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Hybrid Materials of Block Copolymers and Magnetic NanoparticlesZHOU, ZHIHAN 10 September 2010 (has links)
In this PhD thesis, the preparation of several types of hybrid materials of block copolymer and magnetic nanoparticles is described. The diversified morphologies of nanoaggregates formed by dispersing poly(glyceryl methacrylate)-block-poly(2-cinnamoyloxyethyl methacrylate)-block-poly(tert-butyl acrylate) tri-block copolymers in block selective solvents will be reported first. The volume occupied by the core block in these nanoaggregates can be swollen by solvent, and the core block can be sculpted. The cores can act potentially as the template to grow magnetic nanoparticles. Thus, a potential method for preparing hybrid magnetic materials of block copolymers and magnetic nanoparticles with different morphologies is developed.
A one-pot method to synthesize cobalt nanoparticles covered by a polymer shell is then reported. This is achieved by thermally decomposing dicobalt octacarbonyl in the presence of polymeric multi-dentate ligand poly(ethylene glycol)-block-poly(acrylic acid). Using a similar method, cobalt nanoparticles covered by poly(2-cinnamoyloxyethyl methacryate)-block-poly(acrylic acid) ligand are synthesized. The cobalt nanoparticles fuse into chains for their magnetic dipole-dipole interaction. The chains are then coated with poly(tert-butyl acrylate)-block-poly(2-cinnamoyloxyethyl methacrylate). The coated Co chains are further locked by photo-crosslinking the poly(2-cinnamoyloxyethyl methacrylate) segments. The as-prepared cobalt nano wires have interesting magnetic response and may be used to build complicated magnetic nano devices.
Another hybrid magnetic material is prepared via an oil-in-water emulsion method. The oil phase of the emulsion sphere consists of r-Fe2O3 magnetic nanoparticles covered with the poly(2-cinnamoyloxyethyl methacryate)-block-poly(acrylic acid) ligand and a poly(2-cinnamoyloxyethyl methacryate) homopolymer. It was dispersed in water using a mixture of poly(2-cinnamoyloxyethyl methacrylate)-block-poly(succinoylglyceryl methacrylate) and poly(2-cinnamoyloxyethyl methacrylate)-block-poly(glyceryl methacrylate) as the surfactants. The evaporation of the organic solvent left behind solid particles in water. The polymer chains on the surface of the obtained spheres allow the immobilization of biomolecules. Factors affecting the emulsion process are studied systematically. The emulsion spheres are characterized using TEM, AFM, TGA and etc. The emulsion sphere have potential application is immunoassay. The protein binding capacity of the spheres is determined. / Thesis (Ph.D, Chemistry) -- Queen's University, 2010-09-10 11:50:46.618
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Development of block copolymer based nanocarriers for the solubilization and delivery of valspodarBinkhathlan, Ziyad Unknown Date
No description available.
