Doctor of Philosophy / Department of Chemistry / Takashi Ito / We have investigated the orientation of cylindrical domains in thin films of a polystyrene–poly(methylmethacrylate) diblock copolymer (PS-b-PMMA) on planar substrates having different surface roughnesses and hydrophilicities. The research in this dissertation covers the substrate surface modifications, the enhancement of the diblock copolymer film coating, and the refinement of the treatments leading to nanoporous material. Treatment of the substrate with organic mercaptans forming self-assembled-monolayer (SAM), leading to various hydrophilicities of the surfaces, was inconclusive as far as orienting the PMMA domains in the PS matrix due to thermal instability of some thiols. This directed us to a different approach involving substrate roughness. PS-b-PMMA films of 20~200 nm thick were prepared via spin-coating on silicon, gold or indium tin oxide (ITO) substrates, and annealed in vacuum at 170 °C for 60 hours to induce the formation of cylindrical PMMA domains. Atomic force microscopy (AFM) images indicated the domain orientation at the free surface. In PS-b-PMMA films much thicker than the domain periodicity (L0), the domains were oriented perpendicularly to the free surface regardless of underlying substrates, reflecting the balanced interactions of PS and PMMA blocks at the polymer–vacuum interface. In films having thickness similar to L0, vertically oriented domains were observed on the Au and ITO surfaces that are covered with nanoscale grains, whereas horizontal domains were observed on the smooth Si substrates. In particular, the cylindrical PMMA domains were efficiently perpendicularly aligned when the grain size nearly was equal to L0. The perpendicular domain alignment induced by the substrate roughness was corroborated using cyclic voltammetry (CV) for gold substrates coated with PS-b-PMMA films whose PMMA domains were removed by UV and subsequent acetic acid treatments. The CV data also suggested that the PMMA domains were successfully removed, leaving a nanoporous stable PS matrix on the substrate.

A molecular dynamics coarse-grained block copolymer (BCP) model was developed and used to studied directed self-assembly (DSA), especially in regards to applications for semiconductor manufacturing. Most of the thesis is spent investigating the effect that guiding layer properties and block copolymer properties have on line roughness and defect density in a BCP-DSA process. These two effects are perhaps the most critical in making BCP-DSA a cost efficient industrial process. It is found that guiding patterns have little effect on line roughness and in fact that the BCP heals the majority of roughness in the underlying pattern. BCP properties have a larger effect on line roughness. Segregation strength (as measured by χN, where χ is the Flory- Huggins interaction parameter and N is the degree of polymerization) resulted in a larger than expected increase in line roughness when χN was low. Polydispersity resulted in a moderate increase in line roughness. In regards to equilibrium defect density, free energy calculations showed that χ was the primary determining factor, not χN as many expected. Equilibrium defect density was found to decrease exponentially with increasing χ. Defect density is also found to scale exponentially with polydispersity. Concerning defect heal rate, which can increase the real defect rate of a process if said rate is too low, it is found that increasing χN linearly increased the barrier to defect healing, which means that the defect heal rate decreases exponentially. However, for thin films this is only true for χN > ~ 50. Below χN ~ 50, the barrier is approximately constant. These results give excellent guidance to the type of materials and processes necessary to optimize a BCP-DSA process. A simulation technique designed to more efficiently sample over energy barriers called protracted noise dynamics for polymer systems was developed and studied. It was found that a decrease in simulation time of up to 4 orders of magnitude was achieved. The effect of box size on allowable pitches for a lamellar forming BCP was derived and demonstrated. It was found that more elongated boxes yielded more possible pitches and more accurate results. A short study on the effect of multiblock copolymers on the location of the order-disorder transition was also carried out and it was found that multiblock copolymers had small effect on the ODT. The distribution of chain conformations was also calculated.

Betulin is a naturally abundant compound in the outer bark of birch and can be easily obtained by solvent extraction. Herein, solutions of betulin were used to treat cellulosic textile fibers and improve their water repellency. Cotton fabrics impregnated in a 7.5 g L-1 solution of betulin in ethanol showed the highest water contact angle of about 153° while the impregnation in a 3.75 g L-1 solution resulted in a close effect. A terephthaloyl chloride-betulin copolymer was synthesized and dissolved in tetrahydrofuran to afford a solution with a concentration of 3.75 g L-1. The cotton fabric impregnated in this solution showed a water contact angle of 150°. Changes in morphology of the cellulose fibers before and after the treatment were observed by scanning electron microscopy, and the water repellency was measured by a standard spray test. The marketing strategy of the potential product, which will be developed based on this technique, was discussed.

