Le glycérol et le fructose sont des molécules qui peuvent être extraites facilement de labiomasse et en des quantités substantielles. Ce travail de recherche porte sur la déshydratationcomme moyen de valoriser ces composés. C’est dans ce but que des catalyseurs supportés suroxydes de zirconium et de titane, ainsi que des matériaux de type phosphate de calcium, ontété préparés et testés pour la réaction de déshydratation du glycérol en phase gazeuse. Desoxydes mixtes de niobium et cerium ainsi que des oxydes mixtes mésoporeux de Nb2O5-MeO2 (M = Ce, Zr, Ti) ont été également préparés et cette fois-ci testés pour la réaction dedéshydratation du fructose en milieu aqueux. Dans les deux cas, les propriétés acido-basiquesde surface des catalyseurs étudiés ont été corrélées à leur efficacité catalytique. / Glycerol and fructose are molecules that are readily available in substantial quantities fromthe biomass. In this work dehydration routes for valorization of these compounds wereinvestigated. Therefore, zirconia and titania based catalysts, and calcium phosphate materialswere prepared and evaluated in the glycerol dehydration in gas phase. Niobia-ceria mixedoxides and mesoporous Nb2O5-MeO2 (M = Ce, Zr, Ti) mixed oxides were prepared andtested in fructose dehydration reaction in aqueous phase. The surface acid-base properties ofthe studied catalysts were correlated to their catalytic performance.

La déshydratation du glycérol en acroléine a été étudiée sur de nouveaux catalyseurs à base d'oxydes en vue de mettre au point un nouveau procédé de production de la méthionine. Ces catalyseurs performants sont des zircones niobiées et des zircones tungstées dopées à la silice. Si les catalyseurs proposés dans la littérature jusqu'à présent pouvaient être sélectifs, ils se désactivaient rapidement par cokage. Les nouveaux catalyseurs mis au point sont aussi actifs et sélectifs mais beaucoup plus stables sous flux réactionnel. Les performances des zircones niobiées sont très sensibles à la méthode de préparation; les catalyseurs ont été caractérisés par DRX, spectroscopie Raman, MET, EDX, XPS. Ces analyses ont montré qu'une partie du niobium est incorporée dans la zircone qui est recouverte d'espèces polymères de niobium. Les zircones tungstées performantes sont constituées d'une zircone recouverte de silice et de polytunsgtates. L'acido-basicité des catalyseurs a été étudiée par différentes techniques: réactions modèles de transformation du méthylbutynol et du 2-propanol, TPD-NH3, adsorption de NH3 et SO2étudiée par microcalorimétrie et adsorption de pyridine suivie par IR. Ces études ont permis de montrer que les sites basiques de la zircone sont néfastes pour les performances et que les sites acides de Brönsted avec une large gamme de force acide sont actifs et sélectifs en acroléine. Nous avons montré par microcalorimétrie que même les sites acides très faibles participent à la réaction / Glycerol dehydration to acrolein has been studied over innovative oxide catalysts in order to develop a new methionine production process. These performing catalysts are niobiate zirconia mixed oxides and tungstated zirconia doped with silicium. The catalysts proposed so far in the literature are active and selective but they show fast deactivation under reaction flow due to coke deposition. The new catalysts appear at least as active and selective but much more stable. The niobiate zirconia mixed oxides, which catalytic performances are very sensitive to the preparation method, have been characterized by XRD, Raman spectroscopy, TEM with EDX analyses and XPS. Theses analyses show that niobium cations are partially incorporated into zirconia and covered its surface as polymeric niobium oxide species. The efficient tungstated zirconia catalysts consist of zirconia cover with silicium and polymeric tungstate species. Acid-base properties of the catalysts have been studied by model reaction of methylbutynol and 2-propanol, NH3-TPD, SO2 and NH3adsorption followed by microcalorimetry and IR spectroscopy of pyridine adsorption. These studies show that the zirconia uncovered by silica or containing no niobium are unselective sites and that Brönsted acid sites of the polymeric tungstate or niobium oxide species are the selective sites in acrolein. The strength of these sites does not appear as a key parameter to acrolein selectivity and even weak sites participate to the reaction

