Orientadores: Edvaldo Sabadini, René Alfonso Nome Silva / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-27T10:23:43Z (GMT). No. of bitstreams: 1 Ito_ThiagoHeiji_D.pdf: 8761085 bytes, checksum: 521d52e10af7805f341661ecc562599c (MD5) Previous issue date: 2015 / Resumo: Micelas gigantes têm sido muito estudadas desde os anos de 1980 e suas propriedades têm atraído a atenção tanto do setor produtivo quanto acadêmico. Aumento de viscosidade, capacidade de reduzir o atrito hidrodinâmico, formação de fluidos viscoelásticos e do tipo gel, são alguns dos fenômenos que fazem deste, um sistema de interesse em ambos os setores. Na literatura, está relatada uma grande quantidade de sistemas com propriedades particulares, inclusive, responsivos a estímulos luminosos, elétricos ou mudança no pH, todas advindas de diversas combinações entre diferentes componentes. No entanto, pouco se conhece a respeito dos fatores que levam à formação (crescimento), à estabilidade e, consequentemente, aos diversos fenômenos que despertam tanto interesse desse tipo de sistema supramolecular. Neste trabalho, buscou-se compreender e sistematizar a influência da estrutura molecular de vários compostos aromáticos na capacidade de induzir a formação de micelas gigantes com surfactantes catiônicos, além de uma interpretação baseada na termodinâmica para compreender o processo de crescimento deste sistema supramolecular. Para isso foram utilizadas várias técnicas como reologia, espalhamento de luz e nêutrons, e calorimetria de titulação isotérmica, que demonstraram uma grande influência de fatores estruturais dos co-solutos aromáticos como a presença de carga, hidrofobicidade e, especialmente, a capacidade de empacotamento devido à planaridade da molécula, demostrado pela primeira vez. Além disso, os ensaios de calorimetria e espalhamento de luz elucidaram como se dá o processo de crescimento da micela, bem como, mostraram a importância que a carga superficial do agregado tem para transição entre micelas curtas e alongadas / Abstract: Giant micelles have been studied since the 1980s and their properties have attracted the attention of both the productive sector and the academic. Viscosity increase, the ability in promote hydrodynamic drag reduction, formation of viscoelastic and gel-like fluids, are some of the phenomena that turn interesting the system in both approaches. In the literature, it is reported a large number of systems showing particular properties, including light, electrical stimuli or pH responsive, resulting from combinations of several different components. However, little is known about the factors that lead to formation (growth), stability and, consequently, to many phenomena which arouse such interest on that kind of supramolecular system. In this study, we tried to understand the influence of the molecular structure of various aromatic compounds in the ability to induce the formation of wormlike micelles with cationic surfactants, and an interpretation based on thermodynamics to understand the growth process of such supramolecular system. Several techniques like rheology, light and neutrons scattering, and isothermal titration calorimetry, have been used in order to study the system, which showed the influence of structural factors of the aromatic co-solutes such as presence of electrostatic charge, hydrophobicity, and the packing capacity due the planarity of the molecule, demonstrated for the first time. Additionally, calorimetric and light scattering measurements elucidated the growth process of the micelle, and showed the importance of the surface charge in transition between small and elongated micelles / Doutorado / Físico-Química / Doutor em Ciências

