Poli(p-fenileno de tereftalamida) (PPTA), usualmente chamado de aramida, é uma fibra polimérica de baixa densidade que possui alta rigidez e resistência à tração, assim como excelente estabilidade térmica e química. Essa fibra é utilizada como reforço em materiais compósitos utilizados nas indústrias aeroespacial e automobilística, em artefatos de proteção balística e de proteção ao corte. No entanto, sua aplicação como reforço em materiais compósitos está limitada por sua baixa afinidade interfacial com matrizes poliméricas, devido a sua superfície lisa e relativamente inerte. Para superar esta desvantagem, diversos tratamentos foram desenvolvidos para modificar a superfície da aramida. Contudo, realizar essa modificação sem diminuir a resistência mecânica da fibra é um grande desafio, assim como desenvolver um método industrialmente viável. Líquidos iônicos (LI) apresentam-se como uma alternativa promissora para a compatibilização da aramida com matrizes poliméricas, devido à possibilidade de ajuste de suas propriedades com a escolha de ânions e cátions específicos. Dessa forma, o objetivo deste estudo é investigar a influência de diferentes LI nas propriedades adesivas entre Kevlar e uma resina epoxídica. Para tanto, as fibras foram submetidas a soluções de etanol e LI imidazólicos (cloreto de 1-n-butil-3-metilimidazólio, cloreto de 1-carboximetil-3-metilimidazólio, metanossulfonato de 1-trietilenoglicol monometil éter-3-metilimidazólio e metanossulfonato de 1-n-butil-3-metilimidazólio) e analisadas por espectroscopia do infravermelho, análise termogravimétrica e microscopia eletrônica de varredura. A resistência mecânica das fibras foi investigada por teste de tração e a interface foi caracterizada em termos de molhabilidade e adesão pelos testes de ângulo de contato e pull-out. Os resultados mostraram um aumento na molhabilidade e na adesão nas fibras tratadas com cloreto de 1- n-butil-3-metilimidazólico, metanossulfonato de 1-trietilenoglicol monometil éter-3- metilimidazólio e metanossulfonato de 1-n-butil-3-metilimidazólio. Dois compósitos laminados foram fabricados com os tecidos comercial e tratado com metanossulfonato de 1- trietilenoglicol monometil éter-3-metilimidazólio. Suas propriedades mecânicas foram aferidas por ensaios de tração e short beam. O compósito feito com o tecido tratado apresentou maior resistência mecânica, módulo e tensão de cisalhamento interlaminar. / Poly(p-phenylene terephthalamide) (PPTA), known as aramid, is a low density polymeric fiber that has high rigidity and exceptional tensile strength, as well as excellent thermal and chemical stability. It is used as reinforcement in composite materials in the aerospace and automobile industry and in ballistic and stab-resistant articles. However, its inferior interfacial affinity towards polymeric matrices due to its smooth surface hampers its use in composite materials, preventing full achievement of its potential as reinforcement. To overcome this drawback, various treatments have been applied to modify the aramid surface. Nevertheless it is a great challenge to introduce this modification without diminishing the fiber mechanical properties and to develop an industrially feasible process. Ionic liquids (IL) might be an alternative as compatibilizer in polymeric matrices reinforced with aramid fibers because of their unique set of physical-chemical properties that can be finely tuned by their chemical structures. Hence, the objective of this study is to investigate the influence of different IL on the adhesive properties between Kevlar and epoxy resin. Kevlar fibers were submitted to solutions of ethanol and imidazolium IL (1-n-butyl-3-methylimidazolium chloride, 1- carboxymethyl-3-methylimidazolium chloride, 1-n-hexadecyl-3-methylimidazolium chloride, 1- triethyleneglycol monomethyl ether-3-methylimidazolium methanesulfonate and 1-n-butyl-3- methylimidazolium methanesulfonate) and then analyzed by infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy. The mechanical strength of the fibers was analyzed by tensile strength tests and the interface was characterized by contact angle measurements and pull-out tests. There was an increase in wettability and adhesion of the fibers treated with 1-n-butyl-3-methylimidazolium chloride, 1-triethyleneglycol monomethyl ether-3-methylimidazolium methanesulfonate and 1-n-butyl-3- methylimidazolium methanesulfonate. Two laminated composites were manufactured with commercial and 1-triethyleneglycol monomethyl ether-3-methylimidazolium methanesulfonate treated fabrics and their mechanical properties were measured with tensile strength and short beam test. The composite made with treated fabrics presented higher mechanical resistance, modulus and interfacial shear strength.

