CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / SÃlicas mesoporosas do tipo SBA-15 funcionalizadas com amino (âNH2) foram preparadas para o desenvolvimento de adsorventes de metais pesados em Ãguas residuais. A funcionalizaÃÃo com grupos orgÃnicos tem sido realizada por dois mÃtodos distintos, pÃs-sÃntese e co-condensaÃÃo. Neste trabalho a matriz foi preparada por co-condensaÃÃo e dois grupos orgÃnicos foram selecionados para serem incorporados aos sÃtios de grupos amino: cisteÃna (HSâCH2âCH(NH2)âCOOH) e fenilisotiocianato (C6H5âNCS). Os materiais foram caracterizados por difraÃÃo de raios X em baixo Ãngulo (DRX), Microscopia EletrÃnica de Varredura (MEV), Microscopia EletrÃnica de TransmissÃo (MET),RMN no estado sÃlido, AdsorÃÃo-dessorÃÃo de nitrogÃnio, anÃlise tÃrmica (TG/DTG) e Espectroscopia na RegiÃo do Infravermelho (FT-IR). O material hÃbrido SBA-15_NH2 exibiu Ãrea superficial BET de 451 m2/g e volume total de poros de 0,15 cm3/g. FT-IR, RMN no estado sÃlido e TG/DTG confirmaram a incorporaÃÃo das cadeias orgÃnicas da cisteÃna e fenilisotiocianato nos materiais. As anÃlises indicaram que todas as amostras sintetizadas apresentaram estrutura hexagonal, caracterÃstica dos materiais mesoporosos do tipo SBA-15, com boa ordenaÃÃo dos poros, elevada Ãrea superficial e estreita distribuiÃÃo de tamanhos de poros. Todas as amostras modificadas foram submetidas a processos de sorÃÃo de Ãons Cu2+. A capacidade de adsorÃÃo mÃxima foi de 21 mg/g para o material modificado com fenilisotiocianato. A isoterma de Langmuir ajustou-se melhor aos dados experimentais e associado com o modelo de pseudo-segunda ordem descreveu bem o processo cinÃtico de adsorÃÃo. Os resultados sugerem que esses materiais podem ser usados como adsorventes para remoÃÃo de Ãons de metais traÃos em sistemas aquosos contaminados. / SBA-15 Mesoporous silica functionalized with amine (â NH2) hat been prepared in this work for the purpose of the development of heavy metals adsorbents from wastewater. The functionalization with organic groups has been performed by two different methods, post-synthesis and co-condensation. In this work, the matrix was prepared by co-condensation. Two organic groups were selected to be incorporated with specific reactions sites containing amino groups, cysteine (HSâCH2âCH(NH2)âCOOH) and phenylisotiocianate (C6H5âNCS). The materials were characterized by X-ray Diffraction at low angle (XRD), Scanning Electronic Microscopy (SEM), Transmission Electron Microscopy (TEM), Nuclear Magnetic Resonance Solid State (NMR), Nitrogen adsorption-desorption (BET), Thermal Analysis (TG/DTG) and Spectroscopy of the Infrared (FT-IR). The hybrid material SBA 15_NH2 exhibit BET surface area of 451 m2/g and total pore volume 0,15 cm3/g. FT-IR, NMR, TG confirmed the incorporation of organic groups, cisteine and phenylisotiocianate in the materials. The analysis indicated that all synthesized materials showed hexagonal structure, characteristic of mesoporous materials like SBA-15 with good ordering of the pores, high surface area and narrow pore size distribution. All modified samples were subjected of sorption processes of Cu+2. The maximum adsorption capacity was 21 mg/g for the material modified with phenylisotiocianate. The Langmuir isotherm model fitted well to the experimental data together of pseudo-second order model kinetic process of adsorption. The results suggest that these materials can be used as adsorbents to remove trace metal ions in contaminated aqueous systems.

