Submitted by Kaíque Mesquita Cardoso (kaiquemesquita@outlook.com) on 2018-05-14T12:43:17Z No. of bitstreams: 1 cardoso_km_me_botfca.pdf: 2683094 bytes, checksum: 637412d8a97a3cf7e8f5b6e7d0fbcfd4 (MD5) / Approved for entry into archive by Maria Lucia Martins Frederico null (mlucia@fca.unesp.br) on 2018-05-14T13:02:15Z (GMT) No. of bitstreams: 1 cardoso_km_me_botfca.pdf: 2683094 bytes, checksum: 637412d8a97a3cf7e8f5b6e7d0fbcfd4 (MD5) / Made available in DSpace on 2018-05-14T13:02:15Z (GMT). No. of bitstreams: 1 cardoso_km_me_botfca.pdf: 2683094 bytes, checksum: 637412d8a97a3cf7e8f5b6e7d0fbcfd4 (MD5) Previous issue date: 2018-05-09 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O conceito de microbacias hidrográficas reflete a sensibilidade ao regime de precipitação e uso alternativo do solo da área de drenagem. Neste sentido, ao pensar em planejamento territorial, a conservação das microbacias hidrográficas é o que garante o suprimento da quantidade e qualidade do corpo de água à jusante. Assim, sabendo que a exportação dos nutrientes em uma microbacia hidrográfica está relacionada ao manejo exercido na área, e em que, ao depender da sua concentração no sistema aquático pode gerar um processo de degradação ambiental, o objetivo deste trabalho foi avaliar a dinâmica de parâmetros de qualidade da água e a oscilação do índice de estado trófico em duas microbacias hidrográficas. As microbacias estão sob diferentes coberturas de vegetação, e enquanto uma possui vegetação nativa do bioma Mata Atlântica, a outra possui predominância de florestas plantadas de Pinus. Foram coletados dados durante uma série histórica de dez anos (2005 – 2015), com frequência de observação quinzenal. As variáveis aferidas foram os nutrientes nitrato, fósforo, potássio, cálcio e magnésio, assim como parâmetros físicos de sólidos suspensos totais, turbidez e cor aparente. O monitoramento dos parâmetros de qualidade é fruto do Programa Cooperativo sobre Monitoramento e Modelagem de Bacias Hidrográficas (PROMAB) do Instituto de Pesquisas e Estudos Florestais (IPEF). Neste estudo observou-se que apesar do regime de precipitação condicionar a flutuação de alguns nutrientes, a mobilidade dos elementos pode ser em função da solubilidade e reatividade com a água. Não foi observado depreciação da qualidade de água pelo manejo florestal. / The concept of catchments reflects the sensitivity of the precipitation regime and the alternative use of soil in the drainage area. In this sense, when thinking about territorial planning, the conservation of watersheds is what guarantees the supply of the quantity and quality of the water body downstream. Thus, knowing that the export of nutrients in a watershed is related to the management in the area, and that, depending on its concentration in the aquatic system can generate an environmental degradation process, the objective of this work was to evaluate the parameters dynamics of water quality and the oscillation of the trophic state index in two catchments. The watersheds are under different coverages of vegetation, while one of the watershed is surrounded by vegetation native to the Atlantic Forest biome, the another is predominantly planted pine forests. Data were collected during a ten - year historical series (2005 - 2015), with frequency of biweekly observation. The measured variables were nitrate, phosphorus, potassium, calcium and magnesium nutrients, as well as physical parameters of total suspended solids, turbidity and apparent color. The monitoring of the quality parameters is the result of the Cooperative Program on Monitoring and Modeling of Watershed of the Forest Research Institute. In this study it was observed that although the precipitation regime conditions the fluctuation of some nutrients, the mobility of the elements can be in function of the solubility and reactivity with the water. No water quality depreciation was observed by forest management. / 1582576