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Understanding Elastin-Like Polypeptide Block Copolymer Self-assembly BehaviorHassouneh, Wafa Saadat January 2013 (has links)
<p>Elastin-like polypeptides (ELPs) are thermally responsive polymers composed of the pentapeptide repeat Valine-Proline-Glycine-X-Glycine where X is any amino acid except proline. ELP diblocks have been engineered by creating two ELP blocks with hydrophilic and hydrophobic guest residues. The hydrophobic block desolvates at a lower temperature and forms the core of a micelle while the still hydrated hydrophilic block forms the corona. ELP micelles are promising drug delivery vehicles for cancer therapeutics. ELP diblocks offer a unique method to display targeting proteins multivalently on micelles to improve tumor cell uptake. As ELPs are genetically encoded, proteins can be seamlessly fused at the genetic level to the ELP diblock. The protein ELP diblock fusions can be synthesized as one polypeptide chain that is of precise molecular weight and highly monodisperse, and no post-synthesis modification is necessary. Self-assembly behavior of ELP diblocks is known to tolerate fusion to small peptides (< 10 amino acids) but their self-assembly behavior has not be examined when fused to proteins that are 100-200 amino acids. Here, we hypothesize that molecular weight of the protein and the surface properties of the protein will be factors in determining its effect on ELP diblock self-assembly. In addition, the ELP block lengths and composition are hypothesized to be factors in the self-assembly behavior of protein ELP diblock fusions. This hypothesis is tested by fusing four proteins with different properties to various ELP diblocks and characterizing their self-assembly behavior. The proteins were found to dominate the self-assembly behavior. Proteins that disrupted self-assembly did so for all ELP diblock lengths and compositions. Protein that did not disrupt self-assembly behavior affected the thermal behavior of the hydrophilic block. Hydrophilic proteins increased the micelle-to-aggregate transition temperature while hydrophobic proteins decreased it. We also sought to understand the self-assembly of ELP diblocks on a theoretical basis. A previously developed model for the self-assembly of synthetic polymers was applied to our polypeptide system. Two parameters, solvent quality of the corona and surface tension of the hydrophobic block, were experimentally measured and used to fit the model. Predictions of micelle radius and aggregation numbers were in good agreement with experimental data. However, the corona was found to be unstretched compared to its Gaussian size by this model. Therefore, a new model was developed describing what is termed as weak micelles in which the corona is not stretched but rather close to Gaussian size. The weak micelle model prediction were also in good agreement with experimental data suggesting that ELP micelles are in the crossover regime between the previous model and the new model.</p> / Dissertation
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Development of methoxy poly(ethylene glycol)-block-poly(caprolactone) amphiphilic diblock copolymer nanoparticulate formulations for the delivery of paclitaxelLetchford, Kevin John 11 1900 (has links)
The goal of this project was to develop a non-toxic amphiphilic diblock copolymer nanoparticulate drug delivery system that will solubilize paclitaxel (PTX) and retain the drug in plasma. Methoxy poly(ethylene glycol)-block-poly(ε-caprolactone) (MePEG-b-PCL) diblock copolymers loaded with PTX were characterized and their physicochemical properties were correlated with their performance as nanoparticulate drug delivery systems. A series of MePEG-b-PCL was synthesized with PCL blocks ranging from 2-104 repeat units and MePEG blocks of 17, 44 or 114 repeat units. All copolymers were water soluble and formed micelles except MePEG₁₁₄-b-PCL₁₀₄, which was water insoluble and formed nanospheres.
Investigation of the effects of block length on the physicochemical properties of the nanoparticles was used to select appropriate copolymers for development as PTX nanoparticles. The critical micelle concentration, pyrene partition coefficient and diameter of nanoparticles were found to be dependent on the PCL block length. Copolymers based on a MePEG molecular weight of 750 g/mol were found to have temperature dependent phase behavior.
Relationships between the concentration of micellized drug and the compatibility between the drug and core-forming block, as determined by the Flory-Huggins interaction parameter, and PCL block length were developed. Increases in the compatibility between PCL and the drug, as well as longer PCL block lengths resulted in increased drug solubilization.
The physicochemical properties and drug delivery performance characteristics of MePEG₁₁₄-b-PCL₁₉ micelles and MePEG₁₁₄-b-PCL₁₀₄ nanospheres were compared. Nanospheres were larger, had a more viscous core, solubilized more PTX and released it slower, compared to micelles. No difference was seen in the hemocompatibility of the nanoparticles as assessed by plasma coagulation time and erythrocyte hemolysis. Micellar PTX had an in vitro plasma distribution similar to free drug. The majority of micellar PTX associated with the lipoprotein deficient plasma fraction (LPDP). In contrast, nanospheres were capable of retaining more of the encapsulated drug with significantly less PTX partitioning into the LPDP fraction.
In conclusion, although both micelles and nanospheres were capable of solubilizing PTX and were hemocompatible, PTX nanospheres may offer the advantage of prolonged blood circulation, based on the in vitro plasma distribution data, which showed that nanospheres retained PTX more effectively.
