Este trabalho apresenta a preparação de filmes nanoestruturados de óxido de manganês e de vanádio por diferentes técnicas e a sua caracterização eletroquímica utilizando diferentes líquidos iônicos como eletrólito. Os filmes de óxido de manganês foram preparados por automontagem camada-por-camada e por eletrodeposição assistida por molde de nanoesferas de poliestireno. Os filmes de óxido de vanádio foram preparados também por automontagem camada-por-camada e por deposição eletroforética. Diversos aspectos relacionados ao uso dos líquidos iônicos como eletrólitos foram discutidos: os resultados obtidos para os filmes de óxido de manganês por automontagem camada-por-camada mostraram que os íons do líquido iônico participam do processo de compensação de carga superficialmente e que o cátion do líquido iônico, apesar de mais volumoso, apresenta coeficiente de difusão maior que o Li+, formando uma barreira à intercalação dos mesmos na estrutura do material. A partir dos resultados obtidos para os filmes de óxido de manganês por eletrodeposição assistida por nanoesferas de poliestireno, foi possível verificar que o desempenho do sistema depende da natureza do líquido iônico utilizado, sendo possível obter desempenho superior aos solventes orgânicos convencionais com um dos líquidos iônicos utilizados do ponto de vista da ciclabilidade. Desempenho superior aos eletrólitos convencionais também foi observado para os filmes de óxido de vanádio obtidos por automontagem camada-por-camada. Por fim, a caracterização eletroquímica em líquidos iônicos dos filmes de óxido de vanádio obtidos por deposição eletroforética mostrou que não apenas o uso de nanopartículas, mas também o modo de deposição das mesmas influencia no desempenho eletroquímico do sistema. De maneira geral, os resultados obtidos mostraram que o uso de filmes nanoestruturados e de líquidos iônicos como eletrólitos constituem alternativas promissoras para a obtenção de dispositivos de armazenamento e conversão de energia de alto desempenho e segurança. / This work presents the preparation of manganese and vanadium oxides nanostructured films by different techniques and their electrochemical characterization in different ionic liquids based electrolytes. Manganese oxide films have been prepared by self-assembly layer-by-layer and by electrodeposition assisted by polystyrene nanospheres template. Vanadium oxide films have been also prepared by self-assembly layer-by-layer deposition and by electrophoretic deposition. Several aspects related with the use of ionic liquids as electrolytes have been discussed: the obtained results from layer-by-layer deposition of manganese oxide have shown that ionic liquid ions also participate in the charge compensation process, but only superficially; in spite of ionic liquid cation been larger than Li+, it moves faster, achieving the electrode surface before, being a barrier for Li+ intercalation. From the results obtained for the manganese oxide prepared by template assisted electrodeposition, it was possible to notice that electrochemical performance is dependent on the ionic liquid structure, being possible to achieve higher performance than with conventional organic solvent electrolyte with one of the studied ionic liquid. Superior performance in comparison with conventional electrolyte has also been achieved for vanadium oxide films prepared by layer-by-layer deposition from the point of view of cyclability. Finally, the electrochemical characterization of vanadium oxide films prepared by electrophoretic deposition in ionic liquids has shown that not only the use of nanoparticles but also the deposition method employed influences the electrochemical performance. To conclude, the obtained results have shown that the use of nanostructured films and ionic liquids as electrolytes are promising alternatives for the obtention of high performance energy storage and conversion devices.