A importância que a catálise representa para a sociedade pode ser vista em números: 90% dos processos da indústria química e mais de 20% de todos os produtos industriais comercializados no mundo utilizam uma ou mais etapas catalíticas. Assim, desenvolver catalisadores eficientes, ativos e seletivos é a solução para criar tecnologias mais limpas e sustentáveis. Além disso, reações químicas que geram novas ligações C-C estão entre as transformações mais relevantes na química orgânica e são a base desse trabalho. Os catalisadores de ródio apresentados aqui fazem parte de um trabalho minucioso de desenvolvimento, síntese e caracterização de nanopartículas e suportes magnéticos funcionais que foram utilizados em transformações de diversas moléculas. O estudo inicial com nanopartículas de ródio suportadas, em reações de hidrogenação do cicloexeno, serviu para a compreensão de como se comportam essas nanoestruturas e da influência que diferentes ligantes orgânicos e estabilizantes podem ter em uma aplicação catalítica bastante conhecida. O sistema catalítico mostrou-se bastante ativo e reutilizável,despertando o nosso interesse ao seu aperfeiçoamento para aplicação em reações de hidroformilação. Antes da síntese de catalisadores suportados, estudos com nanopartículasnão-suportadas mostraram que um sistema modificado pela adição de fosfinas era necessário para ativação do catalisador e que o estabilizante utilizado afetava a atividade catalítica. Assim, para possibilitar o ancoramento eficiente das espécies ativas, uma modificação da superfície do suporte magnético com a metildifenilfosfina foi realizada. A fosfina funcionalizada sobre o suporte viabilizou sua interação com as espécies ativas e evitou a sua lixiviação, possibilitando o reuso do catalisador. A reação de hidroformilação do oct-1-eno atingiu 96% de conversão e 82% de seletividade para aldeídos, em 6 horas a 80°C. A carga metálica do catalisador foi de apenas 0,2%. Buscando aumentar a eficiência na etapa de imobilização do metal e uma melhor atividade catalítica que possibilitasse o uso de substratos mais complexos, o suporte magnético foi modificado com um polímero hiper-ramificado. Essa modificação possibilitou aumentar a quantidade de grupos fosfinas sobre o suporte, assim como levou a um significativo aumento na carga de metal. A reação de hidroformilação de produtos naturais foi possível e, com o composto estragol, conversões de 100% foram alcançadas em 6 horas, com seletividade de 70% para aldeídos. Mesmo com evidências que sugerem a formação de espécies ativas moleculares, o suporte modificado possibilitou que o catalisador mantivesse sua atividade e seletividade por pelo menos seis reações sucessivas. Os materiais desenvolvidos apresentaram estabilidade quando manuseados ao ar, sem prejudicar sua vida útil e fácil separação. / The importance of catalysis to society may be seen in numbers: 90% of chemical production processes and more than 20% of all industrial products sold in the world use one or more catalytic steps. Thus, the development of efficient, active, and selective catalysts is crucial for creating cleaner and sustainable technologies. In addition, chemical reactions that generate new C-C bonds are among the most important transformations in organic chemistry and are the basis of this work. Rhodium catalysts presented herein are part of a careful investigation, which included the development, synthesis and characterization of metal nanoparticles and magnetic functional supports for use in the transformation of various molecules. The initial study of supported rhodium nanoparticles in cyclohexene hydrogenation reactions has driven our understanding of the behavior of these nanostructures, and the influence that different ligands and stabilizers may have in a well-known catalytic application. The identification of a highly active and recyclable catalytic system aroused our interest for its improvement for application in hydroformylation reactions. Prior to the synthesis of supported catalysts, studies with non-supported nanoparticles revealed that a modified system with the addition of phosphines was required for activation of the catalyst and the stabilizer used affected the catalytic activity. Thus, to enable efficient immobilization of the active species, the surface of the magnetic support was modified with methyldiphenylphosphine. The catalyst preparation removed, at least partially, the stabilizer adsorbed on the nanoparticles surfaces. The phosphine-functionalized support anchored the active species and avoided their leaching, allowing the reuse of the catalyst. The hydroformylation reaction of oct-1-ene reached 96% of conversion and 82% of selectivity to aldehydes, in 6 hours at 80°C. The metal loading of the catalyst was only 0.2%. Seeking to increase the efficiency in metal immobilization step and a better catalytic activity that would enable the use of more complex substrates, the magnetic support was modified with a hyperbranched polymer, which allowed an increase in the amount of external phosphines, as well as a significant increase in metal loading on the support. The hydroformylation reaction of natural products was possible and, with the estragole compound, 100% of conversion was achieved in 6 hours with 70% of selectivity to aldehydes. Despite evidence that suggests the formation of active molecular species, the modified support has enabled the catalyst to retain its activity and selectivity for at least six successive reactions. The materials developed could be handled in air without damaging their catalytic activity, durability and separation properties.