La valorisation de la biomasse est une alternative intéressante aux ressources fossiles, et s'effectue fréquemment en catalyse hétérogène. L'élaboration de nouveaux catalyseurs est une tâche ardue qui peut être considérablement accélérée in silico. Cependant les molécules de la biomasse sont souvent complexes et hautement oxygénées, rendant ainsi les calculs plus difficiles et couteux en temps. Parmi ces composés, les polyols sont particulièrement importants. Nous avons développé des relations du type Brønsted-Evans-Polanyi (BEP) à partir d'une étude DFT menée sur une famille de monoalcools concernant les dissociations des liaisons C-H et O-H sur des catalyseurs métalliques (Co, Ni, Ru, Rh, Pd, Ir, Pt). Ces relations ont pour but de prédire l’énergie d’activation d’une étape élémentaire à partir de son énergie de réaction. La précision obtenue par ces modèles linéaires est supérieure à 0.10 eV pour l'échantillon considéré. Ces relations ont ensuite étaient appliquées aux étapes élémentaires de la déshydrogénation du glycérol, choisi comme polyol prototype. On observe une erreur moyenne inférieure à 0.10 eV et une erreur systématique de l'ordre de ± 0.10 eV sur Rh. Etant donné que la principale différence entre les monoalcools et le glycérol, vient des liaisons H intramoléculaires présentes dans celui-ci, nous avons mis en place des relations linéaires pour prédire la déshydrogénation des monoalcools assistée par l'eau. Ces nouvelles relations nous ont permis d'améliorer la prédiction sur le glycérol et même d'éliminer la déviation systématique dans le cas de la rupture de la liaison OH. Même si dans cette étude nous nous sommes focalisés sur la déshydrogénation du glycérol, des méthodes similaires pourraient être appliquées à d'autres polyols avec d'autres réactions chimiques, accélérant ainsi considérablement la recherche in silico de catalyseurs solides. Ce travail pave la route pour le développement de nouvelles techniques numériques pour aborder la question de la conversion de la biomasse. / Biomass valorization is an interesting alternative to fossil resources, which is frequently performed via heterogeneous catalysis. Designing new catalysts is a challenging task that can be significantly accelerated in silico. However, biomass molecules are often complex and highly oxygenated, hence rendering calculations more difficult and time consuming. Among these compounds, polyols are particularly important. We developed linear relations of the Brønsted-Evans-Polanyi (BEP) type from the DFT study of C-H or O-H bond dissociation elementary steps for a family of monoalcohol molecules on metallic catalysts (Co, Ni, Ru, Rh, Pd, Ir, Pt). Such relations aim at predicting activation energies from reaction energies. The accuracy of the obtained linear energy models is better than 0.10 eV on the sampling set. Then, the relations were applied for the prediction of the dehydrogenation elementary steps of glycerol, chosen as a prototype of polyalcohols, with an accuracy better than 0.10 eV and with a systematic error around ±0.10 eV for Rh. Keeping in mind that the main difference between glycerol and monoalcohols comes from intramolecular H-bonds present in the former, we designed linear relations for water-assisted dehydrogenation of monoalcohols. These new relations allowed us to improve the prediction on glycerol and to eliminate the systematic deviation in the case of OH bond breaking. Even if in this study we focused on glycerol dehydrogenation, similar methods may be applied to other polyols with other chemical reactions, and considerably speed up the computational design of solid catalysts. This work paves the way for the development of novel numerical techniques to address the issue of biomass conversion.