A celulose é o biopolímero mais abundante da Terra. Ela contempla muitos dos requisitos desejados para substituição de polímeros sintéticos oriundos de petróleo. Entretanto, a insolubilidade da celulose em água e em solventes orgânicos comuns e a sua decomposição antes da fusão impedem seu processamento por extrusão. Uma solução para esse problema é a preparação de derivados de celulose que possam ser processados por extrusão ou regeneração em não solvente. Nesse ponto, os ésteres de celulose, utilizados há décadas, possuem destaque apresentando grande interesse comercial. Contudo, o contínuo estudo dos ésteres de celulose quanto aos métodos de preparação, de suas propriedades e o desenvolvimento de novos compostos se faz necessário para melhorar e ampliar suas aplicações. Sendo assim, essa tese de doutoramento contribuiu para a química dos ésteres de celulose das seguintes formas: (i) estudo de solventes para síntese de ésteres de celulose em condições reacionais homogêneas; e (ii) síntese, caracterização e moldagem de ésteres mistos de celulose com estrutura controlada. Dentro do primeiro tema, soluções binárias de dimetilsulfóxido (DMSO) e líquidos iônicos (ILs) a base de 1-metilimidazol (acetato de 1-(1-butil)-3-metilimidazólio, C4MeImAc; acetato de 1-(2-metóxietil)-3-metilimidazólio, C3OMeImAc) foram avaliadas como solvente para dissolução e acilação (síntese de acetato de celulose e benzoato de celulose) de celulose sob condições reacionais homogêneas. O foco dessa etapa de trabalho foi verificar se a presença de oxigênio etéreo na cadeia lateral do anel imidazólio favorecia a dissolução e acilação da celulose, uma vez que ele é mais básico que o correspondente grupo metilênico. Surpreendemente, o C4MeImAc apresentou melhor capacidade de dissolução de celulose e os ésteres de celulose nele preparados possuem maior grau de substituição. Para compreensão dessa aparente contradição foram utilizadas as técnicas de reologia; de espectroscopia de 1H e 13C NMR de soluções de celobiose em IL/DMSO; e de solvatocromismo (avaliação da acidez e basicidade de Lewis). Todos essesresultados indicam uma menor interação entre a celulose e o IL contendo cadeia alcóxi e corroboram os dados recém-publicados de cálculos teóricos, que indicam a ciclização, via formação de ligações de hidrogênio intramolecular, do cátion C3OMeIm+. Na tentativa de impedir a ciclização do cátion imidazólio e consequentemente melhorar as propriedades do IL contendo cadeia alcóxi, ILs metilados nas posições 1 e 2 do anel imidazólio foram testados. Apesar de a metilação melhorar a capacidade dos ILs para dissolução e acilação da celulose, não foi observado o efeito esperado para a presença do oxigênio etéreo na cadeia lateral do IL. No segundo tema de estudo, ésteres mistos de celulose (CellCarboxy/Ts) contendo grupo tosilato (com grau de substituição fixo, DSTs ≈ 1,0) e grupos carboxilatos (com grau de substituição variável, DSAcyl) com diferentes hidrofobicidades (acetato, butanoato, hexanoato) foram sintetizados em meio homogêneo de cloreto de lítio/N,N-dimetilacetamida (LiCl/DMAc). A dependência no DSAcyl das propriedades de superfície (polaridade empírica, acidez e basicidade de Lewis; ângulo de contato e energia de superfície) desses ésteres de celulose foi determinada e apresentam correlações simples. Os Cell-Carboxy/Ts também foram caracterizados quanto às suas propriedades térmicas verificando-se que o aquecimento dos ésteres leva à saída dos grupos acila antes do grupo tosilato e que a temperatura de decomposição desses ésteres é menor que a de fusão. Portanto, os Cell-Carboxy/Ts só podem ser moldados por regeneração a partir de soluções. Sendo assim, as técnicas de gotejamento de solução de éster de celulose (solvente acetona) em não solvente (água) e de eletrofiação de solução de Cell-Carboxy/Ts (solvente acetona/DMAc) foram otimizadas para preparação de microesferas e microfibras, respectivamente. As estruturas obtidas apresentaram diâmetro médio de 240 ± 35 nm e 230 ± 20 nm, respectivamente. A aplicabilidade da espectroscopia no infravermelho e no UV-VIS foi avaliada para determinação do DSAcyl dos ésteres mistos obtendo-se resultados satisfatórios. Esses métodos são interessantes, pois permitem a economia de amostra (ca. de 1 % da massa necessária no método tradicional de titulação), o que é relevante em estudos exploratórios de ésteres de celulose onde poucos gramas de amostra são preparados. / Cellulose is most abundant biopolymer in the Earth. It complies with many desired requirements for substitution of petroleum-based polymers. However, cellulose is insoluble in water and common organic solvents and decomposes before undergoes melt flow, which prevents its extrusion processing. One possible solution for this problem is the preparation of cellulose derivatives that can be process by extrusion or by regeneration into non-solvents. In this point, cellulose esters, used for decades, stand