abstract: Asphalt binder is a complex viscoelastic hydrocarbon, whose performance depends upon interaction between its physical and chemical properties, both of which are equally important to the successful understanding of the material. Researchers have proposed various models linking linear viscoelastic (LVE) and microstructural parameters. However, none of these parameters provide insight into the relationship in the non- linear viscoelastic NLVE domain. The main goals of this dissertation are two fold. The first goal is to utilize the technique of Laser Desorption Mass Spectroscopy (LDMS) to relate the molecular structure of asphalt binders to its viscoelastic properties. The second goal of the study is to utilize different NLVE characterization tools and analysis procedures to get a clear understanding of the NLVE behavior of the asphalt binders. The goals of the study are divided into four objectives; 1) Performing the LDMS test on asphalt binder to develop at the molecular weight distributions for different asphalts, 2) Characterizing LVE properties of Arizona asphalt binders, 3) Development of relationship between molecular structure and linear viscoelasticity, 4) Understanding NLVE behavior of asphalt binders through three different characterization methods and analysis techniques. In this research effort, a promising physico-chemical relationship is developed between number average molecular weight and width of relaxation spectrum by utilizing the data from LVE characterization and the molecular weight distribution from LDMS. The relationship states that as the molecular weight of asphalt binders increase, they require more time to relax the developed stresses. Also, NLVE characterization was carried out at intermediate and high temperatures using three different tests, time sweep fatigue test, repeated stress/strain sweep test and Multiple Stress Creep and Recovery (MSCR) test. For the intermediate temperature fatigue tests, damage characterization was conducted by applying the S-VECD model and it was found that aged binders possess greater fatigue resistance than unaged binders. Using the high temperature LAOS tests, distortion was observed in the stress-strain relationships and the data was analyzed using a Fourier transform based tool called MITlaos, which deconvolves stress strain data into harmonic constituents and aids in identification of non-linearity by detecting higher order harmonics. Using the peak intensities observed at higher harmonic orders, non-linearity was quantified through a parameter termed as “Q”, which in future applications can be used to relate to asphalt chemical parameters. Finally, the last NLVE characterization carried out was the MSCR test, where the focus was on the scrutiny of the Jnrdiff parameter. It was found that Jnrdiff is not a capable parameter to represent the stress-sensitivity of asphalt binders. The developed alternative parameter Jnrslope does a better job of not only being a representative parameter of stress sensitivity but also for temperature sensitivity. / Dissertation/Thesis / Doctoral Dissertation Civil, Environmental and Sustainable Engineering 2018

Introdução - O pescado é amplamente utilizado para a produção de alimentos à base de matéria-prima de origem animal. A importação de pescado vem crescendo ano a ano, sendo o Porto de Santos/SP uma das principais rotas de entrada desse produto no país. Objetivos - Avaliar as condições higienicossanitárias de pescado importado no Porto de Santos/SP. Métodos - A pesquisa foi desenvolvida com base em duas abordagens: estudo dos requisitos obrigatórios para nacionalização do produto importado com base na legislacão vigente e trabalho desempenhado pelo Vigiagro/MAPA, assim como, estudo laboratorial. Foram coletadas 60 amostras de 30 diferentes produtos de pescado sendo cada amostra constituída por, no mínimo, 500 g do produto de uma mesma marca, lote, data de fabricação e validade. Uma parte das amostras, 30 embalagens de 500 g no mínimo, foi acondicionada em caixas isotérmicas com temperatura controlada e encaminhada para realização das análises microbiológicas. As demais 30 embalagens foram encaminhadas, sob as mesmas condições, para realização das análises físico-químicas. As análises físico-químicas e microbiológicas foram realizadas em Laboratórios credenciados no Mapa. Para produtos congelados foram realizadas as análises microbiológicas para pesquisa de Salmonella spp em 25 gramas e contagem de Staphylococcus coagulase positiva e realização das análises físico-químicas de N-BVT. Para produtos salgados refrigerados, foram realizadas análises microbiológicas para pesquisa de Salmonella spp em 25 gramas, contagem de Staphylococcus coagulase positiva e contagem de coliformes termotolerantes a 450 C, assim como, realização das análises físico-químicas de umidade e resíduo mineral