Com o desenvolvimento da nanociência e da nanotecnologia, as nanopartículas magnéticas vêm sendo cada vez mais gerado interesse devido as inúmeras possíveis aplicações na área de catálise, diagnóstico, pigmentos, sensores, etc. Atualmente, as nanopartículas com potencialidade de aplicação em biomedicina que pode se destacar os as ferritas magnéticas os quais apresentam comportamento superparamagnético a temperatura ambiente. Além dos ligantes funcionais, as nanopartículas magnéticas são geralmente recobertas com polímeros orgânicos ou inorgânicos, destacando-se a sílica, nessa última classe. O sistemas as nanopartículas magnéticas recobertas com sílica formando um sistema casca-caroço, possibilita que o núcleo magnético se mantenha protegido por uma camada polimérica que pode conter grupos funcionais ativos, formando hidridos orgânicos-inorgânicos que devido a sua propriedade hidrofóbica ou hidrofílica dependendo da natureza do ligante de modificação de superfície. Este trabalho foi desenvolvido com intuito de obter nanopartículas magnéticas de ferrita MFe2O4, com (M= Fe, Co, Ni e Cu) com controle de tamanho, forma, composição química e estrutural, dos quais foram sintetizados pelo método de decomposição térmica utilizando diferente precursores metálicos para adequação das melhores condições de síntese. As ferritas magnéticas foram recobrimento com sílica, modificando da superfície da partícula e possibilitando caráter hidrofílico ao sistema casca-caroço, apresentando uma melhor estabilidade coloidal em dispersão aquosa devido a presença de grupos silanois na superfície, bem como uma recobrimento uniforma com apenas um núcleo magnético sem formação de aglomerados. A funcionalização com o grupo o trietoxivinilsilano, através de reações de condensação via catálise básica ou ácida, formou uma rede polimérica Si-O-Si, sendo que a presença do grupo vinil (-CH=CH2) livre na a superfície do sistema casca-caroço foi evidenciado através da técnica de FTIR. Portanto foi possível a obtenção de um sistema hibrido orgânico-inorgânico com a superfície contendo grupo que podem ser reativos, abrindo a possibilidade da utilização deste material para futuros testes de aplicações como sensor multifuncional. / In recent decades the development of nanoscience and nanotechnology, magnetic nanoparticles have been increasingly generated interest due to the numerous possible applications in the field of catalysis, diagnosis, pigments, sensors, etc. Currently, the nanoparticles with potential of application in biomedicine that can stand out the magnetic ferrites which have superparamagnetic behavior at room temperature. In addition to the functional binders, magnetic nanoparticles are generally coated with organic or inorganic polymers, especially silica in the latter class. The magnetic nanoparticle systems covered with silica forming a shell-core system allow the magnetic core to remain protected by a polymeric layer that may contain active functional groups, forming organic-inorganic hydrides that due to its hydrophobic or hydrophilic property depending on the nature of the surface modifying binder. This work was developed to obtain magnetic nanoparticles of MFe2O4 ferrite, with (M = Fe, Co, Ni and Cu) control of size, shape, chemical and structural composition, of which were synthesized by the thermal decomposition method using different precursors to suit the best conditions of synthesis. The magnetic ferrites were coated with silica, modifying the surface of the particle and allowing a hydrophilic character to the shell-core system, presenting a better colloidal stability in aqueous dispersion due to the presence of silane groups on the surface, as well as a uniform coating with only one magnetic core without formation of agglomerates. The functionalization with the triethoxyvinylsilane group, through condensation reactions via basic or acid catalysis, formed a Si-O-Si polymer network, and the presence of the free vinyl group (-CH=CH2) on the shell surface was observed by FTIR technique. Therefore, it was possible to obtain an organic-inorganic hybrid system with the surface containing the reactive group, opening the possibility of using this material for tests of future applications as multifunctional sensor.