Os líquidos iônicos, por geralmente apresentar, em sua estrutura, uma cadeia alquílica apolar e uma parte polar, como o cátion imidazólio, podem ser considerados estruturas anfifílicas, e apresentam semelhanças com os tensoativos. Tais estruturas, devido a este caráter anfifílico, podem interagir com estruturas do tipo Lipossomas ou até mesmo com biomoléculas, como a BSA. Neste trabalho, foram sintetizados três líquidos iônicos inéditos, com rendimentos de 52 a 66%, acoplados a sistemas quirais derivados de aminoácidos naturais e de fácil obtenção, como a L-Cisteína, a L-Serina e a L-Treonina. Estes foram caracterizados tanto do ponto de vista estrutural, quanto por suas propriedades fotofísicas. Como procedimento metodológico utilizou-se de ciclocondensação de aminoácidos, esterificação de Steglich e alquilação para inserção de cadeia carbônica ao anel metil-imidazol. Para investigação e confirmação dessas estruturas utilizou-se de estudos de Ressonância Magnética de 1H e de 13C, Infravermelho, além das espectroscopias de absorção na região do UV-Vis e de emissão de fluorescência. Por fim, estes novos líquidos iônicos foram testados com lipossomas e BSA, cujos resultados mostraram boa interação com essas biomoléculas. / Ionic liquids can be considered as amphiphilic structures and have similarities with the surfactants, once they generally have an apolar alkyl chain and a polar moiety, such as the imidazolium cation. Such structures, due to this amphiphilic character, may interact with liposome structures or even with biomolecules, such as BSA. In this work, three new ionic liquids containing chiral systems derived from naturally occurring amino acids, such as L-Cysteine, L-Serine and L-Threonine were synthesized, with yields ranging from 52 to 66%. They were fully characterized both from the structural point of view, and by its photophysical properties. As methodological procedures, amino acid cyclocondensation, Steglich esterification and alkylation were used. In order to investigate and confirm these structures, magnetic resonance studies of 1H and 13C, infrared, as well as absorption spectroscopies in the UV-Vis region and fluorescence emission were used. At last, these new ionic liquids were tested with liposomes and BSA, and the results showed good interaction with these biomolecules.

No fim do século XX cresceu o interesse por materiais com potencial para aplicação na área da nanotecnologia. Um destes materiais é o grafeno (alótropo do carbono da espessura de um átomo), indicado para aplicações que exploram desde propriedades ópticas até mecânicas. Todavia, os métodos de produção estabelecidos até o momento geram normalmente um produto com alto grau de defeitos estruturais. Por isso, o objetivo deste estudo foi desenvolver um método mais brando para obtenção de grafeno, por meio do desenrolamento de nanotubos de carbono (NTC) de parede múltipla na presença de líquidos iônicos (LI) (que possuem caráter lubrificante e estabilizador) e adicioná-lo à resina epoxídica para avaliar seu efeito nas propriedades do nanocompósito. A metodologia consistiu em definir a rota a que a mistura NTC:LI (bis(trifluorometanosulfonil)imidato de 1-n-butil-3-metilimidazólio – BMImNTf2), na proporção 1:10, deveria ser submetida e depois avaliar variações para validação do método (alteração de temperatura, solventes – LI BMImCl e tolueno e nanocarga – grafite). As misturas de grafeno-NTC/LI produzidas foram adicionadas na proporção de 0,1% em massa de grafeno-NTC à resina epoxídica. A caracterização das misturas se deu pelas técnicas de microscopia eletrônica de transmissão (MET), espectroscopia Raman e microscopia de força atômica (AFM), e dos nanocompósitos, também por microscopia eletrônica de varredura (MEV), análise termogravimétrica (TGA), calorimetria diferencial exploratória (DSC), infravermelho (IV) análise dinâmico-mecânica (DMA) e ensaios mecânicos. A morfologia observada em MET e AFM evidenciou que a rota em que a mistura permaneceu 3 h em aquecimento e agitação magnética sob vácuo e 3 h sob sonificação resultou em grafeno de algumas camadas. Os resultados de Raman mostraram que foi produzido grafeno de boa qualidade, baseando-se na razão ID/IG. Nos nanocompósitos, confirmou-se que BMImNTf2 mantém as folhas de grafeno abertas. Já com BMImCl a morfologia dos NTC permanece inalterada, mas seu grau de emaranhamento é diminuído pela ação lubrificante deste LI, o que reflete em melhoria na resistência ao impacto. Os NTC sem a presença de um LI de forma geral não conferiram melhoria à matriz polimérica (ex: queda de 35% na dureza). / In the late twentieth century, the interest in materials with potential application in the nanotechnology´s