Ces dernières années, la notion de Développement Durable a bouleversé la recherche académique etindustrielle dans le domaine de la chimie. L’utilisation de matières premières issues des ressources renouvelables en constitue l’un des aspects les plus marquants. De même, le développement de procédés originaux, qui s’appuient sur des systèmes catalytiques recyclables, des transformations chimiques innovantes et de nouveaux solvants plus respectueux de l’environnement font l’objet d’un intérêt croissant, en raison des gains environnementaux et économiques. Les travaux de recherche décrits dans cette thèse s’inscrivent dans ce contexte et présentent la mise au point de nouvelles voies d’accès aux éthers de glycérol, des molécules à haute valeur ajoutée. Plusieurs procédés originaux ont été développés en utilisant le glycérol comme substrat biosourcé issu de l’industrie oléo-chimique. Ainsi, l’alkylation réductrice d’acides carboxyliques avec le glycérol en présence de palladium sur charbon et d’une résine acide a permis de préparer une variété de 1-Oalkyléthersde glycérol. Une procédure alternative a été développée à partir des huiles végétales et des esters méthyliques, par transestérification puis réduction de l’ester intermédiaire sous hydrogénation catalytique. Ensuite, un procédé d’alkylation déshydrogénante de dérivés de la cyclohexanone avec le glycérol a donné un nouvel accès aux 1-O-aryléthers de glycérol et a été étendu aux éthers et aux amines aromatiques. Enfin, de nouveaux solvants aprotiques dérivés du glycérol ont été synthétisés par une catalyse de transfert de phase. En particulier, la toxicité du 1,2,3-triméthoxypropane ainsi que son utilisation dans des transformations chimiques comme nouveau solvant ont été évaluées. / In recent years, sustainable development brought unprecedented changes in industrial and academic researches. The use of raw materials from renewable resources is one of the most outstanding aspects of these changes. The development of original processes, with recyclable catalytic systems, new chemical transformations as well as new solvents with a lower environmental impact are of growing interest, because of environmental and economical profits. The research work described in this thesisis focused on the development of new accesses to glyceryl ethers as high value added coumpounds.Thus, several processes were developed by using glycerol as accessible and bio-based starting material from the oleochemical industry. First, we found a benign and eco-friendly process for the synthesis of1-O-alkyl glyceryl ethers by catalytic reductive alkylation of carboxylic acids with a recyclable catalytic system associating palladium on carbon and an acid ion exchange resin. A second two steps procedure was also developed when starting from a vegetable oil or a methyl ester, which was transesterified to the corresponding monoglyceride followed by its reduction by catalytic hydrogenation. We report also a straight forward and palladium catalyzed dehydrogenative alkylation of cyclohexanone derivatives with alcohols, including glycerol, and amines in order to prepare avariety or aryl ethers and aryl amines. Finally, we prepared new aprotic and glycerol-based solvents bya solvent-free phase-transfer catalysis. In particular, the toxicity of 1,2,3-trimethoxypropane and its utilization as alternative solvent in chemical transformations was evaluated.

L’objectif de cette thèse consiste à mettre en place un système d’émulsion catalysé par des nanoparticules de Pickering afin de synthétiser des tensioactifs bio sourcés. Pour cela nous nous sommes intéressés à des matériaux mésoporeux fonctionnalisés (de type MCM-41). Ces matériaux favorisent la formation des émulsions tout en catalysant la réaction.Après une étude bibliographique sur le glycérol, les tensioactifs, les émulsions de Pickering et les matériaux mésoporeux, nous nous sommes intéressés à la synthèse et à la fonctionnalisation de ces matériaux. Puis après les avoir caractérisés, nous les avons testés dans des réactions modèles biphasiques (acétalysation et hydrolyse d’ester). Enfin, nous avons terminé cette étude en testant ces catalyseurs dans notre réaction cible (éthérification du glycérol par des alcools gras). La MCM-41 a été synthétisée en utilisant un chauffage micro-onde.Les fonctions greffées sur nos matériaux ont permis de faire varier la balance hydrophile hydrophobe de nos matériaux tout en leur fournissant une fonction catalytique. Les nanoparticules ont été caractérisées par leur ATG, BET, DRX, analyse élémentaire, acidité et tailles des particules.Des catalyseurs à base d’Aerosil® 200 et de Nanoparticules de carbone ont également été testés.Une longue chaine alkyke (C18) et des nanoparticules de petites tailles (Aerosil® 200 et nanoparticules de carbone) favorisent la stabilité des émulsions. Cependant la présence de pores dans nos matériaux n’apporte pas d’avantage catalytique déterminant. / The objective of this work is the conception of emulsion catalysed by Pickering nanoparticles inorder to synthetize biosurfactant. Our strategy was based on functionalised mesoporous materials(MCM-41). These materials combine both emulsion stabilisation and reaction catalysis.After a bibliographic study on glycerol, surfactants, Pickering emulsions and mesoporousmaterials; our strategy was to functionalise these materials. After charaterisation, these materialswere tested in bipohasic model reactions (acetalysation and ester hydrolysis). We come to the end of this study by testing these catalysts in our target reaction (glycerol etherifaction from fattyalcohol).The MCM-41 was synthetized by using a microwave heating. The grafted functions on our materials can both make several hydrophilic-hydrophobic materialsas possible and provided them some catalytic functions. The nanoparticles were characterized byTGA, BET, XRD, elemental analysis, acidity and particle size.Catalyst from Aerosil® 200 and carbon nanoparticles were also tested. A long alkyl chain (C18) and small nanoparticles (Aerosil® 200 and carbon nanoparticles) supportthe emulsion’s stability. Nevertheless, the porous inside our materials is not interesting on acatalytic point of view.