Orientador: Oswaldo Luiz Alves / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-26T03:12:15Z (GMT). No. of bitstreams: 1 Fonseca_LeandroCarneiro_M.pdf: 4937818 bytes, checksum: 780a4e27e390c1034dc79087ec5b5fb2 (MD5) Previous issue date: 2014 / Resumo: Apesar dos tratamentos quimioterápicos vigentes, os principais fármacos antitumorais da atualidade são utilizados em doses limitadas, pois não possuem especificidade no combate às células cancerosas, atingindo também células sadias do corpo humano. As características hidrofóbicas de muitos desses fármacos dificulta ainda mais sua utilização. Nesse aspecto, as nanotecnologias ligadas à química e a biologia oferecem novas maneiras de superar tais barreiras em virtude do desenvolvimento de nanomateriais capazes de transportar o farmaco especificamente ao alvo biológico. No presente Projeto serão desenvolvidos nanocarreadores esféricos de sílica mesoporosa contendo grupos fenila (hidrofóbicos) em seu interior, cuja função é adsorver fármacos hidrofóbicos através de interações do tipo Van Der Walls no interior dos poros desses nanomateriais, mantendo sua integridade físico-química e, liberando-os posteriormente, às células alvo de maneira específica. Para otimização desses sistemas, faz-se necessário funcionalizar a superfície externa das nanopartículas com o polietilenoglicol (PEG), de modo a camuflá-las do sistema imunológico e evitar efeitos biológicos indesejáveis. Portanto, propõe-se nesse Projeto a funcionalização externa das nanopartículas porosas de sílica com PEGs com cadeias poliméricas curtas e longas, avaliar sua influência na hemólise de células vermelhas do sangue e seu comportamento físico-químico em diferentes meios potenciais de aplicação / Abstract: Despite existing chemotherapy treatments, the main antitumor drugs nowadays are used in limited doses because they have no specificity in fighting cancer cells, affecting healthy cells of the human body . The hydrophobic characteristics of many of these drugs further complicates their use. In this context, nanotechnology related to chemistry and biology offer new ways to overcome these barriers due the development of nanomaterials capable of carrying the pharmaco specifically to the biological target. In this Project spherical mesoporous silica nanocarriers will be developed containing phenyl groups ( hydrophobic ) in its interior , whose function is to adsorb hydrophobic drugs inside the pores through interactions like Van Der, maintaining its physical and chemical integrity and subsequently releasing the latter to target cells in a specific manner. To optimize these systems, it is necessary to functionalize the outer surface of the nanoparticles with polyethylene glycol (PEG) in order to camouflage them from the immune system and prevent undesirable biological effects. Therefore, it is proposed the outer functionalization of porous silica nanoparticles with PEG with short and long polymer chains , evaluate its influence on hemolysis of red blood cells and their physical and chemical behavior and potential application in different ways / Mestrado / Quimica Inorganica / Mestre em Química

Ce manuscrit est consacré à l’élaboration et à la photofonctionnalisation des monolithes de silice pour les techniques séparatives miniaturisées. La partie bibliographique situe d’abord l’intérêt des monolithes dans les techniques séparatives miniaturisées. L’état d’art sur l’utilisation des monolithes de silice dans ces techniques séparatives est ensuite établi en portant une attention particulière sur leur utilisation dans l’analyse d’échantillons biologiques et/ou environnementaux (préparation d’échantillons couplée aux méthodes séparatives ou utilisation de colonne de grande longueur). Un descriptif de la synthèse des monolithes de silice par le procédé sol gel est ensuite détaillé. Enfin, une étude des différentes méthodes de fonctionnalisation des monolithes de silice est présentée. L’optimisation des paramètres expérimentaux de la synthèse sol-gel a conduit à un procédé de synthèse robuste et répétable de capillaires monolithiques de silice de grandes longueurs et d’efficacités élevées (efficacités de l’ordre de 160 000-200 000 plateaux/m). Le travail expérimental s’est ensuite orienté sur l’optimisation de procédés de fonctionnalisation par voie thermique et sur le développement de nouveaux procédés de photopolymérisation ou de photografting par « photo click chemistry ». Les résultats obtenus dans des modes chromatographiques variés après photofonctionnalisation avec différents monomères montrent que ces procédés sont polyvalents et qu’un contrôle des paramètres permet de conserver les performances chromatographiques du matériau de départ. Outre sa simplicité et sa rapidité, cette approche permet de définir et de localiser différentes chimies de surface au sein d’une même colonne. Cette spécificité a été mise à profit pour le couplage en ligne dans une colonne de nanochromatographie, d’une étape de préconcentration avec une étape de séparation de neuropeptides modèles / This manuscript is dedicated to the development and functionalization