Ce travail de thèse vise à apporter des connaissances structurales et fonctionnelles sur les protéines du gluten. Pour cela, nous utilisons les concepts et méthodes de la physique des polymères et de la matière molle. Plus précisément, nous optimisons un protocole d’extraction basé sur la séparation de phases liquide-liquide. Ce dernier permet d’obtenir des isolats de protéines à différents rapports massiques gluténines/gliadines que nous étudions ensuite dans un solvant eau/éthanol 50/50 (v/v). Les résultats, montrent que les protéines se comportent comme des chaînes de polymères en solvant θ, en régime dilué et semi-dilué avec des tailles caractéristiques définis par diffusion de rayons X et de neutrons aux petits angles. De plus, 2 tailles d’objets sont distinguées en régime dilué par diffusion dynamique de la lumière: d’une part des protéines monomériques de l’ordre d’une dizaine de nanomètres associées aux  et -gliadines et à des polymères de gluténines de faibles masses molaires et d’autre part des assemblages polymériques de l’ordre de 100 nm, principalement composés de ω-gliadines et polymères de gluténines de haute masse molaire. Ces assemblages sont mis en avant par une combinaison de mesures réalisées par chromatographie d’exclusion de taille et par fractionnement par flux de forces asymétrique et permettent de rationaliser les diagrammes de phases de ces mélanges protéiques, en fonction de la température. L’étude de la dynamique de séparation de phases de ces mélanges protéiques, par diffusion de rayons X aux petits angles, montre que celle-ci est pilotée par un phénomène de décomposition spinodale. Cette décomposition peut être arrêtée lors de trempes en température profondes mais également observée à toutes les températures de trempe, pour les échantillons les plus riches en gluténines, formant un gel dès le régime monophasique, d’après leur étude par rhéologie / The aim of this thesis is to provide structural and functional knowledge on wheat gluten proteins. For that, we use the physical methods and the concept of soft matter. We optimize an extraction protocol based on a liquid-liquid phase separation. With this protocol, we obtain protein batches with different glutenin/gliadin mass ratios, which we then study in a 50/50 water/ethanol solvent (v/v). We show that proteins behave like polymer chains in θ solvent in dilute and semi-dilute regime, whose characteristic size are extracted by small angle X-ray and neutron scattering. Moreover, two sizes of objects are evidenced in dilute regime by dynamic light scattering: monomeric proteins with a size around 10 nm which can be associated to α/β, and γ-gliadins and polymeric glutenins with low molecular weight and polymeric assemblies with a size around 100 nm composed of ω-gliadins and glutenins polymers with high molecular weight. These assemblies are revealed by a combination of size exclusion chromatography and asymmetric flow field flow fractionation and allow one to rationalize the phase diagrams of the protein mixtures with temperature. The study of the dynamics of the phase separation of these protein mixtures by small angle X-ray scattering shows that the phase separation proceeds through a spinodal decomposition phenomenon. An arrested phase separation is observed for deep quenches but also at all temperature quenches for the most glutenin rich samples, which are gels in the monophasic regime, as confirmed by rheology.

Thesis The main objective of this thesis is the study of boron cluster compounds in solution, their interaction with polymers and the formation of nanostructures. Most of the work was focused around cobalt bis(dicarbollide) (COSAN) but the incorporation of carborane into polymers was also studied. The idea was to close the knowledge gap around the way COSAN aggregates and continue the line of the laboratory in leading this topic. Therefore, we performed in-depth analysis of isothermal titration calorimetry curves to determine the aggregation number at concentrations around the critical micellar concentration (CMC). Thus, the aggregation number obtained was an improvement over previous data obtained a much higher concentration. The use of acetonitrile as a cosolvent in the micellization process helped formulate a model describing how C-H bonds in the COSAN micelles are directed towards the inside of the micelle. Furthermore, COSAN was used as a model drug for loading nanocarriers composed of hydrophobic core and charged corona. The importance of this work relies on the creation of guidelines for drug loading into similar polymeric vectors in order to determine how the nanocarrier will be affected. With the help of coarse-grained simulations, we determined that changes in the hydrophobicity of the...

