate holey plasmonic structures from gold and silver films. Electron-beam exposure was used in block-copolymer lithography in selected regions. The exposure effects were studied for both thin and thick block-copolymer films. Reactive and ion beam etching techniques were used and optimized to fabricate those structures. This research required a great deal of development of new fabrication methods and key information is included in the body of the thesis.

Well-defined heterobifunctional homopolyethers and amphiphilic block copolyethers containing a variety of functionalities were designed, synthesized, and characterized via GPC and 1H NMR. These have included controlled molecular weight cholesterol-PEO-OH, mono- and trivinylsilyl-PEO-OH, monovinylsilyl-PEO-PPO-OH, monovinylsilyl-PEO-PPO-PEO-OH, maleimide-PEO-OH, stearyl alcohol-PEO-OH, propargyl alcohol-PEO-OH, trivinylsilyl-PPO-OH, trivinylsilyl-PPO-PEO-OH, and benzyl alcohol-initiated poly(allyl glycidyl ether)-OH. The focus of polymers utilized in this study involved the mono- and trivinylsilyl polyethers. The vinylsilyl endgroups on these materials were functionalized with various bifunctional thiols through free radical addition of SH groups across the vinylsilyl double bonds. The resultant end-functional polyethers were adsorbed onto magnetite nanoparticles and the stabilities of the polymer-magnetite complexes were compared as a function of the type of anchoring moiety and the number of anchoring moieties per chain. Anchoring chemistries investigated in this work included carboxylates, alkylammonium ions, and zwitterionic phosphonates. The anchor group-magnetite bond stability was investigated in water and phosphate buffered saline (PBS). Through these studies, the zwitterionic phosphonate group was shown to be a better anchoring group for magnetite than either carboxylate or ammonium ions. Tri-zwitterionic phosphonate anchor groups provided stability of the complexes in PBS for a broad range of polymer loadings. Thus, investigations into the stability of polyether-magnetite complexes in PBS focused on hydrophilic zwitterionic phosphonate-PEO-OH and amphiphilic zwitterionic phosphonate-PPO-b-PEO-OH oligomer coatings on the surface of magnetite. Superparamagnetic magnetite nanoparticles are of interest as potential contrast-enhancement agents for MRI imaging. Thus, transverse NMR relaxivities of these complexes were studied as a function of chemical composition and nanostructure size and compared to commercial contrast agents. The amphiphilic polyether-magnetite nanoparticles were shown to be stable in both aqueous media as well as physiological media and have much higher transverse relaxation values, r2, than those of commercial contrast agents and other materials in the literature. / Ph. D.

[pt] O presente estudo investiga a estrutura e a potencial aplicação de nanopartículas formadas por copolímeros que possuem um bloco neutro e outro bloco aniônico combinados a um surfactante catiônico. Em água, os blocos aniônicos se complexam eletrostaticamente às micelas de surfactante, interconectando-as e formando um núcleo concentrado, que pode até apresentar estrutura líquido-cristalina. Os blocos neutros são hidrofílicos e por isso formam uma casca que estabiliza as nanopartículas em água. Devido à formação do núcleo concentrado de micelas, espera-se que estas nanopartículas sejam capazes de incorporar uma maior quantidade de moléculas hidrofóbicas em comparação a micelas de surfactante puro na mesma concentração. Os resultados indicam que quanto mais longo é o bloco aniônico, mais alta é a incorporação das moléculas hidrofóbicas. Por outro lado, o bloco neutro tem um papel importante para aumentar a estabilidade das nanopartículas em meio aquoso. A incorporação de moléculas hidrofóbicas no núcleo das nanopartículas causa alterações na organização das micelas, levando à formação de diferentes estruturas líquido-cristalinas ou a alterações nas distâncias de correlação. Com base nas propriedades das nanopartículas, foi proposta uma formulação aquosa capaz de incorporar uma quantidade