field has increased. One of these materials is graphene (carbon allotrope of a single atom thickness), suitable for applications, which exploit properties such as optical or mechanical. However, the methods developed up to now to obtain graphene usually generate a product with high degree of structural defects. Therefore, the aim of this study was to produce graphene sheets through a milder route of unrolling multi-walled carbon nanotubes (CNT) in ionic liquids (IL; which have a lubricating and stabilizing character) and to add it to an epoxy resin to evaluate its effect on the nanocomposite properties. The methodology consisted of defining the route through which the 1:10 mixture of CNT:IL (1-n-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imidate - BMImNTf2) should be submitted, and then evaluate possible variations for validating the method (change in temperature, solvents - toluene and IL BMImCl and nanofiller - graphite). The produced graphene-CNT/IL mixtures were added at 0.1% by weight of graphene-CNT to epoxy resin. Characterization of the graphene/IL mixtures was done by transmission electron microscopy (TEM), Raman spectroscopy and atomic force microscopy (AFM), and the nanocomposites also by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), dynamical mechanical analysis (DMA) and mechanical tests. The morphology observed using TEM and AFM showed that the route based on 3 h under heating, stirring and vacuum, followed by 3 h of sonication leads to CNT unrolling. Raman spectra showed that the produced graphene was of good quality, based on the low ID/IG ratio. In the nanocomposites, CNT unrolling was confirmed when IL BMImNTf2 was used, yielding reasonable property improvements. In the case of IL BMImCl, the unrolling of the CNT did not occur, but the lubricant effect of the IL decreased the degree of entanglement, which increased its impact strength. Differently, the non-treated CNT generally reduced the properties of the polymer matrix, e.g. a 35% drop in hardness.

The first chapter of this thesis introduces the fundamental concepts governing the design and synthesis of supramolecular complexes. By illustrating the synthesis of several coordination cages reported in the literature, the principles underlying the construction of coordination cages by subcomponent self-assembly are elucidated. Ionic liquids are then proposed as solvents for cage systems; general methods for the preparation and synthesis of these solvents are described. The second chapter explores the use of ionic liquids as solvents for existing coordination cages. Potential methods of characterising these cages in ionic liquids are discussed; cages are demonstrated to be stable and capable of encapsulating guests in these ionic environments; and systems in which cages have good solubility in ionic liquids are designed. Building upon these observations, a triphasic sorting system is presented such that each of three different host-guest complexes are soluble in only one of three immiscible liquid phases. In contrast to the static triphasic system described in the second chapter, the third chapter explores directed phase transfer of coordination cages and their cargos from water, across a phase interface, and into an ionic liquid phase. The host-guest complex can then be recycled from the ionic liquid layer back into water after several additional steps. Furthermore, phase transfer of cationic cages is used to separate a mixture of cationic and anionic host-guest complexes. In the fourth chapter, fully reversible phase transfer of coordination cages is developed. Using anion exchange to modulate the solubility of three different cationic cages, reversible transport between water and ethyl acetate is demonstrated. Sequential phase transfer can also be achieved such that, from a mixture of cubic (+16) and tetrahedral (+8) cages, the cubic cage transfers from water to ethyl acetate before the tetrahedral cage. This process is fully reversible; upon the addition of a hydrophilic anion, the tetrahedral cage returns from ethyl acetate to water before the cubic cage.