[pt] A interação entre polímeros e surfactantes de cargas opostas frequentemente resulta na formação de coacervados e pode ser utilizada para promover a deposição de produtos capilares. A compreensão dos efeitos da estrutura molecular, concentração de surfactantes e polímeros, e força iônica é essencial para controlar esse fenômeno. Este estudo utilizou polímeros e surfactantes de cargas opostas que já são aplicados na indústria cosmética: Lauril Éter Sulfato de Sódio (SLES), Lauril Éter Sulfosuccinato Dissódico (SS), Lauroil Sarcosinato de Sódio (LS), Poli(dialildimetilamônio) (PDADMAC) e Hidroxietilcelulose Cationizada (cat-HEC). Para compreender como a estrutura molecular afeta a coloidal na coacervação induzida por diluição, foi usada uma faixa de concentração típica de produtos, o que é raro de se encontrar na literatura. Caracterizamos as amostras pelas técnicas de potencial zeta, espalhamento de raios X a baixos ângulos e microscopia óptica. A deposição sobre fios de cabelo foi avaliada por microscopia óptica e de força atômica. Os sistemas concentrados de SS e LS+PDADMAC foram uma solução micelar que, quando diluídos, se separaram em uma mesofase cúbica Pm3n. O sistema SLES+PDADMAC demonstrou separação de fases mesmo em concentrações elevadas e o planejamento de misturas revelou que pequenas variações na quantidade de PDADMAC têm impacto significativo. O estudo com cat-HEC mostrou que o recobrimento do fio de cabelo pode ocorrer mesmo sem a coacervação, sendo mais dependente da natureza do polímero. Assim, o trabalho correlacionou estruturas coloidais de diferentes sistemas com propriedades macroscópicas possibilitando um controle estratégico de formulações capilares. / [en] The interaction between oppositely charged polymers and surfactants often leads to the formation of coacervates and can be employed to facilitate the deposition of hair care products. Understanding the e ffects of molecular structure, surfactant and polymer concentrations, and ionic strength is essential for controlling this phenomenon. This study utilized polymers and surfactants with opposing charges that are already employed in the cosmetic industry: So dium Laureth Sulfate (SLES), Disodium Laureth Sulfosuccinate (SS), Sodium Lauroyl Sarcosinate (LS), Poly(diallyldimethylammonium chloride) (PDADMAC), and Cationized Hydroxyethylcellulose (cat HEC). To understand how molecular structure affects colloidal st ructure in dilution induced coacervation, a typical concentration range of products was used, which is rare to find in the literature. We employed zeta potential analysis, low angle X ray scattering, and optical microscopy to characterize the materials. De position on hair strands was assessed through optical and atomic force microscopy . The concentrated SS and LS+PDADMAC systems formed micellar solutions that phase separated into a Pm3n cubic mesophase upon dilution. The SLES+PDADMAC system exhibited phase separation even at high concentrations, with mixture design revealing that small variations in the PDADMAC amount had a significant impact. The study with cat HEC demonstrated that hair strand coating could occur even without coacervation, being more depen dent on the nature of the polymer . As a result, this work established a correlation between colloidal structures in different systems and macroscopic properties, enabling strategic control of hair care formulations.

Les propriétés mécaniques de films polymériques peuvent être considérablement améliorées par l'inclusion de nanoparticules au sein de la matrice du fait de deux effets majeurs : (i) la structure locale de la dispersion des charges et (ii) la modification potentielle de la dynamique et de la conformation des chaînes à l'interface charge/polymère. Néanmoins, les mécanismes précis qui permettent de relier ces contributions à l’échelle nanométrique aux propriétés macroscopiques des matériaux, et en particulier aux propriétés mécaniques, sont actuellement mal décrits. Dans ce contexte, nous avons synthétisé des nanocomposites modèles à base de nanoparticules magnétiques de maghémite γ-Fe2O3 (nues ou greffées d'une couronne de polystyrène (PS) par polymérisation radicalaire contrôlée) dispersées dans une matrice de PS, que nous avons caractérisé en couplant la diffusion de rayonnement (Rayons X et neutrons) et la microscopie électronique à transmission. En jouant sur différents paramètres tels que la taille des particules, la concentration, ou le rapport de taille entre les chaînes greffées et celles de la matrice pour les charges greffées, nous avons obtenu des nanocomposites présentant un éventail de dispersions de charges variées, contrôlées, parfaitement reproductibles, allant de particules individuelles ou d’agrégats ramifiés jusqu’à la formation d’un réseau de charges connecté. En appliquant un champ magnétique externe durant la synthèse des nanocomposites, nous sommes parvenus à aligner les différentes structures le long de la direction du champ et ainsi former des matériaux présentant des propriétés remarquables de renforcement anisotropes. La conformation des chaînes au sein des nanocomposites, déterminée expérimentalement grâce aux propriétés spécifiques de contraste neutronique du système, n'est pas affectée par la présence des charges, quels que soient le degré de confinement des chaînes, l’orientation, la dispersion ou l'état de surface des