fixo. Resultados - Nos produtos congelados, as análises físico-químicas para o N-BVT e as análises microbiológicas para pesquisa de Salmonella spp em 25 gramas e contagem de Staphylococcus coagulase positiva indicaram 100,0% de conformidade com a legislação vigente. Nos produtos salgados refrigerados, as análises microbiológicas para pesquisa de Salmonella spp em 25 gramas, contagem de Staphylococcus coagulase positiva e contagem de coliformes termotolerantes a 450 C também indicaram 100,0% de conformidade com a legislação vigente. Por outro lado, 100,0% das análises físico-química de umidade e 44,4% das análises físico-químicas para resíduo mineral fixo no pescado salgado resfriado estavam com valores acima da legislação vigente. Todos os produtos apresentaram documentação obrigatória e rótulo de acordo com a legislação vigente. Conclusão Embora os resultados das análises microbiológicas tenham demonstrado que os produtos estivessem próprios para o consumo, as análises físico-químicas, em específico os parâmetros referentes a umidade no pescado salgado refrigerado, não estavam de acordo com os valores determinados pela legislação vigente. A legislação sanitária vigente para importação de pescados, assim como a metodologia de inspeção e fiscalização desses produtos, se mostrou eficiente comparado aos resultados laboratoriais encontrados, com possibilidade de inclusão de novas ferramentas e análises laboratoriais visando garantir, ainda mais, as condições higiênicossanitárias e segurança alimentar. / Introduction - Seafood is widely used for the production of food based on raw materials of animal origin. The fish import has been growing year by year, and the Port of Santos / SP one of the main routes of entry of that product in the country. Objectives - To evaluate the hygienic-sanitary conditions of imported fish in the Port of Santos / SP. Methodology - The study was based up on two approaches: study of the mandatory requirements for nationalization of the imported product on the basis of current legislation and work performed by Vigiagro / MAPA, as well as laboratory study. It was collected 60 samples from 30 different products of fish each sample being composed by 500 g from the same brand, batch number, manufacturing and expiration date. A share of these samples, 30 packages of 500 g at least, was accommodated and transported in temperature-controlled isothermal box to the microbiological analysis. The remaining 30 packages were sent, under the same conditions, to physico-chemical analysis. The physico-chemical and microbiological analyzes were performed in laboratories accredited on MAPA. For frozen products were performed microbiological analyzes for Salmonella spp research in 25 g Staphylococcus and count coagulase positive and achievement of physical and chemical analysis of N-BVT. For salted products, microbiological analyzes were performed for detection of Salmonella spp in 25 g, Staphylococcus coagulase positive count and count of coliform to 450 C and physical-chemical analysis for humidity and fixed mineral residue. Results - In the frozen products, physico-chemical analysis for the N-BVT and microbiological analyzes for Salmonella spp research in 25 g and Staphylococcus coagulase positive counts indicated 100.0% of compliance with current regulation. In salted products, microbiological analyzes for Salmonella spp research in 25 g, Staphylococcus coagulase positive and coliform to 450 C counts also indicated 100.0% compliance with current legislation. On the other, 100.0% of the physico-chemical analysis of humidity and 44,4 % in the ashs physico-chemical results, in salted fish, were with higer limits established by Brazilian legislation. All products submitted mandatory documents required for import and labeling in accordance with current regulation. Conclusion - Although the results of the microbiological analyzes showed that the imported fish were apropriate for consumption, the physico-chemical analysis, in particularly the humidity parameters were not in accordance with values indicated in the current regulation. The current health regulation for the imported fish, as well as the inspection methodology and supervision of these products, was efficient compared to laboratory findings, with the possibility of adding new tools and laboratory tests to ensure even more the higienic-sanitary conditions and food safety.