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / The synthesis of two 1-methyl-3-alkylimidazolium tetrafluoroborate (where alkyl = butyl, octyl; [BMIM]BF4 and [OMIM]BF4) based on room temperature ionic liquids (RTIL) is reported. The usefulness of these ionic liquids in organic synyhesis was evaluated through three reactions such as: (i) preparation of the N,N-dimethylenaminones (RCOCH=CHNMe2, where R = Ph, 4-Me-Ph, 4-F-Ph, 4-Cl-Ph, 4-Br-Ph, 4-O2N-Ph, fur-2-yl, tien-2-yl, pyrrol-2-yl, pyrid-2-yl, CH(OMe)2, octyl) from the condensation reaction of N,Ndimethylformamide dimethyl acetal with methylketones; (ii) preparation of the 6-dimethylamino-1,1,1-trifluoro-4-methoxy-3,5-dien-2-one [CF3COCH=CH(OMe)CH=CHNMe2, from the condensation reaction of N,Ndimethylformamide dimethyl acetal with appropriated 1,1,1-trifluoro-4-methoxy-3-penten-2- one and (iii) N-alkylation reaction of 3,5-dimethyl- and 5-trifluoromethyl-3-methyl-1Hpyrazoles, from the reaction of the N-H pyrazoles with alkyl halides (R1 X, where R1 = Bu, octyl, allyl, benzyl, CH₂CH₂CONEt₂). The reaction time, and the yields were investigated and this method showed advantages over the methods described in the literature. / Neste trabalho é relatado a síntese de dois líquidos iônicos, tetrafluorborato de 1-alquil-3-metil imidazolíneo, com alquil = butil, octil ([BMIM]BF4 and [OMIM]BF4) e sua utilização como meios reacionais. A adequabilidade dos líquidos iônicos foi avaliada em três reações: (i) síntese de N,N-dimetilenaminonas (RCOCH=CHNMe2, com R = Ph, 4-Me-Ph, 4-F-Ph, 4-Cl-Ph, 4-Br-Ph, 4-O2N-Ph, fur-2-il, tien-2-il, pirrol-2-il, pirid-2-il, CH(OMe)2, octil) a partir da reação de condensação N,N-dimetilformamida dimetilacetal com metilcetonas; (ii) síntese de 6-dimetilamino-1,1,1-trifluor-4-metoxi-3,5-dien-2-ona [CF3COCH=CH(OMe)CH=CHNMe2, a partir da reação de condensação de N,Ndimetilformamida dimetilacetal com 1,1,1-trifluor-4-metoxi-3-penten-2-ona e (iii) reação de N-alquilação de 3,5-dimetil- and 5-trifluorometil-3-metil-1H-pirazol, a partir da reação de NH pirazóis com haletos de alquila (R¹ X, com R¹ = Bu, octil, alil, benzil, CH₂CH₂CONEt₂). O tempo reacional e os rendimentos foram avaliados e o método mostrou vantagens em relação aos outros métodos descritos na literatura.

The technology employed by human beings for the generation, storage and usage of energy is presently undergoing the fastest and most profound change since the industrial revolution. The changes in the generation and usage of energy necessitate the development of new methods of energy storage. In these systems, electrochemical energy storage will play a crucial role and to this end new electrolytes need to be explored to complement these changes. One such class of liquids is ionic liquids, a class of salts that are molten at room temperature. These liquids have a broad applicability to batteries and supercapacitors. This thesis details work where molecular dynamics simulations have been used to explore the nanostructure of ionic liquids and their mixtures with various molecular solvents at simplistic electrodes. The thesis has two broad sections. The first is covered in Chapter 3, and explores the nanostructure of ionic liquid propylene carbonate solutions, developing a framework through which these nanostructures can be understood. The section concludes that the increasing dilution of ionic liquids decreases the surface charge at which the characteristic ionic liquid oscillatory interfacial structure gives way to a different structure featuring monotonic charge decay. The behaviour of ionic liquids at interfaces is found to be correlated to ion size and type, as well as concentration. A wide divergence in the observed behaviour is shown at positive and negative electrodes due to the asymmetry of propylene carbonate. The second section, consisting of two chapters, explores the interfacial nanostructure of solvate ionic liquids using two different boundary conditions to model the electrode. This work is the first simulation of solvate ionic liquids at electrified interfaces. This section will explore the effect of electrode model on the behaviour of these ionic liquids at the electrode. Chapter 4 uses a fixed charge electrode, whereas Chapter 5 uses one with a fixed potential. The section concludes that regardless of electrode model, the idealised portrait of a solvate ionic liquid - one where the liquid behaves exactly as an aprotic ionic liquid - is not applicable. In Chapter 4's exploration of fixed charged electrodes, the formation of 2 glyme to lithium complexes contradicts the idealised portrait of the liquid. A different change is observed in Chapter 5's exploration of fixed potential electrodes, with both lithium glyme and lithium anion clusters forming at the interface. The key difference between the two studies is that lithium does not coordinate to the electrode in the fixed charge simulations, while in the fixed potential case it does. At the end of Chapter 5 the results are compared against experimental data, with the efficacy of the two models discussed. The aim of both studies is to look at the nanostructure of ionic liquids, when the symmetry between co-ion and cation repulsion - and related effects - is broken by the presence of a non ionic constituent in the liquid.