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Vers l'industrialisation de l'auto-assemblage dirigé des copolymères à blocs : développement de procédés de lithographie compatibles avec les noeuds technologiques sub-10 nm pour des applications de type contacts / Towards the industrialization of directed self-assembly of block copolymers : development of lithographic processes compatible with sub-10 nm technology nodes for contact applicationsBouanani, Shayma 06 October 2017 (has links)
La course à la compétitivité que se disputent les industriels du semi-conducteur implique d’augmenter le nombre de fonctionnalités par puce ainsi que de réduire leur coût unitaire, ce qui se traduit par une diminution continue de leur taille. Pour ce faire, le DSA (Directed Self-Assembly), ou auto-assemblage dirigé des copolymères à blocs associe les techniques de lithographie conventionnelle avec les propriétés d’organisation à l’échelle moléculaire des copolymères. Dans ce cadre, l’objectif global de cette thèse est d’évaluer le potentiel d’industrialisation du DSA par grapho-épitaxie pour des applications de type « shrink » et « multiplication » de contacts. Il s’agit en particulier de démontrer la capacité de cette technique à répondre au cahier des charges de l’ITRS en termes d’uniformité de CD, de désalignement et de taux de défauts. Une première étude concernant le « shrink de contact », basée sur l’impact des propriétés matériaux, d’affinité de surface et de tailles de guides permet de comprendre les mécanismes qui rentrent en jeu dans l’apparition de défauts d’assemblage. Une seconde partie de l’étude porte sur la multiplication de contact. Pour adresser cette application, deux types de guides ont été étudié : les guides elliptiques et les guides complexes dits « peanut ». L’étude de la fenêtre de procédé en termes de paramètres procédé comme le temps et la température de recuit, mais aussi de commensurabilité, a été menée. Une attention particulière a été portée sur l’impact de la variation du guide sur le pitch final obtenu en DSA, dont les données expérimentales ont été corrélées avec des résultats de simulation. Les critères de réussite sont basés sur les performances lithographiques qu’il faut juger à travers une métrologie de pointe. Le développement d’une métrologie spécifique pour mesurer l’erreur de placement des contacts ainsi que leur pitch a été conduite. / The competitiveness-chasing in which industrial manufactures are involved, leads to an exponential increase in the number of functionalities per chips, as well as reducing their unit cost, which results in a continuous decrease of their size. To achieve this, DSA (Directed Self-Assembly) of block copolymers, combines conventional lithography techniques with the molecular-scale organizational properties of copolymers. In this framework, the overall objective of this thesis is to evaluate the industrialization potential of the DSA process by graphoepitaxy for contact hole shrink and contact multiplication applications. In particular, it is necessary to demonstrate the ability of this technique to meet the ITRS specifications in terms of CD uniformity, misalignment and hole open yield. A first study on contact shrink, based on the impact of material properties, surface affinity and guiding feature size, allows us to understand the mechanisms involved in the appearance of defects. A second part of the study deals with contact multiplication. To address this application, two types of guides have been studied: elliptical guiding patterns and more complex ones called "peanut". The study of the process window in terms of process parameters such as annealing time and temperature, but also commensurability was conducted. Particular attention was paid to guide size variation and its impact on DSA final pitch. Experimental data from this study were correlated with simulations. The success criteria are based on the lithographic performances that must be judged through advanced metrology. The development of a specific metrology to measure the placement error of contacts as well as their pitch was conducted.