A solubilização de solutos não iônicos através de um processo de partição entre água e a pseudo-fase micelar de tensoativos não iônicos foi estudada para álcoois secundários etoxilados com grau de etoxilação variando entre 7 e 40. Mostrou-se que o coeficiente de incorporação micelar, Ks, é independente do grau de etoxilação o que corrobora a hipótese de que a partição ocorre entre água e o núcleo hidrocarbônico da micela, que não é alterado pelo aumento do número de grupos de óxido de eteno na cabeça polar do tensoativo. O uso de relações lineares de energia livre, LSER, para a predição da capacidade de solubilização de álcoois secundários etoxilados forneceu, através de regressão múltipla linear a seguinte LSER como melhor modelo: log Ks = -0,42 + 1,21E - 1,73S -0,40A - 1,13B + 3,01V com R2 = 0,98 e valor de teste F de 1390. Nesta equação, V é o volume molar do soluto, A e B são a capacidade do soluto de atuar como doador e aceptor de pontes de hidrogênio, E é a refração molar em excesso e S representa a capacidade do soluto de interagir com o meio de solubilização através de interações do tipo dipolo-dipolo e dipolo-dipolo induzido. Mostrou-se que processos de limpeza aplicados à remoção de sujidades de tecidos e superfícies sólidas não estão correlacionados ao mecanismo de solubilização descrito por um processo de partição. A dependência da redução de tensão interfacial com o grau de etoxilação sugere que a eficiência de limpeza, para superfícies sólidas e para tecidos, está correlacionada de maneira direta, mas não linear, com a capacidade do tensoativo de concentrar-se na interface \"sujidade-solução aquosa de tensoativo\" reduzindo assim a tensão interfacial entre os dois meios. / The solubilization of non-ionic solutes via partitioning between water and the micellar pseudophase of non-ionic surfactants was evaluated for a series of secondary alcohol ethoxylates with hydrophile length varying from 7 to 40 ethylene oxide units. It was demonstrated that the micellar incorporation constant, Ks, is not dependent on the hydrophile length of the surfactant. The results obtained in this study support the hypothesis that the partitioning between water and the micellar core is not disturbed by the etheylene oxide hydrophilic groups. Linear solvation free energy relationships, LSER, were used to model the ability of the surfactants to solubilize non-ionic compounds. Multiple linear regression analysis provided the following LSER with R2 of 0.98 and F value of 1390: logK = -0,42 + 1,21E - 1,73S - 0,40A - 1,13B + 3,01V. In this LSER, V is a descriptor of solute molar volume, A and B capture the overall ability of the solute to act as a hydrogen bond donor and acceptor, E is the solute excess molar refraction and S is a descriptor of the ability of the solute to interact via dipole-dipole and dipole-induced dipole interactions with its surroundings. It was demonstrated that hard and soft surface cleaning efficiencies are not correlated with the solubilization process. It was shown, however, that the change in interfacial tension caused by the change in the hydrophile portion of the surfactants has a direct, but non-linear impact on the cleaing properties of aqueous solutions containing these surfactants.

O presente estudo teve como objetivo avaliar a influência do protocolo de secagem com álcool isopropílico à adesividade dos cimentos AH Plus, Hybrid Root Seal e Epiphany SE à dentina radicular. Oitenta raízes de caninos foram submetidas ao preparo biomecânico e distribuídas em 2 grupos de acordo com a secagem, previamente a obturação: I- Secagem cone de papel absorvente e II- Secagem com álcool isopropílico 70%,e posteriormente distribuídas em 8 grupos (n=10): IA e IIA cimento AH Plus; IB e IIB - cimento Hybrid Root Seal; IC e IIC- cimento Epiphany SE com guta percha e ID e IID cimento Epiphany SE com Resilon. Após a obturação, 80 raízes foram seccionadas transversalmente obtendo-se 3 slices de 1,0 mm de espessura para cada terço radicular. Um slice de cada terço foi submetido ao teste de push out e tipo de falha analisado por meio de lupa estereoscópica. Os dois slices restantes foram submetidos à MEV para análise da interface adesiva e superfície do material obturador. A análise de variância evidenciou haver diferença estatisticamente significante (p<0,05) entre os materiais obturadores, o protocolo de secagem do canal radicular e a interação destes fatores. AH Plus/ guta percha obteve os maiores valores médios de resistência de união (3,83 ± 0,45 MPa), sendo estatisticamente diferente (p<0,05) dos demais. O Hybrid Root SEAL/ guta percha (3,24 ± 0,46 MPa) obteve valores intermediários, sendo estatisticamente diferente dos demais (p<0,05). O cimento obturador Epiphany SE quando associado à guta percha (0,45 ± 0,10 MPa) ou ao Resilon (0,31 ± 0,09 MPa) obteve os menores