significativa de um filtro solar orgânico. Com os resultados obtidos para esta formulação, foi possível demonstrar sua eficácia em evitar a degradação de cabelos por irradiação ultravioleta, o que torna este sistema um candidato de alto potencial para aplicação na indústria de cosméticos. / [en] The present study investigates the structure and potential application of core-shell nanoparticles formed by block copolymers (consisted of an anionic and a neutral blocks) and a cationic surfactant. In water, the anionic blocks electrostatically complex to the surfactant micelles, interconnecting them and forming a concentrated nucleus, which may form even liquid-crystalline structures. Because the neutral blocks are hydrophilic, they form a shell which stabilizes the nanoparticles in water. The concentrated nuclei of micelles are expected to uptake a higher amount of hydrophobic molecules than the regular micelles of pure surfactant in the same concentration. The longer is the anionic block forming the nucleus, the higher is the uptake of hydrophobic substances. On the other hand, the neutral block plays a key role to increase nanoparticle stability in aqueous medium. The uptake of hydrophobic molecules increased the ordering of the micelles in the nucleus, leading either to the formation of different liquid-crystalline structures or to variations in the correlation distances. Taking these results in to account, we proposed an aqueous formulation with a considerable uptake capacity of an organic sunscreen. The results obtained for this formulation demonstrate its efficacy to avoid hair degradation by ultraviolet radiation exposition, which make this system a potential candidate for applications in the cosmetic industry.

In this thesis detailed investigations of the phase behavior of poly(n-alkyl methacrylate-b-methyl methacrylate) diblock copolymers and its influence on the wettability of the polymer surfaces were carried out. For this investigation two polymethacrylic systems differing only in the alkyl rest of one block: poly(pentyl methacrylate-b-methyl methacrylate) and poly(propyl methacrylate-b-methyl methacrylate) have been chosen in order to prove how this substituent affects the phase behavior of whole system. The PnAlkMA-b-PMMA diblock copolymers in a wide range of molar masses, and with varied block length ratios were synthesized by living anionic polymerization. The syntheses were carried out in tetrahydrofuran (THF), at –78 °C, by using sec-buthyllithium as initiator, in the presence of lithium chloride (LiCl). Under these conditions highly syndiotactic products, rr ~ 0.82, with very narrow molar mass distribution, Mw/Mn ~ 1.1, were obtained. The phase behavior of PnAlkMA-b-PMMA diblock copolymers in bulk was investigated by means of DSC and SAXS measurements. The DSC analysis revealed that the PPMA-b-PMMA with weight fractions of PPMA, fPPMA, from 0.28 up to 0.86 showed two separate Tg’s, indicative of a phase separated system. However, by comparing the Tg’s of the diblock copolymers with the Tg’s of the corresponding homopolymers we found that in a few cases, mostly for samples with the high molar masses, they were slightly shifted. This finding pointed out the existence of two mixed phases, and hence partial miscibility between the both blocks was assumed. The SAXS patterns reflected for most diblock copolymers lamellae morphologies even in the case of very asymmetric composition, for instance with volume fraction of PPMA, 0.86 It was assumed that this behavior is caused by the chemical similarity of both blocks as well as by the differences in their molar volumes. The SAXS findings were further confirmed by the AFM measurements on the cutted “bulk” samples. From the solubility concept of Van Krevelen we obtained that the interaction parameter of PPMA-b-PMMA is rather low, 0.065, compared to the other well-known diblock copolymers. The calculated spinodals are characterized by a high asymmetry. The investigation of the phase behavior of PPMA-b-PMMA in thin films showed that the morphology as well as the topography of the thin films