out showing great commercial interest. In spite of their long use, the continuous research on cellulose ester focused on new synthetic methods, determination of properties and development of new compounds is necessary to improve and expand their commercial application. Therefore, this PhD thesis contributes to the cellulose esters chemistry in the following way: (i) study of solvents for synthesis of cellulose esters in homogenous reaction conditions (HRC); and (ii) synthesis, characterization and shaping of cellulose mixed esters with controlled structure. In the first approach, binary mixtures of dimethyl sulfoxide (DMSO) and ionic liquids (ILs) based on 1-methylimidazole (1-(1-butyl)-3-methylimidazolium acetate, C4MeImAc; 1-(2-methoxyethyl)-3-methylimidazolium acetate, C3OMeImAc) were evaluated as solvent for cellulose dissolution and acylation (synthesis of cellulose acetate and cellulose benzoate) under HRC. This part of project aim was verify if the presence of ether oxygen on side chain of imidazolium ring can favored the cellulose dissolution and acylation, once it is more basic than the corresponding methylene group. Surprisingly, the C4MeImAc shows higher ability to dissolves cellulose and the biopolymer esters prepared in it have higher degree of substitution. In order to understand this apparent contradiction, were employed the following techniques: rheology, 1H and 13C NMR spectroscopy of celobiose solution in IL/DMSO; and solvatochromism (evaluation of Lewis acidity and basicity). All results indicate a lower interaction between cellulose and the IL with alkoxy side chain and corroborate the recently published data of theoretical calculation which proposed the cyclization of C3OMeIm+ cation, via intramolecular hydrogen bond. In attempt to avoid the imidazolium cation cyclization and consequently improve the properties ofIL containing alkoxy side chain, ILs methylated at positions 1 and 2 of imidazolium cation were tested. Despite methylation improve the IL ability on cellulose dissolution and acylation, the expected effect for the presence of ether oxygen on IL side chain was not observed. In the second part of this study, cellulose mixed esters (CellCarboxy/Ts) containing tosylate unit (fixed degree of substitution, DSTs ≈ 1.0) and carboxylate groups (variable degree of substitution, DSAcyl) with different hydrophobicity (acetate, butanoate, hexanoate) were synthesized in homogeneous medium of lithium chloride/N,N-dimethylacetamide (LiCl/DMAc). The dependence on DSAcyl of surface properties (empical polarity, Lewis acidity and basicity, contact angle, surface energy) of Cell-Carboxy/Ts was determined and show simple correlation. The thermal properties of Cell-Carboxy/Ts were also evaluated verifying that the heating of these cellulose esters promotes the scisson of acetate group before the tosylate ones. Further Cell-Carboxy/Ts decompose before they undergo melt-flow, so these cellulose esters can be shaped only by regeneration from their solution. In this way, Cell-Carboxy/Ts was shaped into microspheres and microfibers using the techniques of dropping (acetone solution into water) and electrospinning (acetone/DMAc solution), respectively. The structures obtained have average diameter of 240 ± 35 nm e 230 ± 20 nm, respectively. The applicability of infrared and UV-VIS spectroscopies to determine the DSAcyl of cellulose mixed esters was evaluated obtaining satisfactory results. These methods are interesting because they use few amount of sample (about 1 % of weight required by traditional titration method). The sample economy is relevant in exploratory studies of cellulose esters since they are carried out on few grams of sample.

O aumento no consumo energético e a crescente preocupação ambiental frente à emissão de gases poluentes criam um apelo mundial favorável para pesquisas de novas tecnologias não poluentes de fontes de energia. Baterias recarregáveis de lítio-ar em solventes não aquosos possuem uma alta densidade de energia teórica (5200 Wh kg-1), o que as tornam promissoras para aplicação em dispositivos estacionários e em veículos elétricos. Entretanto, muitos problemas relacionados ao cátodo necessitam ser contornados para permitir a aplicação desta tecnologia, por exemplo, a baixa reversibilidade das reações, baixa potência e instabilidades dos materiais empregados nos eletrodos e dos solventes eletrolíticos. Assim, neste trabalho um modelo cinético foi empregado para os dados experimentais de espectroscopia de impedância eletroquímica, para a obtenção das constantes cinéticas das etapas elementares do mecanismo da reação de redução de oxigênio (RRO), o que permitiu investigar a influência de parâmetros como o tipo e tamanho de partícula do eletrocatalisador, o papel do solvente utilizado na RRO e compreender melhor as reações ocorridas no cátodo dessa bateria. A investigação inicial se deu com a utilização de sistemas menos complexos