valores de adesividade, sendo estatisticamente semelhantes entre si (p>0,05) e diferentes dos demais (p<0,05). O cimento AH Plus obteve os maiores valores de adesividade independente do protocolo de secagem utilizado. Na comparação entre os protocolos, o protocolo que utilizou álcool isopropílico 70% obteve maiores valores médios de adesividade. / The purpose of the present study was to evaluate the influence of the drying protocol with isopropyl alcohol on the adhesion of the sealers AH Plus, Hybrid Root Seal and Epiphany SE to intraradicular dentin. Eighty root canals of canines were subjected to biomechanical preparation and were allocated to receive one of the following drying protocols (n=40) prior to root canal filling: I- Drying with absorbent paper point and II- Drying with 70% isopropyl alcohol. Thereafter, 8 groups (n=10) were formed according to the filling material: IA and IIA AH Plus sealer; IB and IIB - Hybrid Root Seal sealer; IC and IIC- Epiphany SE sealer with gutta-percha; and ID and IID Epiphany SE sealer with Resilon. After filling, the 80 roots were sectioned transversally to obtain three 1.0-mm-thick slices from each root third. The first slice of each third was subjected to a push-out test and the failure mode was determined with a stereoscopic lens. The other two slices were prepared for SEM to examine adhesive interface and the surface of the filling materials. Analysis of variance revealed statistically significant difference (p<0.05) among the filling materials, between the root canal drying protocols as well as for the interaction of these factors. AH Plus/gutta-percha had significantly higher (p<0.05) bond strengths (3.83 ± 0.45 MPa) than the other materials. Hybrid Root SEAL/gutta-percha (3.24 ± 0.46 MPa) had intermediate values and differed significantly from the other materials (p<0.05). Epiphany SE combined with either gutta-percha (0.45 ± 0.10 MPa) or Resilon (0.31 ± 0.09 MPa) presented the lowest bond strengths without statistically significant difference (p>0.05) from each other, but with significant difference (p<0.05) from the other materials. AH Plus present the highest bond strengths regardless of the drying protocol. Comparing the two protocols, drying of root canals with 70% isopropyl alcohol was associated with the highest bond strength values to intraradicular dentin.

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

La caractérisation des complexes de van der Waals est déterminante pour la compréhension et la modélisation des atmosphères planétaires et du milieu interstellaire. Cependant, ces agrégats moléculaires sont assez peu étudiés, particulièrement dans l’infrarouge proche. Cette thèse a pour but d’enrichir les connaissances sur les complexes d’eau et d’ammoniac dans cette région spectrale. Pour cela, nous avons utilisé un montage expérimental appellé FANTASIO+, couplant une expansion su- personique à un spectromètre à temps de déclin (CRDS). Plusieurs complexes de van der Waals ont pu être observés et analysés, à savoir 14/15NH3−Ar/Kr, (H2O)2, H2O−Ar/Kr et HDO−N2O.Ces complexes peuvent être décrits par deux régimes selon la hauteur de la barrière du potentiel intermoléculaire. Les complexes caractérisés par un potentiel inter- moléculaire élevé peuvent être traités par le régime semi-rigide, à savoir comme une molécule à part entière avec des constantes rotationelles bien définies [(H2O)2 et HDO−N2O]. Dans le régime du rotateur libre, au contraire, le monomère du complexe est soumis à une faible barrière de potentiel, et donc sa rotation est pra- tiquement libre (tous les complexes 14/15NH3− et H2O−gaz rare).Le déplacement et la séparation des niveaux d’énergie robivrationels du monomère dépend de l’effet de l’anisotropie du potentiel intermoléculaire par rapport au lien intermoléculaire. Les transitions entre ces sous-états sont appelées des sous-bandes.Les spectres observés dans ce travail de thèse correspondent à l’excitation vibra- tionnelle de 14/15NH3, H2O ou HDO. L’analyse rotationelle des sous-bandes a pu être réalisée pour toutes les espèces (y compris les 4 isotopes principaux du krypton dans H2O−Kr), excepté pour 15NH3−Kr car la sous-bande observée était à peine visible. Nous avons pu caractériser la structure rotationnelle de 1 (15NH3−Ar) à 14 (H2O−Ar) sous-états vibrationnellement excités et de l’état fondamental pour toutes les espèces sauf 14NH3−Kr, 15NH3−Ar/Kr et (H2O)2. Notre travail sur ce dernier, basé sur des calculs théoriques et sur une étude similaire en matrice de néon, est la première analyse rotationelle de ce complexe dans cette région spectrale. Les analyses des spectres de H2O−Ar et HDO−N2O s’appuient sur des calculs ab initio. Pour HDO−N2O, nous avons pu déterminer que le lien OD se trouve plus proche de N2O que le lien OH. Les spectres de 14/15NH3−Ar/Kr présentent des sous-bandes