were strongly affected by the film thickness, when the films were prepared from a non-selective solvent (THF) onto silicon wafers. Well-recognizable nanostructures with long-range order were mainly found in thin films of diblock copolymers with high molar masses, above 100,000 g/mol, and with a high amount of PPMA. The lateral domain spacing obtained for these films from AFM corresponded well with that found in bulk. The study of the influence of the thermal as well as vapor annealing on the morphology and topography of the thin films provided additional information about the phase behavior of PPMA-b-PMMA diblock copolymers in thin films. Finally, the wettability of the investigated PPMA-b-PMMA surfaces was established by means of contact angle measurements. The measured contact angles were in most cases even on nicely nanostructured surfaces very similar to the contact angle of PPMA, indicating preferential segregation of PPMA to the film surface. Additional XPS measurements also showed an enrichment of the PPMA at the surface, independent of the morphology observed by AFM, and thereby confirmed the ADSA finding. In the next part of this work, investigations of the phase behavior of PPrMA-b-PMMA diblock copolymers were presented. In the contrary to the previous system the PPrMA-b-PMMA showed mostly a single Tg, which was further found to be depend on the weight fraction of PPrMA, fPPrMA. The SAXS data revealed that the PPrMA-b-PMMA diblock copolymers were phase separated in bulk, however the obtained scattering patterns exhibited mostly broad, not-well discernible higher-order peaks. Nevertheless, it was possible to identify the formed morphologies and depending on the volume fraction of PPrMA, hexagonally packed cylinders and lamellae were detected. The PPrMA-b-PMMA is characterized by a significantly lower value of the interaction parameter, 0.022, than the PPMA-b-PMMA system. This difference clearly reflects the weakening of the interactions between the components with decrease of the length of the alkyl side chain. The thin films of PPrMA-b-PMMA diblock copolymers appeared mostly smooth and featureless, independent of the film thickness. From the contact angle and XPS measurements we obtained, that unlike the PPMA-b-PMMA, both components were always present on the top of the surface. / In der vorliegenden Arbeit wurden Untersuchungen zum Entmischungsverhalten von Poly(n-alkylmethacrylat-b-methylmethacrylat) Diblockcopolymeren und deren Einfluss auf die Benetzbarkeit der Polymeroberflächen dargestellt. Diese Untersuchungen wurden anhand der Poly(pentylmethacrylat-b-methylmethacrylat) und Poly(propylmethacrylat-b-methylmethacrylat) durchgeführt. Die Diblockcopolymere in einem weiten Molmassenbereich, mit enger Molmassenverteilung, abgestuften Zusammensetzung wurden erfolgreich mittels anionischer Polymerization synthetisiert. Die Synthese erfolgte in THF bei (-78 °C) in Gegenwart von Lithiumchlorid. Als Initiator wurde sec. Butyllithium genutzt. Das Phasenverhalten der Diblockcopolymere im Festkörper wurde mittels DSC und SAXS untersucht. Für die meiste PPMA-b-PMMA Diblockcopolymere wurden mittels DSC zwei getrennte Tg gefunden, die aber im Vergleich zu den Tg von den entsprechenden Homopolymeren leicht verschoben waren. Es wurde also eine partielle Mischbarkeit der Blöcke festgestellt. Mittels SAXS-Untersuchungen wurde für die Mehrzahl der Diblckcopolymere in einem weiten Zusammensetzungsbereich bis zum 0.86 Volumenanteil von PPMA, eine lamellare Anordnung beobachten. Diese Befunde wurden nachfolgend mit AFM–Untersuchungen an dünnen Polymerfolien bestätigt. Das mit der Mean-Filed-Methode berechnete Phasendiagramm zeigte eine Asymmetrie, die durch die Unterschiede in den molaren Volumina des Blöckes verursacht war. Es wurde aber eine gute Übereinstimmung mit der experimentell erhaltenen Daten gefunden. Der berechnete für das System Wechselwirkungsparameter beträgt 0,065. Die AFM-Untersuchungen zum Entmischungsverhalten in dünnen Filmen haben gezeigt, dass die Topographie als auch Morphologie des Films war von der Filmdicke beeinflusst. Die