Crosslinkable and pH-sensitive amphiphilic block copolymers are promising candidates to establish pH-stable and permeable vesicles for synthetic biology. Here, we report the fabrication of crosslinked and pH-stable polymersomes as swellable vesicles for the pH-dependent loading and release of small dye molecules. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Plasmid DNA (pVAX1-NH36) was encapsulated in nanoparticles of poly-dL-lactic-coglycolic ( PLGA) functionalized with polyethylene glycol ( PEG) and folic acid (PLGA-PEG-FA) without losing integrity. PLGA-PEG-FA nanoparticles loaded with pVAX1-NH36 (pDNA-NPs) were prepared by using a double emulsification-solvent evaporation technique. PLGA-PEG-FA synthesis was verified by FT-IR and spectrophotometry methods. pVAX1-NH36 was replicated in Escherichia coli (E. coli) cell cultures. Atomic force microscopy (AFM) analysis confirmed pDNA-NPs size with an average diameter of 177-229 nm, depending on pVAX1-NH36 loading and zeta potentials were below 24 mV for all preparations. In vitro release studies confirmed a multiphase release profile for the duration of more than 30-days. Plasmid release kinetics were analyzed with a release model that considered simultaneous contributions of initial burst and degradation-relaxation of nanoparticles. Fitting of release model against experimental data presented excellent correlation. This mathematical analysis presents a novel approach to describe and predict the release of plasmid DNA from biodegradable nanoparticles.

Molecular weights of 2,000, 6,000 and 10,000 of silane functionalized atactic polystyrene (aPS) and α,ω-divinyl functionalized polydimethylsiloxane (PDMS) were prepared via living anionic polymerization and bulk anionic ring opening polymerization respectively. Functionalization of the homopolymers was confirmed by FT-IR and 1H-NMR spectroscopy and their molecular weights were determined via 1H-NMR end group analysis. A hydrosilylation reaction between the functionalized homopolymers of different molecular weights produced nine polystyrene-block-polydimethylsiloxane-block-polystyrene (aPS-b-PDMS-b-aPS) triblock copolymers. Field emission scanning electron microscopy observations revealed the copolymers self-assemble into supramolecular structures. Dynamic Light Scattering measurements show only small increase in the order of nanometers of its hydrodynamic radius as the individual molecular weights of the homopolymers were increased. Nanocomposites of the copolymers were prepared by incorporating 1% of oxidized single walled carbon nanotubes (SWNTs) within the aPS-PDMS-aPS matrices via coagulation precipitation. Differential scanning calorimetry (DSC) thermal analysis shows the SWNT interacting with both aPS and PDMS constituting blocks. SWNTs interaction with aPS block either increases the polymer glass transition temperature (Tg) by restricting its segmental motion or decreases the Tg by a plasticization effect. Within the PDMS block the SWNTs act as nucleating sites accelerating the crystallization rate of the polymer. This is evident by the appearance of single and double melting endotherms in the DSC thermograms.

La nanochimie et l’auto-assemblage sont des voies prometteuses de fabrication de matériaux nanostructurés aux propriétés optiques innovantes dans le domaine visible. Dans cette étude, des nanocomposites plasmoniques anisotropes sont formulés en introduisant sélectivement des nanoparticules métalliques dans des phases ordonnées de copolymères diblocs symétriques selon différentes stratégies d’incorporation. Pour la stratégie de post-incorporation, des nanoparticules d’or présynthétisées en milieu aqueux sont introduites sélectivement dans des phases pré-ordonnées d’un copolymère dibloc amphiphile. L’incorporation directe consiste àmélanger des nanoparticules d’or présynthétisées et un copolymère dibloc dans un solvant commun.La synthèse in situ de nanoparticules consiste à réduire des précurseurs métalliques préalablement introduits dans un des deux blocs d’un copolymère via une étape de réduction. Nous étudions, en particulier, comment la taille des nanoparticules d’or et leur fraction volumique influencent la nanostructure et les propriétés optiques de ces films nanocomposites. La morphologie des films macroscopiques est étudiée par microscopie électronique à transmission et diffusion des rayons Xaux petits angles. Les films minces de nanocomposites sont caractérisés structurellement parmicroscopie à force atomique, microscopie électronique à transmission et réflectivité des rayons X. Les indices optiques déterminés par ellipsométrie spectroscopique peuvent être décrits par un modèle de Maxwell-Garnett, prenant éventuellement en compte de façon phénoménologique les effets de couplage entre nanoparticules d’or. / Nanochemistry and self-assembly are promising ways to fabricate nanostructuredmaterials with innovative optical properties for visible light. In this work, anisotropic plasmonicnanocomposites are formulated by selectively introducing metallic nanoparticles in ordered phasesof symmetric dibloc copolymers with different strategies. For the strategy of post-incorporation, presynthesizedgold nanoparticles in aqueous medium are selectively introduced in pre-ordered phasesof an amphiphilic dibloc copolymer. Direct incorporation consists in mixing pre-synthesized goldnanoparticles and dibloc copolymer in a common solvent. In situ synthesis of nanoparticles consistsin reducing metallic precursors previously introduced in one of two blocks of a copolymer via areduction step. The influence of the size and the volume fraction of gold nanoparticles on thenanostructure and the optical properties of the nanocomposite films have been particularly studied.Morphology of macroscopic films is studied by transmission electron microscopy and small angle Xrayscattering. The nanocomposite thin films are structurally characterized by force atomicmicroscopy, transmission electron microscopy and X-ray reflectivity. The optical indices obtained byspectroscopic ellipsometry can be described with Maxwell-Garnett models, which can take intoaccount phenomenologically the effects of coupling between gold nanoparticles.