appartenant à des complexes de taille plus importante. Un séjour à l’Université d’Alberta a été organisé afin d’identifier la nature de ces complexes.Quand l’analyse rotationelle a pu être réalisée, nous avons déterminé les temps de vie de prédissociation des sous-états excités (sauf pour HDO−N2O car le signal-sur- bruit était trop faible). Ils sont de 20 ps pour (H2O)2 à 4 ns pour H2O−Ar. Nous avons observé que les temps de vie déterminés étaient inversement proportionnels à l’énergie de dissociation des complexes. Le déplacement observé entre l’origine des sous-bandes par rapport à la bande correspondante du monomère suit égale- ment la même tendance que l’énergie de dissociation du complexe. Nous avons pu déterminer les températures rotationnelles pour toutes les espèces dans le jet super- sonique. Celles-ci sont différentes uniquement dans le cas de 14NH3−Ar.Des spectres des monomères 14NH3 et 15NH3 ont également été enregistrés, notamment en utilisant un spectromètre à transformée de Fourier, enrichissant ainsi les données spectroscopiques de ces molécules dans l’infrarouge proche. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

Afin de s’affranchir de contraintes liées à l’utilisation de milieux conventionnels, l’électroreduction du CO2 a été étudiée en milieux liquides ioniques. L’activité de l’interface électrode - électrolyte a été examinée par techniques électrochimiques et les produits de réactions formés après électrolyses sous contrôle potentiostatique, ont été analysés par techniques chromatographiques et spectroscopie RMN. L’ensemble des informations obtenu lors de ces analyses a permis de contribuer à une meilleure compréhension des mécanismes réactionnels de l’électroréduction du CO2 en milieux liquides ioniques. Au travers de ce travail, l’influence de la composition du liquide ionique sur l’électroréduction du CO2 conduite à une électrode d’or a pu être étudiée, en recourant à des liquides ioniques constitués de différents cations (imidazolium, pyrrolidinium, pipéridinium et tétraalkylammonium) et du même anion [NTf2]-. En milieu [BMIm][NTf2], la présence du proton acide H-2 du cation [BMIm]+ favorise la formation de CO, principal produit formé à l’électrode d’or polycristallin. Cependant, la réduction du cation [BMIm]+ apparaît comme une réaction compétitive, produisant non seulement du carbène, mais également des dimères hydrogénés et un monomère. La différence de sélectivité de ces produits observée à différents matériaux d’électrode a pu être interprétée sur base des capacités différentes des surfaces métalliques à adsorber l’hydrogène. En présence de ces produits générés électrochimiquement, le CO2 est indirectement converti produisant en partie un adduit. Dû fait de la faible chargée transféree durant électrolyse en milieu [N1,1,1,3][NTf2] et des grandes surtensions nécessaires à la réduction du CO2 en milieu [PMPip][NTf2], l’électroréduction du CO2 a été poursuivie en détail en milieu [BMPyrr][NTf2].En milieu [BMPyrr][NTf2], la réduction du cation n’apparaît plus comme une réaction compétitive, et CO peut être formé sélectivement avec d’excellentes efficacités faradiques, sans consommation des protons du liquide ionique. Dans ce milieu, la formation de CO est seulement inhibée à des potentiels plus négatifs par la formation d’oxalate, la dégradation de l’anion [NTf2]- et par la corrosion cathodique de l’électrode d’or. De plus, le présent travail a montré que la sélectivité pour la formation de CO et d’oxalate est affectée par la nature du matériau d’électrode, grâce à l’utilisation d’une surface de cuivre. A une électrode de cuivre polycristallin, la présence d’une source de proton, telle que H[NTf2], permet également la formation de produits à haute valeur ajoutée, telle que le méthane ou l’acide formique.A une électrode d’or polycristallin, la formation d’adduits en présence de CO2 n’a pas seulement été observée en milieu [BMIm][NTf2], mais également après ajout d’un co-réactant, telle que des bipyridines, en milieu [BMPyrr][NTf2]. Le mécanisme de réaction diffère cependant selon la structure de la bipyridine. / To avoid limitations encountered in conventional media, the electroreduction of CO2 has been studied in ionic liquids. The activity of the ionic liquid - electrode interface was examined by electrochemical techniques and the reaction products were analysed after controlled-potential electrolysis, by chromatographic techniques and NMR spectroscopy. The information obtained by these analysis have contributed to a better understanding of the reaction pathways of the electroreduction of CO2 in ionic liquids media. In this work, the influence of the ionic liquid composition on the electroreduction of CO2 conducted at gold electrodes was studied by resorting to ionic liquids composed of different cations ( imidazolium, pyrrolidinium, piperidinium