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Etude d’une lithographie ligne/espace innovante par auto-assemblage dirigé d’un copolymère à blocs pour la réalisation de dispositifs CMOS sub-20nm / Study of an innovative line/space directed self-assembly lithography of block copolymers for the conception of sub 20nm CMOS devicesClaveau, Guillaume 14 December 2017 (has links)
Dans le contexte d’une miniaturisation des circuits imprimés dans l’industrie de la microélectronique, les méthodes de structuration optiques appelées photolithographies arrivent en limite de résolution. L’utilisation complémentaire de l’auto-assemblage dirigé (DSA) de copolymère à blocs (CPB) permet de repousser les dimensions critiques (CD) atteignables tout en multipliant la densité des structures obtenues. Ces matériaux peuvent en effet former des motifs géométriques biphasés et périodiques de dimensions inférieures à la vingtaine de nanomètre. Rapides, bas coût et compatibles avec les équipements déjà disponibles dans l’industrie, les différents procédés DSA pour application ligne/espace développés dans la littérature se heurtent néanmoins à des problématiques de défectivité, de rugosité et d’uniformité des dimensions transférées. La plupart des solutions envisagées se font au détriment des arguments de base en faveur du DSA, notamment en ce qui concerne sa compatibilité avec la lithographie actuellement utilisée dans l’industrie. Dans ce contexte, le travail de thèse présenté ici s’attachera à étudier et solutionner les différentes problématiques liées à l’utilisation en graphoépitaxie du DSA comme solution complémentaire à la lithographie conventionnelle. Cette thèse centrée sur le matériau PS-b-PMMA s’est tout d’abord attachée à la compréhension des mécanismes impliqués dans la structuration de ces domaines lamellaires dans deux environnements. En configuration plane tout d’abord, l’impact des paramètres dictant la morphologie, l’orientation et la défectivité du CPB est étudié. La cinétique d’organisation des micro domaines peut alors être optimisée pour obtenir des motifs les mieux définis et les plus stables possibles, en un minimum de temps. Des optimisations matériaux proposées par la société partenaire ARKEMA sont évaluées comme prometteuses, et l’importance du contrôle de l’atmosphère sur le comportement du CPB en température est étudiée. En utilisant ces premiers acquis, le matériau est utilisé pour réaliser la densification de motifs « guides » ligne/espace préalablement réalisés par lithographie optique. L’étude de la morphologie adoptée par le polymère en fonction des multiples paramètres du guide (dimension, chimie d’interface, taux de remplissage…) permet de délimiter des fenêtres de fonctionnement pour un procédé stable sur plaque 300mm. La dimension de ces fenêtres est confirmée par une étude statistique suivant les métriques de défectivité et de rugosité, mesurées par un protocole de métrologie développé pendant cette thèse. Cette première étude a fait l’objet d’une publication d’un papier. Dans un effort de démonstration de l’intérêt de ce procédé, son intégration dans un empilement de réalisation de transistors en nanofils est réalisée. De premiers essais de transfert révèlent des problématiques de défectivités locales jusqu’alors masquées par l’épaisseur du film. Les méthodes de transferts disponibles étant incapables de corriger ces défauts, une variante du procédé DSA est développée. Elle repose sur la possibilité de modifier sélectivement les énergies de surfaces par application d’une dose contrôlée de lumière UV. Une étude associant à la fois la modification de la morphologie du PS-b-PMMA et la composition du matériau (suivie par spectroscopie infrarouge) en fonction de cette dose d’insolation révèle qu’un phénomène de photo-oxydation est responsable de ces phénomènes. Grâce à cette méthode, qui fait l’objet d’une publication en cours de soumission, les surfaces directement en contact avec le CPB sont modifiées de façon à le contraindre à adopter des configurations morphologiques sans défauts enterrés. Ce résultat est confirmé par les différentes étapes de transfert qui permettent de réaliser les nanofils désirés avec des dimensions maîtrisées. Des problématiques d’uniformité de remplissage sont toutefois adressées car elles restent un obstacle des nanofils uniformes à travers une plaque 300mm. / There is a fixed limit to the maximum resolution the photolithography can provide