abstract: This investigation is divided into two portions linked together by the momentous reaches of electrochemistry science, principles influencing everyday phenomena as well as innovative research in the field of energy transformation. The first portion explores the strategies for flue gas carbon dioxide capture and release using electrochemical means. The main focus is in the role thiolates play as reversible strong nucleophiles with the ability to capture CO2 and form thiocarbonates. Carbon dioxide in this form is transported and separated from thiocarbonate through electrochemical oxidation to complete the release portion of this catch-and-release approach. Two testing design systems play a fundamental role in achieving an efficient CO2 catch and release process and were purposely build and adapted for this work. A maximum faradaic efficiency of seventeen percent was attained in the first membrane tests whose analysis is presented in this work. An efficiency close to thirty percent was attained with the membrane cell in recent experiments but have not been included in this manuscript. The second portion of this manuscript studies bulk stress evolution resulting from insertion/extraction of lithium in/from a lithium manganese oxide spinel cathode structure. A cantilever-based testing system uses a sophisticated, high resolution capacitive technique capable of measuring beam deflections of the cathode in the subnanometer scale. Tensile stresses of up to 1.2 MPa are reported during delithiation along with compressive stresses of 1.0 MPa during lithiation. An analysis of irreversible charge loss is attributed to surface passivation phenomena with its associated stresses of formation following patterns of tensile stress evolution. / Dissertation/Thesis / Doctoral Dissertation Materials Science and Engineering 2016

Face à une croissance effrénée de la demande en indium et aux enjeux à la fois socio-économiques et politiques potentiels qu'il représente, le recyclage de l'indium contenu dans les équipements en fin de vie reste la seule alternative pour remédier à des risques de pénuries. Au-delà des aspects économique et stratégique, le recyclage de l'indium peut permettre de préserver l'environnement en évitant l'exploitation à grande échelle des gisements de minerais contenant l'indium. Par ailleurs, la toxicité de l'indium justifie à elle seule le développement de procédés de traitement de déchets en contenant. Pourtant, la récupération de l'indium à partir de déchets électroniques est actuellement assez peu développée, mis à part au Japon, où plusieurs procédés existent à l'échelle industrielle. Ces procédés sont toutefois peu respectueux de l'environnement et fortement énergivores. Dans ce travail de doctorat, le recyclage de l'indium par extraction liquide/liquide dans un liquide ionique suivie de son électrodéposition in situ nous est apparu comme un procédé prometteur, permettant de s'affranchir de l'étape souvent difficile de dés-extraction du cation métallique. Parmi les liquides ioniques que nous avons synthétisés et caractérisés, en termes de structure et de propriétés physico-chimiques, le bis(trifluorométhylsulfonyl) amidure de 1-butyl-1-éthylpipéridinium (BEPipNTf2) s'est avéré le plus adapté du fait de sa bonne stabilité cathodique, de sa faible viscosité, de son caractère hydrophobe et peu hygroscopique. Nous avons montré qu'en synergie avec l'oxyde de trioctylphosphine (TOPO) comme extractant, il est possible d'extraire plus de 90% de l'indium contenu dans une phase aqueuse 10-2 M en HCl. Le système électrochimique In(III)/In(0) dans le BEPipNTf2 a alors été étudié en présence de chlorures, d'eau, d'oxygène et de TOPO, espèces présentes à l'issue de l'étape d'extraction liquide/liquide de l'In(III). Une étude détaillée de l'influence des ions chlorures a notamment été réalisée, mettant en évidence la formation de chlorocomplexes d'indium lors de l'application d'un potentiel cathodique de réduction de l'In(III), ce qui modifie considérablement les caractéristiques électrochimiques du système In(III)/In(0). Les résultats obtenus montrent qu'il est possible d'électrodéposer de l'In(III) sous sa forme métallique dans le domaine de stabilité électrochimique du liquide ionique, et ceci de façon non réversible en présence de TOPO, dont l'électroactivité dans le domaine de potentiel correspondant porte néanmoins à croire que la réduction pourrait entraîner la présence d'impuretés organiques dans le dépôt d'indium et limiter la quantité de métal déposée. / Faced with explosive growth in demand for indium and, faced with challenges to both socio-economic and political potential it represents, the recycling of indium content in the equipments of end of life remains the only alternative to address