of monolithic silica stationary phases for miniaturized separation techniques. The bibliographic section first summarizes the interest of monolithic phases for the development of miniaturized separation techniques and their advantages over their particulate counterparts (small particles or core shell ones). The state of the art on the use of silica monolithic columns in separation techniques is then established, with a focus on their use in the analysis of biological and/or environmental samples (coupling sample preparation with an analysis method or using long columns). Then a detailed description of the sol gel synthesis of monolithic silica is presented. Finally, a study of different established methods of functionalization of silica monoliths is presented and the potential of photofunctionalization is highlighted for the rapid and homogeneous in-situ functionalization of monolithic capillaries. The experimental part focuses first on the development and optimization of a robust process of synthesis of monolithic silica capillary columns (efficiencies around 160 000-200 000 plates/m). The work is then focused on the improvement of classical functionnalization processes and on the development of new photofunctionalization ways (photopolymerization and photo click chemistry) of silica monolithic columns. The results obtained after photofonctionnalisation in various chromatographic modes (from ion exchange to reversed phase and HILIC) mode with different monomers show that these methods are versatile and that the control of the parameters allows keeping the chromatographic performances of the starting material. Besides its simplicity and speed, this approach allows to define and to locate different surface chemistries in the same column. This specificity has been exploited to the in-line coupling a preconcentration step with a separation step in a single column, for the separation of model neuropeptides

Des nouvelles méthodes de gélification avec association de différents composés permettent l’élaboration d’hydrogels sous forme de matrices 3D présentant des propriétés optimales et des fonctions intéressantes. Cette technique d’assemblage peut être effectuée par mélange de plusieurs polymères ou/et par incorporation de nanoparticules dans la matrice polymérique. Ce travail de thèse a montré l’intérêt de mettre en œuvre des réseaux interpénétrés de polymères à base d’alginate et de GelMA, et a mis en évidence l’effet de l’incorporation de nanoliposomes sur les propriétés physico-chimiques des hydrogels. Une caractérisation multi-échelle des hydrogels, a été complétée par une étude des interactions possibles au sein de la matrice 3D. Dans une première partie du travail, une analyse des propriétés de surface des matrices composites à différentes concentrations d’alginate, avant et après fonctionnalisation par des nanoparticules molles, a montré une amélioration de la mouillabilité et de l’énergie de surface des hydrogels. Les propriétés mécaniques des hydrogels ont été déterminées par une caractérisation multi-échelle incluant la microscopie à force atomique (nanoscopique) et le rhéomètre (mésoscopique). Ces analyses ont pris en compte les différentes concentrations d’alginate ainsi que les deux concentrations différentes de liposomes incorporés dans la matrice 3D. Les résultats obtenus ont montré l’intérêt de l’assemblage des deux polymères et l’effet des nanoliposomes sur le processus de gélification de l’alginate dû à une interaction entre les nanoparticules molles et l’agent réticulant (CaCl2). Une étude morphologique des hydrogels a montré la possibilité de contrôler la taille des pores en modifiant la concentration des différents composants des hydrogels ou en fonctionnalisant les matrices 3D par des nanoparticules molles. Les interactions physico-chimiques ont ensuite été étudiées par Spectroscopie de Photoélectrons X, spectroscopie de Résonance Magnétique Nucléaire et Spectroscopie Infrarouge à Transformée de Fourier / Novel crosslinking methods to design 3D hydrogels consist on an innovative combination of various components in order to create 3D structure with optimal properties and functionalities. This blending technic can be carried out by mixing several polymers or/and incorporation of nanoparticles into the polymer network. The present work showed the advantages of interpenetrating polymer networks forms composed of alginate and GelMA and highlighted the effect of the incorporation of nanoliposomes on the physico-chemical properties of the hydrogels. It consisted primarily on a multiscale characterization of the hydrogels and then on the study of the possible interactions in the 3D structure. At first, the surface characterization of the composite hydrogels at different alginate concentrations, before and after the functionalization with soft nanoparticles, showed an improvement of the wetting properties and the surface energy. The mechanical properties of the hydrogels were determined by multiscale analysis using the atomic force microscopy (nanoscopic) and the rheometer (mesoscopic). These analysis took into account the various concentrations of alginateas well as the two different concentrations of the liposomes added in the 3D structure. The results showed the effectiveness of mixing the polymers and the influence of the nanoliposomes on the alginate coagulation due to an interaction between the soft nanoparticules and the coagulation agent (CaCl2). A morphological study of the hydrogels showed the possibility to control the size of the pores by the modification of concentration for each component of hydrogel or by functionalization the 3D structure. The physicochemical interactions were then studied thanks to the X-ray Photoelectron Spectroscopy, the Nuclear Magnetic Resonance Spectroscopy and the Fourier Transform Infrared spectroscopy