Polymerfilme wurden mittels dipcoating der Si-Wafer präpariert. Dazu wurden Polymerlösungen in THF verwendet. Reguläre Nanostrukturen, deren Abstände mit dem im Festkörper gefundenen sehr gut übereinstimmten, wurden bei den Proben mit höherem Anteil von PPMA erhalten. Es wurden auch der Einfluss der Temperatur und der Dampfbehandlung auf die Morphologie und Topographie des Films untersucht. Die Benetzbarkeit der untersuchte PPMA-b-PMMA Filme wurde mit der Kontaktwinkelmessungen (ADSA) bestimmt. Als Messflüssigkeit wurde Milipore Wasser genutzt. Für die Mehrzahl der Diblockcopolymere wurden Kontaktwinkel im Bereich um 95° ermitteln, unabhängig von der Zusammensetzung der Diblockcopolymere und der vorhandenen Nanostruktur. Dies entspricht dem Kontaktwinkel von PPMA Homopolymer. Die Benetzbarkeit der PPMA-b-PMMA Filme wurde also durch die Oberflächensegregation des Niedrigenergieblocks (PPMA) bestimmt. Dies wurde danach durch zusätzliche XPS Messungen bestätigt. Im Vergleich zu PPMA-b-PMMA, die nachfolgend untersuchte PPrMA-b-PMMA Diblockcopolymere wiesen eine höhere Tendenz zur Mischbarkeit auf. Anhand der DSC–Untersuchungen wurde hier vorübergehend eine Misch-Tg gefunden. Nur bei der Probe mit symmetrischer Zusammensetzung wurden zwei getrennte Tg beobachtet. Die Streukurven von diesem System waren sehr schwach ausgeprägt. Dadurch die Indizierung der vorhandenen Morphologien war nicht eindeutlich. Der berechnete Wechselwirkungsparameter beträgt 0,022. Bei den AFM-Untersuchungen zum Entmischungsverhalten in dünnen PPrMA-b-PMMA Filmen wurden entweder keine oder sehr schwach geordnete Nanostruktur gefunden. Im Gegensatz zu dem vorherigen System, die Benetzbarkeit der PPrMA-b-PMMA Filme war durch die Zusammensetzung der Diblockcopolymere bedingt.

L’objectif de cette thèse est d’étudier la synthèse et les propriétés d’auto-assemblage en milieu aqueux de copolymères « intelligents » capables de former des agrégats supramoléculaires en réponse à deux stimuli : la température du milieu et la présence de dioxyde de carbone (CO2). Pour cela, une gamme de copolymères diblocs amphiphiles composés d’un bloc hydrophile d’acrylate de polyethylèneglycol méthyléther) (PEGA) et d’un bloc stimulable contenant une distribution statistique d’unités PEGA et acrylate de diéthlèneglycol éthyléther (DEGA) (thermosensibles) et acrylate de diéthylaminoéthyle DEAEA (CO2-sensible), a été préparée par polymérisation radicalaire contrôlée par les nitroxydes (NMP). Dans un second temps, il a été mis en évidence que la température ainsi que la présence de CO2 dans la solution influencent le comportement auto-associatif des copolymères dans l’eau. Par la suite, le bloc hydrophile a été remplacé par une séquence de dextrane, ce qui a permis de préparer de nouveaux copolymères diblocs fonctionnels, stimulables par la température et le CO2. Dans ce cas, deux techniques de polymérisation radicalaire contrôlée (NMP et ATRP) ont été testées afin d’obtenir les copolymères possédant l’architecture la mieux définie possible. / This project aims to investigate the synthesis and properties of dual stimuli-responsive block copolymers able to self-assemble into supramolecular aggregates in response to two stimuli: the temperature and the presence of carbon dioxide in the aqueous solution. Therefore, a range of amphiphilic diblock copolymers composed of a hydrophilic block of polyethylene glycol methylether acrylate (PEGA) and a statistical block of PEGA, diethylene glycol ethyl ether acrylate (DEGA) and diethylaminoethyl acrylate (DEAEA) was prepared via nitroxide-mediated polymerization (NMP) and the level of control of each synthesis was studied. We evidenced that temperature and CO2 play a different role in the self-assembly of such block copolymers. Finally, the introduction of dextrane as hydrophilic block coming from renewable resources allows for the preparation of novel “smart” amphiphilic diblock copolymers. In order to synthesize these block copolymers with well-defined structure, both NMP and atom transfer radical polymerization (ATRP) were investigated in parallel.