and tetraalkylammonium) and the same anion [NTf2]−. In [BMIm][NTf2], the presence of acidic H-2 proton on the [BMIm]+ cation favours the formation of CO, main product formed at Au (poly). However, the reduction of the [BMIm]+ cation appears as a competitive reaction, producing not only carbene, but also hydrogenated dimers and a monomer. The selectivity of these electrogenerated products observed at various electrode materials, has been interpreted taking into account the distinct H-adsorption abilities of the metallic surfaces. In the presence of these electrogenerated products, CO2 is indirectly converted into an adduct. In ammonium-based ionic liquids, the electroreduction has been investigated in detail only in [BMPyrr][NTf2], since inhibition of the charge transfer and a high overpotential for the reduction of CO2 were observed in [N1,1,1,3][NTf2] and [PMPip][NTf2], respectively.By contrast, in [BMPyrr][NTf2], presenting no reduction reaction of the cation in competition with the CO2 electroreduction at Au (poly), the formation of CO can be selectively formed with excellent faradaic efficiency and without consumption of the RTILs protons. The selectivity for the formation of CO only decreases at more negative potentials, since the formation of oxalate, the decomposition of the [NTf2]- anion and a cathodic corrosion of the gold electrode may also take place. It has been shown that the selectivity for the formation of CO and oxalate is affected by the nature of the electrode material, using a copper surface. At Cu (poly), the presence of an additional source of proton, such as H[NTf2], to [BMPyrr][NTf2] also provides the formation of methane or formic acid.At Au (poly), the formation of adducts in the presence of CO2 has not only been observed in [BMIm][NTf2], but also after the addition of co-reactant, such as bipyridines, in [BMPyrr][NTf2]. The reaction mechanism differs, however, according to the structure of bipyridine. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

Industriellement, les problématiques d‘adhésion polymère/métal se rencontrent dans de nombreux secteurs tels que l'industrie automobile, ou les applications aéronautiques et électroniques. Les polyuréthanes (PU) sont fréquemment utilisés comme adhésifs structuraux, et sont obtenus à partir de polyols provenant de la pétrochimie (polyester et polyéther polyols). Cependant, ces produits ont des inconvénients notables sur le plan écologique car ils sont produits à partir de ressources non renouvelables, ils peuvent également générer une pollution de l'environnement, et leurs matières premières de départ sont d‘une part de plus en plus coûteuses et d‘autres part amenées à se raréfier dans les années à venir. Le caoutchouc naturel (NR) est une alternative intéressante aux polyols de synthèse car il est issu d‘une ressource végétale (hévéa), renouvelable et abondante, et également car il présente des propriétés mécaniques intéressantes. De plus, il peut être facilement modifié chimiquement, afin notamment d‘apporter des groupements hydroxyle capables de réagir ensuite avec des fonctions isocyanate pour former un polyuréthane. Dans ce travail, le polyisoprène hydroxytéléchélique (HTPI) ayant une fonctionnalité en hydroxyle de 2 a été synthétisé avec succès par époxydation contrôlée suivie de coupure oxydante de polyisoprène de hautes masses, puis réduction sélective des oligoisoprènes carbonyltéléchéliques obtenus. Ces HTPI de différentes masses molaires (1000-8000 g mol-1) ont été obtenus de façon reproductible. Des modifications chimiques ont été effectuées par époxydation à différents taux (10-60% EHTPI). Les différentes microstructures de ces oligomères ont été mises en évidence par FT-IR, RMN and SEC. Leurs propriétés thermiques ont été déterminées par ATG et DSC. Les propriétés de surface (énergie de surface, microscopie optique) et les propriétés d‘adhésion (test de clivage) de différents matériaux ont été caractérisées. Les échantillons à base de HTPI pur (sans époxyde) présentent un niveau d‘adhésion élevé. Des taux d‘époxydation proches de 30-40% permettent d‘obtenir des performances adhésives intéressantes. D‘autre part, l‘effet de la masse molaire est faible(cependant, une masse molaire plus élevée entraîne globalement une meilleure adhérence). Le niveau d‘adhérence observé est similaire à ceux mesurés pour des adhésifs structuraux utilisés dans l‘industrie automobile ou aéronautique. Le test de clivage est un test d‘adhérence sévère pour un joint adhésif, et les faibles propagations de fissures observées pour certaines formulations permettent d‘escompter des développements industriels prometteurs pour ces nouveaux polymères. / Industrially, metal/polymer adhesion is involved in a wide range of industries such as automotive industry, or aeronautic and electronic