in the context of the integrated circuit’s size reduction encouraged by the microelectronic industry. The Directed Self-Assembly (DSA) of bloc copolymers (BCP) can be used as a complementary technique enabling smaller critical dimensions of features (CD) obtained by density multiplication of initial, loose i193 lithography patterns. These materials can undergo specific phase separation to self-assemble into periodic, sub-20nm ordered nanostructures.Fast, cost-efficient and highly compatible with equipment and techniques already in use in the industry for line/space (L/S) applications, the different DSA processes found in literature still suffer from defectivity, roughness and CD uniformity (CDU) issues. Most successful solutions are made possible at the loss of some of the most appealing DSA features, mainly its compatibility with current i193 lithography. In this context, the work of this thesis studied and proposed innovative solutions to the problematics posed when using graphoepitaxy as the DSA complementary technique.This work presented therein - revolving around a 38nm period lamellar PS-b-PMMA material - first tried to comprehend the mechanisms involved in the self-assembly of lamellae in one of two environment: flat configuration and 3D, graphoepitaxy configuration. In the former, a study of the parameters dictating the morphology, orientation and defect levels of the BCP was performed. This provides a mean to optimize the kinetics of self-assembly to last less than five minutes while enabling stable and reproducible morphology. Materials optimization and atmosphere composition’s impact during annealing is also discussed. This initial knowledge is then used to perform the density multiplication of L/S guiding pattern using conventional optical lithography at Leti. The study of the lamellae morphology as a function of the multiples guiding patterns’ parameters (CD, interface chemistries, thickness levels…) provides fixed process windows (PW) for a stable process over a 300mm wafer. The shape and size of these PWs is further confirmed by a statistic study of defectivity and roughness metrics as defined by a specific metrology protocol developed during this thesis. This work has led to the publication of a paper.In an effort to demonstrate its relevance in the industry, full integration of this DSA process is carried out in pursuit of functional stacked nanowire (NW) transistors acquisition. First etching tests failed though, as they revealed unknown defective formation of the lamellae at the buried interface. The etching process Leti available at Leti proved enable to compensate for these local variations of transfer features. Consequently, a new iteration of the DSA process is presented. It consists in using UV light exposure to selectively shift the interfacial energies of the guiding patterns’ surfaces. A study of the shift in both the observed lamellae morphology and the composition of the material (followed by Infrared Spectroscopy) as a function of the UV dosage is performed. It identifies a photo-oxidation mechanism which can be finely tuned to independently promote defect-free alignment of the BCP lamellae with any of the guiding pattern surfaces. This work, currently awaiting publication, is further verified by the different etching steps achieving monocrystalline silicon nanowires of controlled dimensions. The associated transistors are now being submitted to electrical characterization. Full wafer uniformity of features is a work in progress however, as BCP thickness filling of guiding patterns is still highly dependent on their density.
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Films nanocomposites plasmoniques auto-assemblés / Self-Assembled Plasmonic Nanocomposite FilmsAubrit, Florian 15 November 2017 (has links)