Purpose: Current DNA detection techniques require complicated procedures, specialized training, expensive equipment, invasive samples and significant amount of sample collection and processing time. The purpose of this research was to develop a rapid, accurate, non-invasive and electronic method of DNA sensing that harnesses natural unwinding properties of DNA helicase by attaching it to Carbon Nanotubes. Methods: a. A literature review on methods of attaching proteins to carbon nanotubes was conducted b. A design of the biosensor was developed based on previously reported attachment methods for other proteins c. A part of the sensor was developed by attaching DNA helicase to carbon nanotubes d. The result was tested for preservation of helicase functionality and carbon nanotube electronic structure integrity Results: a. Helicase was successfully attached to carbon nanotubes b. Helicase was found to retain its NTP hydrolysis function, DNA binding and DNA unwinding ability upon attachment c. Carbon nanotube electronic structure and function was not compromised upon attachment Conclusions: Non-specific attachment of helicase to carbon nanotubes preserves enzyme structure and function, allowing rapid DNA unwinding at an in vitro rate comparable to DNA helicase.

L'avenir de l'industrie chimique réside dans le développement de nouvelles méthodes de synthèse, et notamment dans la mise en place de réactions catalytiques et l'utilisation de milieux réactionnels performants. Ainsi, le but de ce travail de recherche doctorale était de développer des tensioactifs catalytiques à base de polyoxométallates pour effectuer des réactions de catalyse d'oxydation de substrats organiques en microémulsion. Ce travail de recherche a débuté par la synthèse et la caractérisation de nouvelles familles de tensioactifs à base de polyoxométallates, et le contrôle de la nature des contre-ions a permis de mettre au point des molécules hydrosolubles. Ces molécules amphiphiles ont été utilisées pour effectuer de la catalyse d'oxydation en phase homogène dans des solvants usuels et "verts". L'étude de la catalyse a permis d'apporter une contribution à la compréhension des sites actifs de la catalyse d'oxydation. L'étude des propriétés d'agrégation de plusieurs de ces familles de polyoxométallates amphiphiles a été menée par des techniques de caractérisation physico-chimique telles que le SAXS et la RMN et a montré la formation de micelles. L'étude de l'hydrolyse des polyoxométallates amphiphiles en solution aqueuse a mis en évidence le rôle primordial du contrôle du pH sur la stabilité des POMs amphiphiles en solution aqueuse. Une microémulsion stabilisée par des polyoxométallates amphiphiles a été décrite pour la première fois et caractérisée par SAXS et par RMN HMQC. La catalyse d'oxydation en microémulsion n'a pas pu être réalisée à cause de l'inhibition et/ou hydrolyse du catalyseur en présence d'eau. / The future of the chemical industry lies in the development of new synthetic methods, especially in setting up catalytic processes and in using new and efficient media. The aim of this doctoral research was to develop polyoxometalate based catalytic surfactants to catalytically oxidize organic substrates in microemulsions. This research begun with the synthesis and the characterization of new polyoxometalate based surfactant families, and water soluble molecules could be obtained by controlling the nature of the counterions. These amphiphilic molecules were used to make a homogeneous oxidation catalysis in most commonly used organic solvents and so-called green solvents. The study of the catalysis contributed to the understanding of active sites. The study of the aggregation properties of some of our amphiphilic POMs was carried out using physicochemical characterization techniques such as SAXS and NMR, and the formation of micelles was evidenced undoubtedly. One drawback of our system is the slow hydrolysis of the phosphonylated group grafted onto the POM framework in water, which has been showed to be accelerated in acidic conditions. Despite this degradation, we succeeded in stabilising a microemulsion by amphiphilic polyoxometalates for the first time, and we characterized it by SAXS and NMR HMQC. The oxidation catalysis in microemulsion couldn’t be carried out because of the catalyst inhibition and/or hydrolisis in presence of water.