como uma folha de platina ou eletrodo de carbono vítreo como eletrodos de trabalho em 1,2-dimetoxietano (DME)/perclorato de lítio (LiClO4). A seguir, sistemas complexos com a presença de nanopartículas de carbono favoreceu o processo de adsorção das moléculas de oxigênio e aumentou ligeiramente (uma ordem de magnitude) a etapa de formação de superóxido de lítio (etapa determinante de reação) quando comparada com os eletrodos de platina e carbono vítreo, atribuída à presença dos grupos laterais mediando à transferência eletrônica para as moléculas de oxigênio. No entanto, foi observada uma rápida passivação da superfície eletrocatalítica através da formação de filmes finos de Li2O2 e Li2CO3 aumentando o sobrepotencial da bateria durante a carga (diferença de potencial entre a carga e descarga > 1 V). Adicionalmente, a incorporação das nanopartículas de platina (Ptnp), ao invés da folha de platina, resultou no aumento da constante cinética da etapa determinante da reação em duas ordens de magnitude, o qual pode ser atribuído a uma mudança das propriedades eletrônicas na banda d metálica em função do tamanho nanométrico das partículas, e estas modificações contribuíram para uma melhor eficiência energética quando comparado ao sistema sem a presença de eletrocatalisador. Entretanto, as Ptnp se mostraram não específicas para a RRO, catalisando as reações de degradação do solvente eletrolítico e diminuindo rapidamente a eficiência energética do dispositivo prático, devido ao acúmulo de material no eletrodo. O emprego de líquido iônico como solvente eletrolítico, ao invés de DME, promoveu uma maior estabilização do intermediário superóxido formado na primeira etapa de transferência eletrônica, devido à interação com os cátions do líquido iônico em solução, o qual resultou em um valor de constante cinética da formação do superóxido de três ordens de magnitude maior que o obtido com o mesmo eletrodo de carbono vítreo em DME, além de diminuir as reações de degradação do solvente. Estes fatores podem contribuir para uma maior potência e ciclabilidade da bateria de lítio-ar operando com líquidos iônicos. / The increasing in energetic consumption and environmental concerning toward rising in the emission of pollutant gases create a favorable scenario to develop non-pollutant technologies and more efficient energy storages. Rechargeable non-aqueous lithium-air batteries possess high theoretical energy density (5200 Wh kg-1), characterizing as a promising system to stationary and electric vehicles applications. However, many issues on the cathode electrode should be addressed to enable this technology, for example, low reversibility of the reactions, low rate-capability and instabilities issues from cathode materials and electrolytic solvents. Here, a kinetic model was employed for modulate the experimental impedance data in order to obtain the rate constants of elementary steps from oxygen reduction reaction (ORR), which allows the investigation of the role of some parameters such as, type and grain size of electrocatalysts, and the solvent influence. The initial investigation were with less complexes systems of platinum bulk or glassy carbon as the working electrode in 1,2-dimethoxyethane (DME)/lithium perchlorate (LiClO4). Based on that, the role of carbon nanoparticles in the ORR was an increasing the oxygen adsorption process, and by slightly increasing (one order of magnitude) the superoxide formation (rate determining step) as when compared with platinum and glassy carbon electrodes due to the presence of side groups acting as mediators to the electron transfer. Nonetheless, a fast surface passivation was observed in function of Li2O2 and Li2CO3 thin films formations, and these films increase the battery overpotential during the charge process (potential difference between charge/discharge >1V). In addition, dispersed platinum nanoparticles (Ptnp) resulted in an increase of two orders of magnitude on the rate constant of the rate determining step when compared to platinum bulk. This can be explained due to changes in electronic properties of metallic d-bands in function of nanometric size. These changes contributed to enhance the energetic efficiency of the practical device when compared to the non-catalyzed system. However, the Ptnp were non-specific toward the ORR catalyzing the electrolyte degradation reactions, and decreasing the energy efficiency faster than the non-catalyzed system. The ionic liquid rather than DME promoted better stabilization process for intermediary superoxide due to interaction between cations present in solution, resulting in an outstanding enhancement of the rate constant for rate determining step (three orders of magnitude) when compared to the same working electrode in DME. In addition, decrease the electrolyte degradation reaction. These factors can improve a higher rate-capability and cycle life of the practical lithium-air batteries.