A une époque où les technologies nouvelles fleurissent chaque jour, un domaine particulier se détache : l’électronique organique. Par son utilité et sa facilité de mise en œuvre, l’électronique organique affiche de grandes promesses pour l’avenir. Dans le but d’améliorer le procédé de fabrication et la durée de vie de ces dispositifs, le travail de cette thèse s'est focalisé sur la synthèse de copolymères à architectures variées à base de poly(3-hexylthiophène) (P3HT). Après avoir exposé les problématiques et objectifs de la thèse dans une première partie, la synthèse de différents précurseurs P3HT est décrite. Ces matériaux représentent la base des travaux présentés dans cet ouvrage. Dans un premier temps, l'optimisation de la synthèse des copolymères à blocs rigide-flexible a été réalisée en suivant une stratégie adaptée pour une application en électronique organique. La conception de nouveaux matériaux semi-conducteurs à architectures ramifiées est traitée par la suite. Enfin, le dernier chapitre porte sur l'intégration d’un copolymère, le P3HT-b-Poly(4vinylpyridine), en cellule photovoltaïque organique en tant qu'additif de la couche active. Cette approche s’avère être particulièrement puissante, permettant notamment de diminuer le temps et le coût énergétique de la mise en œuvre de ces cellules en s’affranchissant d’une étape clé de la fabrication, le recuit. / At a time when new technologies emerge every day, a specific domain stands out: the organic electronic. Through its low cost processing or even its utility, the organic electronic constitutes a very promising future.In order to improve the fabrication process and the lifetime of the devices, the work of this thesis was focused on the synthesis of copolymers with various architectures based on poly(3-hexylthiophene) (P3HT). After a first part where main issues and objectives are presented, the synthesis of different P3HT-based precursors is described in a part which could be considered as the heart of these works. Starting with appropriated precursors, the optimization of rod-coil diblock copolymer synthesis was performed following a strategy designed specifically for organic electronic application. Moreover, the precursors were used for the conception of new semi-conducting materials with a variety of architectures, such as graft and star copolymers. Finally, the last part deals with the integration of the P3HT-b-Poly(4-vinylpyridine) copolymer into organic solar cell as an additive of the active layer. This approach turns out to be powerful, especially allowing decreasing the time and the energy cost by avoiding the key step of the fabrication process of those devices, the annealing step.