charges. L’alignement des charges sous champ magnétique a permis de décrire précisément l’évolution du module de renforcement des matériaux avec la réorganisation structurale locale des charges et des chaînes sous étirement, et de finalement mettre en évidence le rôle majeur joué par la réorganisation des charges sous déformation dans les mécanismes de renforcement. / The mechanical properties of polymeric nanocomposite films can be considerably enhanced by the inclusion of inorganic nanoparticles due to two main effects: (i) the local structure of fillers dispersion and (ii) the potential modification of the chains conformation and dynamics in the vicinity of the filler/polymer interface. However, the precise mechanisms which permit to correlate these contributions at nanometric scale to the macroscopic mechanical properties of the materials are actually poorly described. In such a context, we have synthesized model nanocomposites based on magnetic nanoparticles of maghemite γ-Fe2O3 (naked or grafted with a polystyrene (PS) corona by radical controlled polymerization) dispersed in a PS matrix, that we have characterized by combining small angle scattering (X-Ray and neutron) and transmission electronic microscopy. By playing on different parameters such as the particle size, the concentration, or the size ratio between the grafted chains and the ones of the matrix in the case of the grafted fillers, we have obtained nanocomposite films a large panel of controlled and reproducible controlled filler structures, going from individual nanoparticles or fractal aggregates up to the formation of a connected network of fillers. By applying an external magnetic field during the film processing, we succeeded in aligning the different structures along the direction of the field and we obtained materials with remarkable anisotropic reinforcement properties. The conformation of the chains of the matrix, experimentally determined thanks to the specific properties of neutron contrast of the system, is not affected by the presence of the fillers, whatever their confinement, the dispersion the fillers or their chemical state surface. The alignment of the fillers along the magnetic field has allowed us to describe precisely the evolution of the reinforcement modulus of the materials with the structural reorganization of the fillers and the chains at the local scale under stretching, and thus to highlight the key role played by the fillers reorganization under stretching on the nanocomposite reinforcement mechanisms.

Dans l’industrie du pneumatique, l’incorporation de nanoparticules de silice dans les élastomères permet d’obtenir des pneumatiques avec des propriétés mécaniques améliorées. D’un point de vue fondamental, deux contributions sont communément invoquées pour expliquer ces changements : (i) une contribution du réseau de charges, fortement dépendante de leur état de dispersion, (ii) une contribution des chaines dont la conformation est potentiellement modifiée en présence du réseau de charges. Cependant, les mécanismes permettant de relier cette structure nanométrique aux propriétés macroscopiques du matériau sont encore mal compris. Dans ce contexte, nous avons synthétisé des systèmes SBR/Silice modèles constituant une première approche de systèmes industriels plus complexes. En modifiant les conditions de dispersion au moyen d’agent de greffage, nous avons obtenu des nanocomposites avec des dispersions variées et reproductibles, avec des organisations multi-échelle. Celles-ci ont été caractérisées finement par l’utilisation combinée de la Diffusion de Rayons X aux Petits Angles (DXPA) et de la Microscopie Electronique en Transmission (MET). La conformation des chaines, déterminée expérimentalement par Diffusion de Neutrons aux Petits Angles (DNPA), n’est pas affectée par un effet à longue distance des charges. La caractérisation quantitative de la dispersion a permis de mettre en évidence le rôle prépondérant de la compacité des agrégats de silice et de la densité de leur réseau sur le renforcement dans le régime élastique. / In tire industry, the incorporation of nano-sized silica in rubber leads to elastomeric materials with enhanced mechanical properties. In a fundamental approach, two main contributions are commonly accepted to explain these changes: (i) a first from the filler network highly depending on their dispersion, (ii) a second from the chains whose the conformation is potentially modified by the filler network. However, the mechanisms which permit to correlate these nanometric structural properties to the macroscopic mechanical properties are still poorly understood. In such a context, we have synthesized model nanocomposites SBR/silica systems constituting a first approach of more complex industrial systems. By varying dispersions conditions by using grafting agents, we have obtained various and reproducible dispersions, with multi-scale organizations. They have been finely characterized by combining Small Angle X-Ray Scattering (SAXS) and Transmission Electron Microscopy (TEM). Chain conformation experimentally determined by Small Angle Neutron Scattering (SANS) is not affected by any long range effect of fillers. The quantitative characterization of filler dispersions has shown the major role of silica aggregates compactness and the density of their network on the reinforcement in the elastic regime.