risk of shortages. Beyond the economic and strategic aspects, recycling of indium can help preserving the environment by preventing large-scale exploitation of mineral ores containing indium. In addition, the toxicity of indium alone justifies the development of methods for treating waste containing indium. However, the recovery of indium from electronic waste is currently fairly limited, except in Japan where there are several processes at an industrial scale. However, these processes are not environmentally friendly and are energy-intensive In this PhD work, recycling of indium by liquid / liquid extraction in an ionic liquid followed by its electrodeposition in situ appeared to us as a promising process, to overcome the often difficult step of de-extraction of the metal cation. Among the ionic liquids that we have synthesized and characterized in terms of structure and of physicochemical properties, 1-butyl-1-ethylpiperidinium bis(trifluoromethylsulfonyl) imide (BEPipNTf2) has been shown most suitable because of its cathodic stability, its low viscosity, its hydrophobic and weakly hygroscopic character. We have shown that in synergy with the trioctylphosphine oxide (TOPO) as extractant, it is possible to extract more than 90% of the indium contained in a 10-2 M HCl aqueous phase. The electrochemical system In(III)/In(0) in the BEPipNTf2 was then studied in the presence of chlorides, of water, of oxygen and of TOPO, which are the species present after the liquid/liquid extraction step of the In(IIII). A detailed study of the influence of chloride ions has been particularly carried out, highlighting the formation of chlorocomplexes of indium when applying a cathodic potential of reduction of In(III), which significantly changes the electrochemical characteristics of the system In(III)/In(0), The results obtained show that indium (III) can be electrodeposited in its metallic form in the range of electrochemical stability of the ionic liquid and that this is non-reversible in presence of TOPO, whose electroactivity in the corresponding potential range suggests that the reduction could result in the presence of organic impurities in the deposition of indium and could limit the amount of metal deposited.

Dans le contexte actuel du développement durable, l'industrie chimique, souvent montrée du doigt par les institutions et le grand public pour son impact négatif sur l'Homme et l'environnement, doit développer des voies de synthèse compétitives et plus éco-compatibles. La préparation d'époxydes à partir d'oléfines représente aujourd'hui un enjeu essentiel du point de vue de la production d'intermédiaires clés pour l'industrie chimique. Basé sur les nombreuses études publiées dans la littérature, ce travail de thèse a eu pour objectif d'étudier le potentiel des liquides ioniques, solvants novateurs aux propriétés uniques, et des ultrasons de puissance, méthode non conventionnelle d'activation, pour l'époxydation d'oléfines catalysée par des porphyrines métallées. Les protocoles expérimentaux de synthèse des liquides ioniques sélectionnés ont été améliorés au regard des principes de la chimie verte et évalués par des indicateurs spécifiques. Ensuite, les mécanismes des réactions d'époxydation ont été mis en évidence grâce à l'utilisation de porphyrines chirales et à l'étude des paramètres sonochimiques en milieu liquide ionique. Finalement, la stabilité des liquides ioniques sous irradiation ultrasonore a été étudiée ; ainsi, leurs produits de dégradation et leurs mécanismes de formation ont été identifiés. / In the current context of sustainable development, the chemical industry, often pointed at by the institutions and the general public for its negative impact on humans and the environment, needs to develop more competitive and more eco-friendly synthetic routes. The preparation of epoxides from olefins is today a critical issue in terms of production of key intermediates for the chemical industry. Based on numerous studies published in the literature, this PhD thesis has aimed at investigating the potential of ionic liquids, innovative solvents with unique properties, and power ultrasound, unconventional method of activation, for the epoxidation of olefins catalyzed by metalloporphyrins. The experimental protocols used for the synthesis of the selected ionic liquids have been improved according to the principles of green chemistry and evaluated by specific indicators. Then, the mechanisms of epoxidation reactions have been evidenced thanks to the use of chiral porphyrins and the study of sonochemical parameters in ionic liquids medium. Finally, the stability of ionic liquids under ultrasonic irradiation has been studied. Their degradation products and their formation mechanisms have been identified.