La formation du duramen est un processus physiologique clé impliqué dans la qualité du bois puisqu'il contribue notamment à sa durabilité naturelle. L'objectif de cette thèse est de comprendre les mécanismes mis en jeu lors de la formation du duramen chez le douglas. L'étude a été menée aux niveaux phénotypiques, biochimiques et moléculaires sur plusieurs génotypes de douglas. Des études phénotypiques, il ressort que la proportion de duramen serait sous influence génétique et très peu environnementale, et que l'expansion du bois de coeur se déroule principalement en automne-hiver. Afin de caractériser la composition biochimique du bois, une nouvelle méthode a été développée. Elle repose sur la dissolution du bois dans des liquides ioniques, les solutions obtenues sont ensuite immuno-marquées à l'aide d'anticorps dirigés contre des épitopes de polymères pariétaux. Cette méthode a permis d'observer l'évolution, cerne par cerne, de la composition pariétale du bois de l'aubier externe au coeur du duramen. Certains polymères sont plus abondants dans l'aubier (arabinanes), tandis que d'autres dans le duramen (pectines, xylanes et galactanes). En parallèle, les gènes impliqués dans la formation du duramen ont été étudiés par RNA-Seq à partir de douglas appartenant à un seul génotype et abattus en hiver. Les résultats montrent que des gènes codant des facteurs de transcription, des protéines de défense, des enzymes de la voie de biosynthèse des phénylpropanoides et des enzymes impliquées dans le remodelage de la paroi sont surexprimés dans la zone de transition par rapport à l'aubier. Des hormones, l'éthylène et le jasmonate notamment, semblent jouer un rôle important dans la maturation de l'aubier. / The heartwood formation is a key physiological process involved in wood quality because it contributes to its natural durability. The goal of this thesis is to understand mechanisms involved in the heartwood formation in douglas fir. This study has been carried out at phenotypic, biochemical and molecular levels from several douglas-fir genotypes. Thanks to phenotypic analysis, we showed that heartwood proportion is probably under genetic control, and little influenced by the environment. In douglas fir, heartwood expansion mainly occurs during autumn and winter. To characterize the biochemical composition of wood, a new method has been developed. The method implies the wood dissolution in ionic liquid, the solution obtained are then analyzed by immunodetection with monoclonal antibodies against plant cell wall glycan epitopes. Thanks to this method, the wood cell wall composition has been studied, ring-by-ring, from the outer sapwood to the inner heartwood. Some polymers are more abundant in the sapwood (arabinans) while others in the heartwood (pectins, xylans and galactans). Then, genes involved in the heartwood formation have been studied by RNA-Seq from trees belonging to one genotype sampled during winter. Results show that genes encoding transcription factors, defence related proteins, enzymes involved in phenylpropanoid biosynthesis and plant cell wall modification are upregulated in transition zone compared to sapwood. Hormones, ethylene and jasmonate especially, seem to play an important role during sapwood maturation.

L'objectif de ce travail est de synthétiser des nanomatériaux de TiO2 pour la dégradation des COV et pour l'élimination des bactéries en surface. Tout d'abord, basé sur une synthèse des matériaux de TiO2 avec la présence d’un liquide ionique BmimPF6 par une voie sol-gel modifiée, les rôles de deux éléments constitutifs de BmimPF6 (P et F) ont été étudiés en faisant remplacer BmimPF6 par des additives contenant P et F. Par rapport à la référence P25 et aux matériaux de TiO2 synthétisés sans additif, le TiO2 synthétisé en présence de P a déjà montré une meilleure cristallinité en phase anatase avant la calcination, et une surface spécifique élevée et une petite taille moyenne des cristaux étaient maintenus même après calcination. Ces propriétés étaient similaires aux échantillons TiO2 synthétisés en présence de BmimPF6; Tandis que les cristaux de TiO2 en présence de F ont montré une forme anisotrope pendant le murissement de la synthèse. Les évaluations de l'activité photocatalytique des photocatalyseurs ont ensuite été réalisées. Par rapport au TiO2 synthétisé sans additif et au TiO2 P25, les matériaux de TiO2 à faible teneur en P et F ("PANaF") ont présenté une activité plus élevée sous irradiation UVA à la dégradation d'un COV modèle, Méthyléthylcétone (MEK) en phase gazeuse. Le même matériau a également montré une activité anti-bactérienne en surface plus élevée sous UVA contre plusieurs souches de différentes espèces bactériennes dans liquide par rapport à celles de P25. Une corrélation entre la performance photocatalytique élevée et les propriétés des matériaux pour TiO2 "PANaF" a été finalement proposée. Les influences de la présence de PO43- en bulk ou en surface de TiO2, de la concentration d’O2 dissous dans le milieu et de la topologie de surface des photocatalyseurs sur l'activité photocatalytique éteint également sujets de discussion. Le produit "PANaF" présente un intérêt pour l'élaboration industrielle à cause des réactifs pas cher et son performance élevée. / The objective of this work consists in synthesizing TiO2 nanomaterials designed for the degradation of VOCs and for the elimination of bacteria on surface. Firstly, based on a synthesis of a BmimPF6-ionic liquid-derived TiO2 material through a modified sol-gel route, the roles of two constituent elements of BmimPF6 (P and F) have been investigated by replacing BmimPF6 with P- and F- contained additives. Comparing to the reference P25 and additive-free-derived TiO2 materials, P-derived TiO2 showed already well crystallized anatase phase before calcination and a high surface area along with a small mean crystal size even after calcinations. Those properties were similar to that synthesized with the presence of BmimPF6; while F-derived TiO2 crystals showed anisotropic shape during the aging step of the synthesis. Evaluation of the photocatalytic activity of the photocatalysts has been performed then. Compared to additive-free derived TiO2 and the TiO2 P25, P- and F- derived TiO2 materials with low P and F content (“PANaF”) showed higher activity under UVA in terms of gas-phase degradation of a model VOC, Methl Ethyl Ketone (MEK). The same material also showed higher surface anti-bacterial activity under UVA in liquid against several strains of different bacterial species over that of P25. A correlation between the high photocatalytic performances with the material properties for “PANaF” TiO2 materials was finally proposed. The influences of the presence of bulk or surface PO43-, dissolved O2 concentration and surface topology on photocatalytic activity were also discussed. The cheap replacement additives used and the resulted high activity of “PANaF” TiO2 nanomaterials presents interest for industrial elaboration.