Les métamatériaux sont des matériaux artificiels, formés par l’assemblage de nano-résonateurs, qui ont la capacité d’interagir avec les ondes qui les traversent et de conférer des propriétés inaccessibles aux matériaux homogènes. Afin de fabriquer de tels métamatériaux agissant dans le domaine du visible, un contrôle précis de l’organisation des résonateurs à l’échelle nanométrique est requis. Dans ce projet nous avons donc élaboré des voies de fabrication de type bottom-up, en organisant de façon anisotrope des nanoparticules d’or (AuNPs), qui sont des résonateurs du fait de leurs propriétés plasmoniques, dans un film de copolymères à blocs poly(styrène)-b-poly(vinylpyridine) (PS-b-PVP) nano-structuré en rangées de cylindres de PVP perpendiculaires au substrat.Au cours de ce projet, nous avons élaboré des routes de formulation permettant de produire des films de phase cylindrique hexagonale de copolymères alignés contenant des nanoparticules d’or. L’orientation des cylindres perpendiculaires au substrat a été obtenue en déposant le copolymère grâce à un solvant neutre dont la composition dépend de la fraction volumique en PVP du copolymère. La structure des films avec et sans nanoparticules a été caractérisée par microscopie et diffusion des rayons X en incidence rasante (GISAXS). Plusieurs méthodes d’incorporation des nanoparticules d’or ont été étudiées, soit en synthétisant les nanoparticules au sein du copolymère, en solution avant dépôt ou directement dans le film organisé ; soit en incorporant des nanoparticules pré-formées, en solution de copolymère ou dans le film déposé. Dans le cas de la synthèse in situ, nous avons formé les AuNPs par réduction chimique ou physique (sonication, radiolyse) d’un sel d’or dans le copolymère. L’incorporation des AuNPs pré-formées, elle, a été réalisée grâce à la fonctionnalisation des AuNPs ou par un traitement du film de copolymère afin de faciliter l’insertion des AuNPs. / Metamaterials are artificial materials, made from the assembly of nano-resonators, which can interact with incoming waves and get properties unknown for homogeneous materials. In order to fabricate metamaterials with an effect over visible light, a precise control over the organization at the nanoscale is required. The goal of this project was then the use of bottom-up approaches to achieve the anisotropic organization of gold nanoparticles (AuNPs), which are resonators due to their plasmonic properties, into a poly(styrene)-b-poly(vinylpyridine) block copolymer film, with a nanostructuration in arrays of PVP cylindrical domains perpendicular to the substrate.During this work, we investigated routes for the fabrication of copolymer films containing ordered gold nanoparticles in a hexagonal cylindrical phase. The orientation of the cylinders normal to the substrate was obtained by casting the copolymer with a neutral solvent whose composition was found dependent on the volumic fraction of PVP in the copolymer. The film structure with and without AuNPs was characterized by microscopy and Grazing-Incidence Small-Angle X-rays Scattering (GISAXS). Several incorporation methods for the insertion of AuNPs were studied, either by the in situ synthesis of the nanoparticles in solution before casting or directly into the ordered film; or by incorporating pre-formed AuNPs in the copolymer solution or in the film as-cast. In the case of the in situ synthesis, the AuNPs were formed by chemical or physical (sonication, radiolysis) reduction of a gold salt in the copolymer. The incorporation of pre-formed AuNPs was, achieved thanks to the functionalization of the AuNPs or by a treatment of the copolymer film in order to facilitate the insertion of the AuNPs.
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O estudo do comportamento reológico de nanocompósitos de copolímeros em bloco contendo nanocargas. / Study of nanocomposite rheological behavior of block copolymers containing nanofiller.Leice Gonçalves Amurin 25 February 2014 (has links)
Neste presente trabalho foi realizado um estudo sobre copolímeros em bloco e seus nanocompósitos com diferentes estruturas morfológicas. Os polímeros estudados foram copolímeros de poliestireno-b-poli(etileno-co-butileno)-b-poliestireno (SEBS), sendo dois desses copolímeros com fração em massa de 30% de blocos de poliestireno (PS), e um deles modificado com anidrido maleico na fase de poli(etileno-co-butileno) (PEB). Os outros três copolímeros têm 13% de blocos de PS. A nanopartícula utilizada foi a argila montmorilonita organofílica Cloisite 20A. Os nanocompósitos foram preparados por dois métodos: i) mistura no estado fundido (extrusão); ii) solução. As microestruturas dos materiais resultantes foram caracterizadas pelas técnicas de espalhamento de raios X a baixo ângulo (SAXS) e difração de raios-X (DRX). As propriedades reológicas foram avaliadas em dois tipo de fluxo (cisalhamento e elongacional). Para avaliar as propriedades reológicas em fluxo de cisalhamento foram realizados ensaios de cisalhamento oscilatório em pequenas amplitudes (SAOS), cisalhamento oscilatório