Depuis les années 1990, l'électronique portable connait un véritable essor. De plus en pluscomplexes, ces appareils requièrent des besoins énergétiques croissants en termes de puissance,d'autonomie et de durée de vie. De nouveaux dispositifs de stockage pouvant être assemblés au plusproche du circuit micro-électronique et dans l'idéal directement sur la puce doivent donc être développés.Les micro-supercondensateurs représentent une solution prometteuse. Constitués principalementd’électrodes en carbone ou oxydes métalliques, leur fabrication sur les puces de micro-électroniques restedifficile. Cette intégration serait facilitée avec des électrodes à base de silicium. L’objectif de cette thèse estl'élaboration de micro-supercondensateurs constitués d’électrodes en silicium nanostructuré. Leursperformances peuvent être améliorées en travaillant à la fois sur les électrodes et sur l’électrolyte.L’électrode doit être stable en présence de l’électrolyte et avoir une grande surface développée.L’électrolyte doit permettre d’atteindre une tension élevée. Ce travail démontre que seules les électrodes ensilicium fortement dopées avec un traitement de surface adapté ont un comportement capacitif. La surfacedes électrodes est augmentée via la croissance de nanostructures par CVD catalysée par de l’or. L’étude del’influence des paramètres de croissance sur la morphologie des nanostructures a permis d’optimiser leprocédé pour obtenir des nano-arbres fortement dopés longs, denses, hyperbranchés et avec plusieursgénérations de branches ont pu être obtenus. L’utilisation du chlorure d’hydrogène permet de contrôlerprécisément le dopage des nanofils. Les paramètres clés des nanostructures pour obtenir de meilleurescapacités ont été identifiés : dopage, longueur, densité, branches. Les performances des microsupercondensateurs(Tension maximale, Energie, Puissance, Stabilité) avec des électrodes en siliciumnanostructurée ont été évaluées dans différents électrolytes. L’utilisation de liquide ionique (EMI-TFSI)permet d’augmenter la tension maximale et donc l’énergie et la puissance. Des pistes d’amélioration ont étéétudiées : traitement de surface, nouvelles architecture de dispositifs. La compatibilité des procédés utilisésavec ceux de micro-électronique a aussi été vérifiée. / Since 1990, portable electronics is a thriving field. Devices gather more and more functions and thusrequire more and more efficient energy sources in terms of power, autonomy and lifespan. Such sourcesshould be fixed as close as possible from the micro-electronic circuit, ideally directly on chip. Microsupercapacitorsare a promising solution. Due to the electrodes materials (carbon or metallic oxide), theirfabrication directly on chip is still difficult. It should be easier with silicon based electrodes. The aim of thiswork is the elaboration of micro-supercapacitors with nanostructured silicon based electrodes. Theirperformances can be improved by working on the electrode and the electrolyte. The electrode must bestable in the electrolyte and have a high developed surface. The electrolyte must lead to high voltage. Thiswork demonstrates that only highly doped silicon electrodes with an adapted surface treatment have acapacitive behavior. The electrode surface can be increased via nanostructures growth of by gold-catalyzedCVD. Thanks to the study of the influence of growth parameters on the nanostructures morphology, theprocess has been optimized to get highly doped, dense, long and hyperbranched nano-trees with severalbranches generations. Their doping level is precisely monitored thanks to the use of HCl. Doping, length,density and branches are the key parameters to improve the electrode capacity. Micro-supercapacitorsperformances (maximum voltage, energy, power, stability) with such electrodes have been evaluated inseveral electrolytes. Higher voltage, and thus higher energy and power can be reached in ionic liquids.Several improvement trails are investigated: surface treatment, new device design. Our processcompatibility with micro-electronics one has been checked.