Les prothèses diaphragmatiques en ePTFE utilisées dans la hernie diaphragmatique congénitale à large défect ont une faible étirabilité, ce qui entrainera des récidives herniaires au cours de la croissance de l’enfant. En effet, l’analyse en imagerie montre que la surface du diaphragme grandit de 4-5 fois jusqu’à l’adolescence. De plus, les mesures de rigidité des surfaces de prothèses explantés, montrent l’influence des contraintes mécaniques appliquées sur la structure des matrices extracellulaires néoformées. Afin de favoriser l’intégration tissulaire du ePTFE, nous avons testé un moyen de fonctionnaliser le ePTFE avec la polydopamine sur une seule face. Le revêtement nanoscopique favorise la colonisation cellulaire. Enfin, ce travail de thèse présente une méthode originale de réalisation d’une nouvelle membrane bicouche avec des propriétés mécaniques conformes aux exigences chirurgicales. Ce biomatériau innovant et prometteur fait actuellement l’objet d’une Déclaration d’invention. / Electron microscopy assessments of ePTFE prosthesis explants for diaphragmatic congenital hernia repair strongly suggest that the tissue responses are directly related to the surface microstructure of the biomaterial. AFM measurements (Young moduli) emphasize the influence of the mechanical stress applied to the implant on the mechanical properties of the newly formed extracellular matrices. In order to guide the host responses, we undertook to functionalize with polydopamine the ePTFE biomaterial. Electron microscopy investigations reveal the interest of that surface treatment regarding cell colonization of implant. To optimize that approach, we developed an original method aimed to coat only one face of the biomaterial. After determination of the growth rate of the diaphragm from birth to adolescence, we explored the possibility to design a new double-faced mesh able to follow body growth. From this point of view, the initial prototypes are promising and under patent application.

La fonctionnalisation chimique de surfaces hétérogènes (fonctionnalisation orthogonale) est une méthode efficace pour diriger l’ancrage de diverses cibles (biomolécules ou nano-objets) sur des zones précises prédéfinies sur un substrat. Ceci est particulièrement intéressant dans le domaine des biocapteurs à plasmons localisés (LSPR) où la transduction ne peut se faire que sur des nano- structures métalliques. L’enjeu est alors d’assurer que les molécules à détecter se fixent spécifiquement sur ces nanostructures et ne s’adsorbent pas sur la surface diélectrique environnante. Dans ce but, nous avons développé dans cette thèse des fonctionnalisations orthogonales de surfaces micro et nanostructurées d’or sur silice à l’aide de divers thiols et silanes. Par rapport à l’état de l’art dans ce domaine, nous avons notamment proposé un protocole en une seule étape et démontré la bonne orthogonalité de ces fonctionnalisations par différentes méthodes de caractérisation chimique de surface (notamment PM-IRRAS, XPS et ToF-SIMS). De plus, ces fonctionnalisations sélectives ont permis l’ancrage spécifique de diverses nanoparticules de latex sur des micro et nanostructures d’or entourées de silice, démontré par MEB. Actuellement, cette méthodologie est en cours d’application dans deux composants photoniques différents où l’on attend d’une part des effets d’exaltation de fluorescence par couplage de nano-antennes et nanobilles marquées et d’autre part un gain en sensibilité d’un biocapteur LSPR pour la détection de différentes biomolécules. / Orthogonal surface chemical functionalization is an efficient method for the selective trapping of different targets (biomolecules or nano-objects) onto predefined regions of a patterned substrate. This is specially interesting in the field of localized surface plasmon resonance (LSPR) biosensors, where transduction only occurs on metallic nanostructures. The aim is thus to ensure that the target molecules can be selectively anchored onto these nanostructures and not adsorbed on the surroun- ding dielectric surface. Thus, we have developped during this PhD different orthogonal functio- nalizations of micro and nanopatterned gold on silica surfaces with thiols and silanes. In regards to the state of the art in this topic, we have proposed a single-step protocol and demonstrated the good orthogonality of such functionalizations by extensive surface chemical characterization including PM-IRRAS, XPS and ToF-SIMS analysis. Furthermore, these functionalizations have been used for the selective anchoring of different latex nanoparticles onto micro and nanopatterns of gold surrounded by silica, as shown by SEM. At the moment, this methodology is being applied in two different photonic devices where we expect on the one hand a coupling between fluorescent nano- beads and plasmonic nano-antennas and, on the other hand, the increase in sensitivity of an LSPR biosensor for detecting different biomolecules.