Abstract Decreasing oil reserves, the need to reduce CO2 emissions and increasing energy demand are issues that are forcing scientists to search for new opportunities in the field of energy. As a result, biofuels have been considered as one possible solution to solve part of these challenges. This research is one small part of that effort. For both human and economic reasons the use of edible raw materials for biofuel production is not sustainable. This study aims to convert forest industry waste, namely fibre sludge, into reducing sugars (glucose). This platform chemical can then be converted to value-added products, biofuels such as ethanol or butanol for example. Depolymerisation of fibre sludge (cellulose) to glucose monomers was performed firstly by pretreatment with ionic liquids [BMIM]Cl and [AMIM]Cl and secondly hydrolysed by acids (dilute maleic and sulphuric acids) and enzymes. To go further with the research the two pretreatment steps, dissolution and hydrolysis were combined into a one-step reaction by using a task-specific ionic liquid [SBMIM]Cl. With the ionic liquid [AMIM]Cl used for pretreatment in this study, we were able to recover 85% of sugars relative to the initial dry mass of the fibre sludge. Corresponding yield was about 30% without pretreatment. The task-specific ionic liquid [SBMIM]Cl was able to dissolve and hydrolyse fibre sludge in a one-step reaction. This ionic liquid was also able to dissolve wet fibre sludge with a moisture content of up to 50%. Enzymatic hydrolysis of [AMIM]Cl pretreated fibre sludge showed also very promising yields of reducing sugars. / Tiivistelmä Biotaloudessa keskeisiä globaaleja haasteita ovat kasvava energiantarve, vähenevät fossiiliset öljyvarannot sekä tarve vähentää energiantuotannon ja liikenteen hiilidioksidipäästöjä, mikä on lisännyt viime vuosina aktiivisuutta biopolttoainetutkimuksen saralla. Biopolttoaineet voidaankin nähdä eräänä mahdollisuutena lisätä uusiutuvien luonnonvarojen käyttöä sekä siten edistää vähähiilistä taloutta. Uusien kestävän kehityksen periaatteita noudattavien energiantuotantomenetelmien kehittämisessä on suosittava biomassoja, jotka eivät kilpaile ruoantuotannon kanssa samoista raaka-aineista. Tässä suhteessa erityisen keskeisessä asemassa ovat mm. teollisuuden sivutuotteet, joita myös tässä työssä on tutkittu. Väitöskirjatutkimuksessa biomassaraaka-aineena on käytetty selluteollisuuden sivutuotteita, erityisesti kuitulietettä. Kuitulietteessä on korkea selluloosa- ja hemiselluloosapitoisuus, minkä vuoksi se soveltuisi ns. platform-kemikaalien valmistuksen raaka-aineeksi ja edelleen arvokkaiden kemikaalien ja polttoaineiden valmistukseen. Tutkimuksessa tavoitteena on ollut kuitulietteen sisältämien polymeerien liuottaminen ja hydrolyysi pelkistyneiksi sokereiksi, erityisesti glukoosiksi, mahdollisimman korkealla saannolla. Kuitulietteen, kuten yleensäkin selluloosan, haasteena on sen niukkaliukoisuus perinteisiin liuottimiin. Tämän vuoksi kuitulietettä esikäsiteltiin ionisissa liuottimissa ([BMIM]Cl ja [AMIM]Cl), jotta depolymerisaatio glukoosimonomeereiksi olisi mahdollinen korkealla saannolla. Esikäsittelyn jälkeen hydrolyysi tehtiin joko laimealla hapolla tai entsymaattisesti. Esikäsittelyä tutkittiin myös ns. spesifisessä ionisessa liuottimessa ([SBMIM]Cl), jossa kuitulietteen liukeneminen ja hydrolyysi tapahtuivat yhdessä vaiheessa. Esikäsittely [AMIM]Cl:ssa mahdollisti sen, että alkuperäisen kuivan kuitulietteen sokereista saatiin talteen 85 % entsymaattisen hydrolyysin jälkeen. Ilman esikäsittelyä vastaava saanto oli noin 30 %. Ionineste, [SBMIM]Cl, onnistui liuottamaan ja hydrolysoimaan kuitulietteen yhdessä vaiheessa, tosin sokerisaannot jäivät alhaisiksi. Märkä kuituliete, jonka kosteuspitoisuus oli 50 %, liukeni myös tähän ioninesteeseen.