Camundongos Swiss, quando submetidos à dieta hiperlipídica (HL), apresentam considerável ganho ponderal e de depósitos adiposos, tornando-se obesos e resistentes à insulina. O objetivo deste trabalho foi avaliar o efeito da dieta HL por 8 semanas no perfil inflamatório, síntese de triacilglicerol (TAG) com ênfase na vias de geração de glicerol-3-fosfato (G3P) e lipólise nos tecidos adiposos brancos (TAB) retroperitoneal (RETRO) e epididimal (EPI) de camundongos. Camundongos Swiss foram alimentados com as dietas: controle (CT) - dieta purificada (AIN-93G); ou HL - dieta AIN-93G modificada contendo 35% de lipídeos (4% de óleo de soja e 31% de gordura suína). Os camundongos alimentados com a dieta HL apresentaram uma maior massa corporal, acompanhada pelo aumento nos tecidos RETRO e EPI, além de desenvolverem resistência à insulina constatada no teste de tolerância à glicose (TTG), hiperglicemia e hiperinsulinemia. O conteúdo protéico da pAKT, avaliado por western blot (WB), e a adiponectina, dosada em homogenados dos tecidos adiposos, estão reduzidos apenas no EPI. Houve aumento na expressão gênica de MCP-1 e PAI-1, e foi observada menor área dos adipócitos no EPI, sem alteração no RETRO dos animais HL. A síntese de novo de ácidos graxos (AG), avaliada pela incorporação de 3H de 3H2O em AG foi maior em ambos os TAB, porém a captação de AG das lipoproteínas circulantes avaliada pela atividade e expressão da lipase lipoproteica (LPL) aumentou no EPI e reduziu no RETRO. A dieta HL induziu aumento na fosforilação do glicerol, avaliada pela atividade e conteúdo da GK que aumentaram nos dois TAB, e maior incorporação de 1-14C-glicerol em TAG no EPI. A captação de glicose in vitro e conteúdo do GLUT- 4, que indicam atividade da via glicolítica foram reduzidos no EPI e RETRO, assim como a gliceroneogênese avaliada pela incorporação de 1-14C-piruvato em TAG, sem alterações na atividade e conteúdo da fosfoenolpiruvato carboxiquinase (PEPCK). A atividade lipolítica basal foi avaliada in vitro pela liberação de glicerol por adipócitos isolados, e não foi alterada pela ingestão de dieta HL, porém quando estimulada por noradrenalina a liberação de glicerol foi menor nos animais HL, assim como as fosforilações da ATGL e HSL e conteúdo do receptor adrenérgico ?3. A dieta HL levou a uma redução no conteúdo de PPAR? e aumento de ATF3 em ambos os tecidos. No EPI houve aumento de pCREB, pSTAT3 e RGS2 em relação aos controles enquanto no RETRO a única diferença encontrada foi a menor pSTAT3. Nossos resultados demonstram que o aumento nos TAB é resultado de maior síntese e captação de AG, e que o G3P necessário para a esterificação a TAG é proveniente principalmente da fosforilação direta do glicerol pela GK; além disso, a reduzida lipólise também parece contribuir para esse quadro. Nos animais HL, o EPI parece ser mais propenso aos efeitos da dieta do que o RETRO / Swiss mice when subjected to high fat diet (HFD), shown considerable weight gain and adipose depots, becoming obese and insulin resistant. The aim of this study was to evaluate the effect of HFD diet for 8 weeks in the inflammatory profile, triacylglycerol (TAG) synthesis with emphasis in glycerol-3-phosphate (G3P) generation pathways and lipolysis in retroperitoneal (RETRO) and epididymal (EPI) white adipose tissue (WAT) of mice. Swiss mice were fed with diets: control (CT) - purified diet (AIN-93G); or HFD - purified diet (AIN-93G) plus 35% of fat (4% soybean oil and 31% of lard). Mice fed a HFD diet had a higher body mass, accompanied by an increase in RETRO and EPI tissues, in addition to developing insulin resistance, evidenced by glucose tolerance test (GTT), hyperglycemia and hyperinsulinemia. The protein content of pAKT, accessed by western blot, and adiponectin, measured in WAT homogenates, are reduced only in EPI. There was an increase in gene expression of MCP-1 and PAI-1, and was observed smaller area of adipocytes in EPI, with no change in RETRO of HFD fed animals. De novo