Le but de cette thèse était de comprendre l'organisation supramoléculaire et le possible réarrangement dynamique de copolymères supramoléculaires multifonctionnels. Ainsi, nous avons synthétisé diverses molécules présentant un coeur urée ou pérylène fonctionalisé par différentes chaines latérales afin de combiner des propriétés de structuration, de fluorescence et de bioreconnaissance dans une même chaine de polymère supramoléculaire. En combinant différentes techniques de spectroscopie, de diffusion du rayonnement et de microscopie, nous avons montré que des molécules avec un même coeur mais des chaines latérales différentes conduisaient à des nanostructures différentes comme des rubans vrillés, des plaques 20 ou encore des fibres branchées. Enfin, plusieurs unités monomériques avec un même coeur mais des chaines latérales différentes ont été mélangées pour former des copolymères supramoléculaires multifonctionnels. La formation préférentielle d'une nanostructure unique dictée par un des monomères a été démontrée selon un mécanisme de tri dit social ( « social self-sorting » ). / The goal of this thesis was to understand the supramolecular organization and the possible dynamic rearrangement of multifunctional supramolecular copolymers. To this end, we havedeveloped a series of building blocks based on urea or perylene cores with various lateral side chains for combining structuring, fluorescence, and biorecognition properties in a singlesupramolecular polymer chain. Using a combination of spectroscopy, scattering, and microscopy techniques, we have shown that molecules with a same core but different lateral chains can lead to the formation of various nanostructures su ch as twisted ribbons, 20 plates, or branched fibers. Ultimately, by combining monomeric units with different functional side chains, multifunctional supramolecular copolymers have been obtained. Whereas radiation scattering and imaging techniques were used to demonstrate that one of the monomer can dictate the formation of a preferential nanostructure, optical spectroscopies revealed that the polymerization process of our systems indeed occurs via social self-sorting.

Optical scattering techniques are suitable probes for studying weak disordered refractive index media such as biological cells and tissues. Several brain diseases accompany the nano-to-submicron scales’ structural alterations of the basic building blocks of cells/tissues in the brain and skin fibroblasts. For example, several molecular modifications such as DNA methylation, and histone degradation occur in cells earlier than morphological changes detectable at a microscopic level. These alterations also change the refractive index structures of the cells/tissues at the nano-to-submicron scales. Unfortunately, traditional methods do not allow the detection of these alterations in the early stages of diseases. Recent developments in mesoscopic optical physics-based techniques can probe these alterations. Particularly, mesoscopic light transport and localization approaches enable the measurements and quantifications of the degree of structural alterations in the cells/tissues and unprecedented information on progressive brain diseases. This dissertation provides a detailed study of the structural changes at nano-to-submicron levels in human brain cells/tissues and human skin fibroblasts in two major neurodegenerative diseases, Alzheimer’s disease (AD) and Parkinson's disease (PD), using dual spectroscopic imaging techniques, namely partial wave spectroscopy (PWS) for light transport and inverse participation ratio (IPR) for weak light localization. In particular, a nanoscale-sensitive advanced PWS technique is used to quantify the structural alterations in cells/tissues. Further, the IPR technique is used to quantify molecular-specific mass density alterations within cells using their light localization properties via confocal imaging. These dual optical scattering techniques were utilized to measure the degree of structural disorders, termed ‘disorder strength’, by distinguishing the diseased cells/tissues from normal ones in the human brain and human skin fibroblasts due to neurodegenerative diseases. Our results show that the degree of structural disorder (����) increases in the affected cells and tissues relative to the normal, both at the cellular/tissue level and in the DNA molecular mass density structural levels. The results of the studies strongly reveal that the degree of structural disorder strength (����) is an effective biomarker/numerical indicator for brain disease diagnostics.