applications. Polyurethanes (PU) are frequently used as structural adhesives, and are based from polyols obtained from petrochemical products (polyester and polyether polyols). However, these products have some disadvantages as they are non-renewable resources, they may cause environmental pollution, and they tend to be exhausted in the near future. Natural rubber (NR) is an interesting choice to use as a starting material in PU synthesis, due to the fact that they are renewable source, abundant polymer and they have interesting mechanical properties and can be chemically modified. In this work, hydroxytelechelic polyisoprene (HTPI) having a hydroxyl functionality of 2 was successfully performed via controlled epoxidation and cleavage of high molecular weight polyisoprene, following by a selective reduction reaction of the obtained carbonyltelechelicoligoisoprenes. These HTPI with different molecular weights (1000-8000 g mol-1) were reproducible obtained. Chemical modifications on HTPI were performed by various percentage of epoxidation (10-60%, EHTPI). The different microstructures of these oligomers were evidenced by the characterization techniques FT-IR, NMR, SEC. Their thermal properties were also investigated by TGA and DSC.Surface properties (surface energy, optical microscopy) and adhesion properties (wedge test) of different materials have been characterized. To resume adherence results, pure HTPI samples (without any epoxy group) present a very high adhesion level. Epoxidation degrees close to 30-40% allow to obtain interesting adhesive performance. Elsewhere, the effect of molecular weight is slight (nevertheless, a higher Mn of HTPI induces globally a better adherence). The adherence level is similar to whose measured for structural adhesive used in car or aeronautic industry. The wedge test is a severe adherence test, and the low crack propagation observed for some formulations underlines promising industrial developments for this new polymers.

Les eaux-de-vie (EDV) de cognac sont issues de la distillation de vin blanc, qui croit dans une région délimitée en zones de crus. Selon le cru d’origine de leur vin, les EDV sont réputées typiques, sur des notions sensorielles. Ainsi, des analyses physico-chimiques et sensorielles ont été mises en œuvre en parallèle enfin de rechercher cette typicité supposée de cru dans des EDV nouvelles (juste après distillation) et dans des EDV après vieillissement en fût de chêne. Un travail de filiation des composés d’impact dans les vins a également été mené. Aucun composé spécifique de cru n’est ressorti des analyses et les différences à mettre en évidence sont ténues. L’effet cru a été prouvé seulement lors d’échantillonnages sélectifs et de techniques spécifiques. En effet, plusieurs facteurs, tels que la distillation, capable de modifier la composition aromatique des EDV et donc leur perception sensorielle, semblent supérieurs à l’effet cru et pourraient en masquer les typicités. De plus, les typicités de cru semblent évoluer au cours du temps, entre le vin, l’EDV nouvelle et l’EDV vieillie. En conclusion, l’effet cru semble faible comparé à d’autres facteurs, et pourrait être dû à divers mélanges possibles des mêmes molécules retrouvées dans tous les échantillons. Il s’agirait d’un équilibre aromatique entre les concentrations de ces molécules, avec certains composés éventuellement prépondérants dans la balance et d’autres plus ubiquitaires, qui permettrait d’exprimer les typicités sensorielles des échantillons, en fonction de leur cru d’origine. / Cognac spirits are made from the distillation of white wine, growing in a region delimitated into cru areas. According to the cru of origin of their wine, spirits are assumed to be typical, in a sensorial way. Then, physico-chemical and sensorial analysis were carried out in parallel in order to search for this supposed typicality of cru, in freshly distilled spirits such as in spirits after aging in oak barrels. A work of filiation of impact compounds in the wines was also done. No cru-specific compound was found and differences to put in evidence are thin. The cru effect was apparent only with selective sampling and specific methodology. Actually, several factors, such as distillation, are able to modify the aromatic composition of spirits so their sensorial perception, and seem higher to the cru effect and could masked its typicality. Moreover, the cru typicality seems to evolve over the time, between wine, freshly distilled and aged spirits. To conclude, the cru effect seems weak compared to other factors. It may be caused by various possible mixes, of the same molecules found in all samples. It would be due to an aromatic equilibrium between the concentrations of these molecules, which allows the sensorial typicality of samples to be expressed, according to their cru of origin.