synthesis of fatty acids (FA), evaluated by incorporation of 3H from 3H2O in FA was higher in both TAB, but the uptake of FA, from blood lipoproteins, evaluated by the activity and expression of lipoprotein lipase (LPL) was increased in EPI and reduced in RETRO. HFD induced increase in phosphorylation of glycerol, evaluated by the activity and content of glycerolkinase (GyK) which increased in both TAB and greater incorporation of 1-14C-glycerol in the TAG only in EPI. The in vitro glucose uptake and GLUT-4 content, which indicates the activity of the glycolytic pathway were reduced in EPI and RETRO, as well as glyceroneogenesis assessed by the incorporation of 1-14C- pyruvate into TAG without changes in the activity and contents of phosphoenolpyruvate carboxykinase (PEPCK). The basal lipolytic activity was evaluated in vitro by glycerol releasing from isolated adipocytes, and was not altered by HFD intake, but when stimulated by noradrenaline glycerol release was lower in HFD animals as well as the phosphorylation of ATGL and HSL and ?3 adrenergic receptor content. HFD led to a reduction in the content of PPAR gamma and an increase in ATF3 in both tissues. In EPI there was an increase in pCREB, pSTAT3 and RGS2 while in RETRO the only difference was reduced pSTAT3. Our results shown that TAB increase is result of increased FA synthesis and uptake, and G3P required for esterification TAG comes mainly from direct phosphorylation of glycerol by GyK; Furthermore, reduced lipolysis also seems to contribute to this scenario. HFD effects seem to be more prominent in EPI than in RETRO

O desenvolvimento de materiais nanoestruturados tem se destacado devido a necessidade de miniaturização de dispositivos e a procura por novos efeitos físicos e químicos capazes de gerar novas tecnologias. Um importante composto com aplicações principalmente em óptica é o YAG (Y3Al5O12) presente no sistema cerâmico alumina-ítria (\'AL IND.2\'O IND.3\'-\'Y IND.2\'O IND.3\'). O YAG apresenta estrutura cristalina cúbica, expansão térmica isotrópica e não apresenta efeitos de birrefringência, o que possibilita a produção de cerâmica transparente para uso como material hospedeiro de íons terras-raras para o desenvolvimento de lasers de estado sólido. O ponto de partida em processamento cerâmico começa com o conhecimento das características físico-químicas do pó do composto. Em nosso trabalho, o objetivo foi o desenvolvimento de uma metodologia para a obtenção de nanopós de YAG de tamanhos médios diferenciados. Para isso foram realizados distintos processos químicos de síntese, e também, foram utilizados diferentes processos de separação, como a centrifugação e a sedimentação. Na produção das nanopartículas foram utilizados três métodos de síntese: Método de Pechini, Rota Glicerol e Método de Coprecipitação. No método de Pechini avaliou-se o efeito de diferentes valores de pH (1, 4, 7, 9 e 11) e procurou-se correlacionar com os tamanhos médios das nanopartículas. Após a obtenção do pó precursor foram realizadas medidas de decomposição térmica (DSC e TG), observando as principais transformações físico-químicas do material decorrentes dos diferentes métodos de síntese. A formação da fase cristalina do YAG foi determinada por difração de raios X e uma análise estrutural foi efetuada por espectroscopia de infravermelho. Medidas de área superficial específica (BET) foram usadas para avaliar o tamanho médio das partículas. Nanopós de YAG com diferentes intervalos de tamanhos foram produzidos, e o rendimento para cada intervalo de tamanho definido. / Nanostructured materials has emerged because the intense interest for miniaturization of devices and crescent demand for new physical and chemical effects that can generate new technologies. An important compound with applications mainly in optics is the YAG (Y3Al5O12). It\'s present in the alumina-yttria ceramic system (\'AL IND.2\'O IND.3\'-\'Y IND.2\'O IND.3\'). The YAG has a cubic crystaline structure, isotropic thermal