Ce travail décrit une méthodologie de synthèse pallado-catalysée en milieu liquide ionique [BMIM][BF4] en utilisant des ligands phosphines et polyphosphines pour les réactions d’alcynylation d’arènes et méthoxylation des alcynes. La première partie de ce mémoire est consacrée à une synthèse et une discussion sur l’aspect « chimie durable » des liquides ioniques en particuliers les sels d’imidazoliums, leur synthèse, et leurs propriétés physico-chimiques. La deuxième partie, concerne un rappel bibliographique sur les réactions de couplage carbone-carbone catalysées par les métaux de transition et en particuliers le palladium en milieu liquide ionique. Dans la troisième partie sont présentés les résultats catalytiques obtenus dans le cas des couplages de bromo et chloroarènes et hétéroarènes avec des alcynes terminaux en milieu [BMIM][BF4]. La quatrième partie est consacrée à la synthèse de ligands originaux de type triphosphines et à la réaction d’alkoxylation catalysée par leurs complexes de palladium en milieu [BMIM][BF4]. / The properties of the ionic liquids such as their low melting point, their non-volatility, their thermal stability, and specially their ability to solubilize organic and inorganic compounds, made of them an interest media for organic synthesis. During this work, two principal research orientations were make it with the aim of the development of an efficient and immobilized palladium catalytic system which opens the way to recycling or continuous flow chemistry. The first part of this work was the study of the Heck alkynylation in [BMIM][BF4], using the system palladium monophosphines (PPh3 or imidazolium monophosphines) to make the coupling of a variety of activated and deactivated bromides and chlorides substrates with different terminal alkyne and diyne. The second part of this work was dedicated to the synthesis of new tiphophines ligand and their palladium complexes and the study of their potential in the methoxylation reaction in [BMIM][BF4].

Les batteries lithium-ion dominent le marché des appareils nomades et celui des véhicules électriques. Néanmoins elles posent des problèmes de sécurité liés à leur électrolyte, contenant des carbonates inflammables et volatils. Pour sécuriser ces systèmes, les liquides ioniques (LI) sont étudiés comme électrolytes alternatifs. Ce sont des sels liquides à température ambiante, réputés stables thermiquement et non inflammables. Ce caractère sécuritaire des LI, souvent avancé, est pourtant peu étayé par des expériences probantes. Les travaux de cette thèse visent à comprendre le comportement de ces LI en situations abusives, telles qu'un échauffement de la batterie, un feu ou une surcharge. Les températures de décomposition de LI contenant les cations imidazolium ou pyrrolidinium différemment substitués et l'anion bis(trifluoromethanesulfonyl)imide ont été déterminées par analyse thermogravimétrique (ATG). Une analyse critique des données (de la littérature et de nos mesures) a permis de définir une procédure optimisée, pour obtenir des résultats reproductibles et comparables. Des électrolytes constitués de mélanges de carbonates ou de LI et de sels de lithium ont été analysés par ATG dynamique et isotherme, et leurs produits de décomposition ont été identifiés. Leur comportement au feu a été testé par la mesure des chaleurs de combustion, des délais d'inflammation et l'identification des gaz générés. Des tests de cyclage électrochimique ont été menés avec ces mêmes électrolytes dans des systèmes lithium-ion constitués des électrodes Li4Ti5O12 et LiNi1/3Mn1/3Co1/3O2. L'évolution des électrolytes et des surfaces des électrodes en situation de surcharge a été examinée / Lithium-ion batteries are dominating both the nomad device and electric vehicle markets. However they raise safety concerns related to their electrolyte, which consists of flammable and volatile carbonate mixtures and toxic salts. The replacement of the latter by ionic liquids (IL), liquid salts claimed to be thermally stable and non-flammable, could provide a safer alternative. Yet this often claimed feature has been poorly examined by experiments. The work of this thesis investigates IL behaviour under abuse conditions such as overheating, fire or overcharge. Decomposition temperatures of IL based on differently substituted imidazolium or pyrrolidinium cations