em grandes amplitudes (LAOS) e varredura de tempo (TS). Para avaliar as propriedades reológicas em fluxo elongacional foram realizados ensaios com geometria apropriada (SER), acoplada ao reômetro rotacional. Estes ensaios foram conduzindo em duas direções: paralela (longitudinal) e perpendicular (transversal) à direção do fluxo de extrusão. As análises de caracterização estrutural (DRX e SAXS) indicaram uma estrutura intercalada para os nanocompósitos SEBS/20A e esfoliada para as matrizes modificadas com anidrido maleico. A caracterização reológica dos copolímeros com 30% de blocos de PS em fluxo de cisalhamento mostrou que as morfologias dos nanocompósitos são estáveis com o tempo de cisalhamento, e permitiu confirmar as estruturas dos nanocompósitos. Para os copolímeros com 13% de blocos de PS foi possível identificar as temperaturas de transição ordem-ordem e ordem-desordem. Os resultados dos ensaios reológicos indicaram que ocorre alinhamento dos cilindros na direção dos fluxos de cisalhamento e elongacional. Também foram avaliadas as propriedades mecânicas, e os resultados mostraram que o comportamento mecânico é altamente influenciado pela estrutura morfológica e a incorporação de argila. / In this work block copolymers and their nanocomposites were studied. The polymers studied were copolymers of polystyrene-b-poly(ethylene-co-butylene)-b-polystyrene (SEBS), with two samples containing 30 wt% of PS blocks. The other three copolymers contained 13% of PS blocks. Two block copolymers are modified with maleic anhydride. The reinforcement used was the montmorillonite organoclay Cloisite 20A. The nanocomposites were prepared by two methods: i) melt blending (extrusion), with which a cylindrical hexagonal structure (anisotropic and isotropic) was obtained; ii) casting, with which a lamellar structure was obtained. The microstructures were characterized by the techniques of small angle X-ray scattering (SAXS) and X-ray diffraction (XRD). The rheological properties were evaluated in two different flows (shear and elongational). To evaluate the rheological properties in shear flow the samples were tested under small amplitude oscillatory shear (SAOS), large amplitude oscillatory shear (LAOS) and time sweep (TS). To evaluate the rheological properties in elongational flow, tests were carried out using an appropriate geometry (SER). The latter tests were conducted on samples aligned in two different directions: parallel (longitudinal) and perpendicular (transverse) to the flow direction of extrusion. The structural characterization analysis (XRD and SAXS) indicated an intercalated nanocomposite structure for SEBS/20A, and an exfoliated structure for the copolymers modified with maleic anhydride. The rheological characterization of the samples in shear flow showed that the morphologies of the nanocomposites are stable with time of shearing, and it confirmed the morphologies of the nanocomposites (30% PS block). For copolymers with 13 % of PS blocks it was possible to identify the order-order and order-disorder transition temperatures. The rheological tests showed that it is possible to align the morphologies in shear and elongational flows. The mechanical properties were also evaluated; the results have shown that the mechanical behavior was strongly influenced by the morphological structure and clay incorporation.
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Estudo do processamento e da orientação microestrutural em nanocompósitos de copolímeros em bloco. / Study pf processing and microstructural guidance in nanocomposites in block copolymers.Leice Gonçalves Amurin 28 July 2010 (has links)
Neste trabalho nanocompósitos de copolímero em bloco foram estudados. Os copolímeros em bloco utilizados foram o SEBS (poliestireno-b-poli(etileno-co-butileno)-b-poliestireno) e SEBSMA (que contém cerca de 2% de anidrido maléico no bloco de PEB) e as nanocargas argilas organofílicas: Cloisite 20A (modificada com 95 meg/100g de argila do sal di(alquil de sebo hidrogenado) dimetil amônio) e Cloisite 30B (modificada com 90 meq/100g de argila do sal (alquil de sebo) dihidroxietil metil amônio). Os nanocompósitos foram obtidos pelo método de mistura no estado fundido utilizando uma extrusora dupla rosca. Foram utilizados dois tipos de matrizes, sendo uma de filamento e a outra de fita. As microestruturas e propriedades dos materiais resultantes foram caracterizadas pelas técnicas de Espalhamento