expansion and it has no birefringence effects, which allows the production of transparent ceramics to use as host of solid-state lasers. The starting point in ceramic processing begins with the knowledge of the characteristics and physical and chemical properties of the powder. In our work, the goal was the development of a methodology for obtaining YAG nanopowders of different average sizes. To do this we performed distinct chemical synthesis, and we also used different separation processes such as centrifugation and sedimentation. For production of nanoparticles we used three synthesis methods: Pechini, glycerol route and coprecipitation. In the Pechini method we evaluated the effect of different pH values (1, 4, 7, 9 and 11) and tried to correlate with the average sizes of nanoparticles. After obtain the precursor powders we studied the decomposition thermal (DSC and TG) process, arising from the different synthesis methods. The crystalline phase of YAG was determined by x-ray diffraction and the structural analysis was carried out by infrared spectroscopy. Specific surface area measurements (BET) were used to evaluate the average particle size.YAG nanopowders with different average sizes were produced.

This diploma thesis is focused on the evaluation of changes in non-freezing heat transfer liquid composed of mixture of polyols and water, used in the real solar thermic system. On the base of the research a new heat transfer liquid is proposed on the platform of 1,3-polyols. The emphasis is put on the non-toxic properties of such system revealing the two chemical candidates for a new heat transfer liquid: 1,3-propanediol and glycerol. These chemicals are mixed together with water using different volume concentrations and properties of such liquids are evaluated.

This thesis deals with the evaluation of changes in properties of an antifreeze heat transfer fluid based on polyols used in real solar thermal system. Emphasis is placed on the use of substances with low impact on the environment.

The scope of thesis was the optimization of methods for the study of yeast and their metabolites using flow cytometry and fluorescence microscopy. Red yeasts are characterized by overproduction of carotenoids and lipids, which are used in food, pharmaceutical and feed industries. Currently, intensive research is being carried on to find appropriate microbiological alternatives for synthesis of these substances. Present thesis is focused on selected yeast genera: Rhodotorula, Sporobolomyces, Cystofilobasidium and strain Phaffia rhodozyma. Yeasts were cultivated on different nutrient media, in which glucose was used as a nutritional source, and also on glycerol and whey as waste material. In two strains - Cystofilobasidium macerans and Rhodotorula mucilaginosa growth characteristics were determined on a synthetic glucose production medium. All studied strains were able to use waste substrates as a source of nutrients. Some of the strains displayed increased production of carotenoids, and, additionally, in some cases also relatively high production of lipids. In classical cultivation in lipid and glucose medium supplemented with vitamins the best production characteristics displayed Rhodotorula glutinisstrain. In glycerol medium the highest amount of carotenoids and lipidic substances produced Sporobolomyces shibatanus strain. Strain Sporobolomyces roseus showed the best production characteristics on whey as the main source of carbon. The results show use of whey and glycerol seems like appropriate option for potential carbon source to cultivate carotenogenic yeasts and production of carotenoids and selected lipidic substances as products with higher added value. Further optimization of nutrient medium on the given substrates is needed for higher production of selected metabolites. Fluorescence microscopy and flow cytometry have proved to be suitable options for determination of the observed metabolites in the cells, their amount and viability.