and the bis(trifluoromethanesulfonyl)imide anion were determined by thermogravimetric analysis (TGA). A critical study of gathered data (from literature and our work) led to the determination of an optimised procedure to obtain reproducible and comparable results. Electrolytes based on carbonates mixtures or IL and containing lithium salt were studied by dynamic and isothermal TGA, and their decomposition products were identified. Their combustion behaviour was also tested by measuring heats of combustion and ignition delays. Emitted gases were analysed and quantified. Electrochemical cycling tests were carried out with these electrolytes in lithium-ion systems based on Li4Ti5O12 and LiNi1/3Mn1/3Co1/3O2 electrodes. The evolution of the electrolytes and electrodes surface was also examined under overcharge

Orientador: Fabio Augusto / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-27T10:01:00Z (GMT). No. of bitstreams: 1 Sampaio_BrunaReginadeToledo_M.pdf: 17858649 bytes, checksum: c23714f1f5bd4e3d6e831f6705306053 (MD5) Previous issue date: 2015 / Resumo: Nesta dissertação é descrita duas novas abordagens para microextração em fase sólida. A primeira delas tem como objetivo aumentar a massa extraída já que a mesma é limitada pelo reduzido volume da fase extratora. Para isso, foi proposto o desenvolvimento de um dispositivo, no qual ocorre a compartimentalização do processo de dessorção dos analitos da matriz e a sorção dos mesmos pela fibra de SPME. Dessa forma é possível operar simultaneamente nas temperaturas ótimas de cada processo. O processo de extração ocorre no modo headspace dinâmico, no qual um gás de purga é percolado pela matriz, tornando-se saturado pelos analitos. Este gás transporta os analitos para o interior do dispositivo onde os mesmos serão extraídos pela fibra de SPME resfriada. Esse resfriamento é necessário pois a sorção do analitos pela fibra é um processo exotérmico. Já a segunda abordagem propõe a confecção de novas fibras sortivas baseadas em polímeros iônicos líquidos com o intuito de expandir a aplicabilidade da SPME pois comercialmente, a quantidade de fibras disponíveis é bastante limitada, principalmente no que se refere à extração de analitos polares. Nesta abordagem foi possível a criação de uma nova rota para confecção de fibras baseadas em polímeros iônicos líquidos empregando-se nitinol como suporte, o que promoveu maior resistência e durabilidade para a fibra. Estas novas fibras apresentaram precisões com valores de desvio padrão relativo em torno de 15% e robustez em condições severas de extração; tais fibras foram aplicadas, para prova de conceito, em um estudo de detecção e quantificação de adulteração em café / Abstract: This thesis describes two new approaches to solid-phase microextraction (SPME). The first aims to increase the extracted mass since, which is limited by the small volume of the extraction phase. In this context, it is proposed the development of a device that compartmentalizes the desorption of the analytes from the matrix to the headspace and their sorption by the SPME fiber. This setup allows the simultaneous operation of each process at their optimum temperatures. The extraction process takes place in the dynamic headspace where a inert purge gas is percolated through sample matrix, becoming saturated with the analytes. This gas, then, transports the analytes to the device where they will be sorbet by cold SPME fiber. This cooling is necessary since the sorption of analytes by the fiber is an exothermic process. The second approach proposes the development of new sorbent coatings based on polymeric ionic liquids. It was possible to create a new route for manufacturing nitinol-based SPME fibers coated with PIL providing greater strength and durability of the fiber. These new fibers showed precision with relative standard deviations below 15% and robustness in harsh conditions of extraction / Mestrado / Quimica Analitica / Mestre em Química

This thesis deals with ionic liquids and use of ionic liquids as electrolytes in lithium-ion batteries. Thesis describes basic characteristics of secondary electrochemical cells and characteristics of ionic liquids. Thesis also describes modifications and measurement of ionic liquids. Thesis also presents the results of measurement conductivity and potential window of modified ionic liquids.