O fascínio e a curiosidade da humanidade pela luz incentivaram a compreensão dos fenômenos que envolvem a interação matéria-energia, levando a um avanço tecnológico jamais visto antes. Com essa compreensão, atualmente é possível criar materiais com inúmeras finalidades; como na extensa área de micro e optoeletrônica; como na confecção de OLEDs e OPVs; no desenvolvimento de revestimentos inteligentes; marcadores biológicos; materiais para drug delivery; entre muitas outras aplicações. Seguindo essa perspectiva, a classe dos corantes rilênicos conhecida por naftalimidas possuem propriedades únicas que permitem a confecção dos mais diversos materiais. Desta maneira, o presente estudo sintetizou dois monômeros naftálicos inéditos derivados da 1,8-naftalimida e da 1,4,5,8-naftalenodiimida, os monômeros NI-AL e NDI-ALp. Além disso, também foram sintetizados dois copolímeros compostos por estireno-co-NI-AL e estireno-co-NDI-ALp. Para cada copolímero houve a variação da proporção estireno/comonômero, gerando, ao todo, dez copolímeros (seis de estireno-co-NI-AL e quatro de estireno-co-NDI-ALp). Os copolímeros foram analisados através de técnicas espectrométricas (1H RMN, FTIR, UV-Vis, Fluorescência, Reflectância) e cromatográficas (GPC). Os resultados indicaram que o copolímero de estireno-co-NI-AL sofre agregação devido às interações π-π, mas não há transferência de cargas entre os comonômeros. Já o copolímero estireno-co-NDI-ALp forma uma complexação no estado fundamental, deslocando a fluorescência da NDI-ALp para a região do verde e causando o surgimento de uma banda a 450 nm no espectro de UV-Vis. / The fascination and curiosity of humanity for light has stimulated the understanding of the interaction between energy and matter, leading to a technological advance never seen before. It is now possible to create materials with numerous purposes such as the extensive area of micro and optoelectronics, the manufacturing of OLEDs and OPVs, the development of intelligent coatings, biological markers, materials for drug delivery, among many others applications. Following this perspective, a class of rylene dyes known as naphthalimides have unique properties that allow the synthesis of numerous materials. In this study, two novel naphthalene allyl monomers derived from 1,8-naphthalimide and 1,4,5,8-naphthalenediimide have been synthesized, the monomers NI-AL and NDI-ALp. In addition, copolymers of styrene-co-NI-AL and styrene-co-NDI-ALp presenting different compositions were also synthesized. For each copolymer, the styrene: comonomer ratio varied, generating altogether tem copolymers (six of styrene-co-NI-AL and four of styrene-co-NDI-ALp). The copolymers were analyzed by spectrometric (1H NMR, FTIR, UV-Vis, Fluorescence) and chromatographic (GPC) techniques. The results indicated that the styrene-co-NIAL copolymer undergoes aggregation due to the π-π interactions, but there is no charge transfer between the comonomers. However, the styrene-co-NDI-ALp copolymer forms a complexation in the ground state, displacing the NDI-ALp fluorescence to the green region and causing the appearance of a band at 450 nm in the UV-Vis spectrum attributed to charge transfer complexes.

Les polymères présentant des liens phosphoesters dans leur squelette sont biodégradables et constituent une classe émergente de nouveaux biomatériaux, utiles notamment dans le domaine de la délivrance de médicaments. La pentavalence du phosphore offre de nombreuses possibilités d’en varier la structure ce qui permet d’envisager une gamme diversifiée de propriétés pour ces matériaux.Cette thèse envisage la synthèse et l’utilisation de nouveaux copolymères biséquencés de polyoxyde d’éthylène et de polyphosphotriester portant des insaturations pendantes comme plateforme pour l’élaboration de systèmes de délivrance avancés. D’une part, l’auto-assemblage en milieu aqueux de copolymères amphiphiles porteurs de groupes butènyles permet l’obtention de micelles à coeur réticulé dans lesquelles la doxorubicine peut être incorporée par imprégnation. Ces nanovecteurs micellaires montrent une stabilité et un taux d’encapsulation supérieurs aux systèmes non réticulés correspondants.D’autre part, des copolymères porteurs de groupes alcynyl ou allyl pendants sont convertis en copolymères doublement hydrophiles capables de complexer le calcium. Utilisés comme agent structurant pour la formation de particules de carbonate de calcium, ceux-ci permettent d’en réduire la taille et son hétérogénéité de façon remarquable. Le recours à un procédé utilisant le dioxyde de carbone à l’état supercritique conduit ainsi à des particules de 1.5μm.Enfin, l’ajout de lysozyme à ce procédé permet son encapsulation dans les particules de CaCO3, en préservant l’activité de cette protéine plus efficacement que le procédé conventionnel recourant à l’acide hyaluronique. / Polymers with repeating phosphoester linkages in the backbone are biodegradable and emerged as a promising class of novel biomaterials, especially in the field of drug delivery systems. The pentavalency of the phosphorus atom offers a large diversity of structures and as a consequence a wide range of properties for these materials.The thesis focused on the synthesis of novel well-defined diblock copolymers made of one hydrophilic polyethylene oxide (PEO) block and one polyphosphotriester (PPE) block bearing unsaturations as side-group, as a platform for the design of advanced drug delivery systems.Firstly, novel alkenyl PEO-b-PPE amphiphilic copolymers were self-assembled in water, taking profit of the unsaturations to prepare core cross-linked micelles. Doxorubicin could be successfully loaded by impregnation in these micellar nanocarriers leading to improved stability and loading as compared to the corresponding non-cross-linked systems.Besides, the alkynyl and allyl unsaturations of PEO-b-PPE copolymers were used to prepare novel double hydrophilic block copolymers exhibiting calcium complexation capabilities. They were found quite efficient as template for the formation of calcium carbonate particles providing particles of unprecedented small size, and high size homogeneity. The use of a supercritical carbon dioxide process with carboxylic acid containing copolymers allows reaching CaCO3 particles about 1.5 μm. Finally, we demonstrate that adding lysozyme to the process allows encapsulation of this enzyme into the CaCO3 carriers, the protein activity being better preserved by using the PPE-b-PEO as compared to more conventional hyaluronic acid as a template.