de Raios X a Baixo Ângulo (SAXS), Difração de Raios X (XRD), Microscopia Eletrônica de Transmissão (TEM). Foram realizados ensaios de Cisalhamento Oscilatório em Pequenas Amplitudes (SAOS) e Varredura de tempo (Time Sweep). Também, foram realizadas séries de ensaios reológicos para estudar um possível alinhamento das estruturas durante o fluxo. Em particular as amostras foram submetidas a Cisalhamento Oscilatório em Grandes Amplitudes (LAOS) e a estabilidade estrutural do material após o alinhamento. As amostras foram também testadas em fluxos extensionais utilizando-se uma geometria apropriada para gerar fluxos elongacionais. Esses últimos ensaios foram realizados utilizando dois tipos de amostras: amostras obtidas com a matriz de fita e cortadas paralelamente à direção do fluxo (longitudinal) ou perpendicularmente a direção do fluxo (transversal). As análises de caracterização estrutural (XRD e TEM) indicaram uma estrutura intercalada para o nanocompósito SEBS/20A, esfoliada para o SEBS-MA/20A e parcialmente esfoliada para o nanocompósito SEBS-MA/30B. Os resultados mostraram que as estruturas estão bem ordenadas com empacotamento hexagonal cilíndrico para ambos os copolímeros e nanocompósitos. Os resultados de caracterização estrutural mostraram que o processo de extrusão alinhou os cilindros (PS) na direção do fluxo de extrusão e as partículas de argila também sofreram uma orientação preferencial em menor escala. A caracterização reológica das amostras em cisalhamento mostrou que as morfologias dos nanocompósitos são estáveis com o tempo de cisalhamento, e permitiu confirmar as morfologias dos nanocompósitos. Os ensaios reológicos mostraram que é possível orientar as morfologias em cisalhamento e extensão. / In this work nanocomposites block copolymer were studied. The block copolymers used were SEBS (polystyrene-b-poly(ethylene-co-butylene)-b-polystyrene) and SEBS-MA (containing about 2% of maleic anhydride in the block EB), the nanocharges were organoclays namely: Cloisite 20A (modified with 95 meg/100g clay salt di (hydrogenated tallow alkyl) dimethyl ammonium) and Cloisite 30B (modified with 90 meq/100 g clay salt (tallow alkyl) methyl ammonium dihidroxietil). The nanocomposites were obtained by melt mixing using a twin-screw extruder. Two types of matrices, filament and ribbon were used. The microstructures and properties of the resulting materials were characterized by Small Angle X-Ray Scattering (SAXS), X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). Small Amplitude Oscillatory Shear (SAOS) and Time Sweep were carried out. Sequences of rheological tests were conducted to study a possible alignment of the structures during flow. In particular, the samples were submitted to Large Amplitude Oscillatory Shear (LAOS) and recovery. The samples were also tested in extensional flows using an appropriate geometry. These latest tests were conducted using two types of samples: tape samples cut along the flow direction (longitudinal) or cut perpendicular to the flow direction (transverse). The analysis of structural characterization (XRD and TEM) indicated an intercaled structure of the nanocomposite SEBS/20A, exfoliated for SEBS-MA/20A and partially exfoliated nanocomposite for SEBS-MA/30B. The results showed that the structures are well ordered with hexagonal cylindrical packing for both copolymers and nanocomposites. The results of structural characterization showed that the extrusion process aligned cylinders (PS) in the flow direction of extrusion and the clay particles also suffered a preferred orientation on a smaller scale. The rheological characterization of the samples in shear showed that the morphologies of the nanocomposites are stable with time of shearing, and it confirmed the morphologies of the nanocomposites. The rheological tests showed that it is possible to guide the morphologies in shear and extension.
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Studies on Conformational Characteristics and Self-Assembled Structures of Polymers in Space-Limited Systems / 空間制限系における高分子のコンホメーション特性と自己組織化構造に関する研究 / クウカン セイゲンケイ ニ オケル コウブンシ ノ コンホメーション トクセイ ト ジコ ソシキカ コウゾウ ニ カンスル ケンキュウSEKINE, Ryojun 23 July 2009 (has links)
Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第14871号 / 工博第3139号 / 新制||工||1470(附属図書館) / 27293 / UT51-2009-K667 / 京都大学大学院工学研究科高分子化学専攻 / (主査)教授 伊藤 紳三郎, 教授 長谷川 博一, 教授 金谷 利治 / 学位規則第4条第1項該当
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