L’émollience est un terme définissant la capacité d’une matière première à adoucir, amollir, ou lubrifier la peau. Dans le domaine de la cosmétique, les émollients sont utilisés pour modifier la consistance, la viscosité ou la polarité d’une formulation. Il existe un nombre non négligeable d’émollients pouvant être utilisés en cosmétique. Cependant, les données aussi bien physico-chimiques que sensorielles disponibles dans la littérature sont encore très rares, rendant le choix des émollients complexe. De plus, les analyses sensorielles habituellement réalisées par les fournisseurs constituent une méthode de caractérisation particulièrement chronophage et coûteuse.Parmi les différents types d’émollients, les dérivés siliconés se démarquent par des propriétés bien spécifiques. Il s’agit notamment d’un très bon étalement, un toucher doux, non huileux et non collant, ou encore d’un effet sec sans effet de fraicheur. Cependant, malgré ces propriétés sensorielles exceptionnelles, de récentes études soulèvent la question de la toxicité d’un dérivé cyclique particulièrement utilisé dans les produits cosmétiques : le décaméthylcyclopentasiloxane (D5). Ainsi, deux problématiques font le sujet de ces travaux : une portant sur la recherche d’un substituant biosourcé au D5 et pour laquelle des molécules commerciales et synthétisées ont été caractérisés et comparés par des mesures physico-chimiques et sensorielles. La seconde problématique repose sur la recherche de corrélations entre les données physico-chimiques et sensorielles dans le but de faciliter le travail des formulateurs lors du screening des émollients par la prédiction de certaines de leurs propriétés sensorielles. / Emolliency is a word used to define the ability of a compound to soften or lubricate the skin. ln the cosmetic field, emollients are used to modify the consistency, the viscosity or the polarity of a formulation. Many emollients can be used in cosmetic products. However, in the literature both physicochemical and sensory data ar still lacking, making it difficult to choose an emollient. Furthermore, the sensory analysis usually performed to characterize emollients are particularly time-consuming and thus, expensive. Among the different chemical families of emollients, silicone derivatives stand out thanks to their specific properties. Indeed, they are characterized by an excellent spreading on skin and hair, a smooth skin feel, non-greasy and non-sticky, or by a dry skin feel without a fresh effect. However, even though these sensory properties are exceptional, recent studies wonder about the toxicity of a cyclic silicone particularly used in cosmetic products: the decamethylcyclopentasiloxane (D5). Thus, this work deals With two main objectives. The first one consists in the research of a bio-based alternative to the D5 For this purpose, a number of commercial and synthesized molecules were characterized and compared With physicochemical measurements and sensory analysis, allowing the observations of trends between structures and properties. The second objective relies on the study of correlations between physico-chemical and sensory data in order to predict the emollient properties of cosmetic ingredients. This would ease the work of formulators during the screening of ingredients.

Cette thèse porte sur la fonctionnalisation de la pectine de citron par des composés phénoliques. Une première stratégie a consisté à greffer les produits issus de l’oxydation de l’acide férulique (AF), en milieu aqueux (pH 7,5, 30 ° C), en présence de la laccase de Myceliophthora thermophila (obtention de pectine F). L’enjeu était de démontrer le greffage covalent de composés phénoliques exogènes sur le polysaccharide, de recueillir des informations sur la structure et les propriétés du polymère fonctionnalisé et de les comparer aux caractéristiques du polymère natif. Une deuxième stratégie de fonctionnalisation de la pectine a été envisagée, basée sur l'adsorption des produits d'oxydation de l'AF sur la pectine (obtention de pectine POX). Quel que soit le mode de fonctionnalisation, des analyses biochimiques ont montré l'incorporation de composés phénoliques dans la pectine. La structure et les propriétés des pectines modifiées dépendent du type de fonctionnalisation subie par le polysaccharide (greffage covalent ou adsorption). Des analyses structurales suggèrent que le greffage covalent de phénols fait intervenir les fonctions carboxyles de la pectine (formation de liaisons ester) sur lesquelles des oligomères d'acide férulique viendraient se lier. Les propriétés des pectines fonctionnalisées (POX et F) et de la pectine native ont été étudiées et comparées afin de mettre en évidence les changements apportés. L'étude des propriétés thermiques des différentes poudres de pectine suggèrent une structure moins organisée et moins compacte pour les polymères fonctionnalisés par rapport à la pectine native. L’activité antioxydante des pectines fonctionnalisées est améliorée tandis que leur caractère hygroscopique est diminué en raison de l'incorporation de composés phénoliques hydrophobes. De même que la pectine native, les pectines POX et F présentent un profil rhéofluidifiant. Toutefois, la viscosité et la vitesse de gélification mesurées dans le cas de la pectine F sont significativement diminuées par rapport à celles obtenues pour la pectine native. La pectine POX présente un comportement intermédiaire. Des résultats préliminaires d'assemblages ont montré qu'il est possible d'associer la pectine native ou modifiée à un autre polysaccharide, le chitosane. Les microparticules obtenues ont montré leur capacité à encapsuler un principe actif tel que la curcumine / This dissertation concerns the functionalization of the citrus pectin with phenolic compounds. A first strategy consisted in grafting the products issued from the oxidation of ferulic acid (FA), in aqueous medium (pH 7,5, 30 ° C), in the presence of the laccase of Myceliophthora thermophila (pectin F). The main objectives were to demonstrate the covalent grafting of exogenous phenols onto the polysaccharide, to collect information about the structure and the properties of the modified polymer and to compare them with the characteristics of the native one. A second strategy of functionalization was applied, based on the adsorption of FA oxidation products onto the pectin (pectin POX). Whatever the functionalization pathway, biochemical analyses showed the incorporation of phenolic compounds into the pectin. The structure and the properties of the modified pectins depended on the type of modification undergone by the polysaccharide (covalent grafting or adsorption). Structural analyses suggested that the covalent grafting of phenols involved the carboxyl groups of the pectin (ester bound) on which FA oligomers were bound. The properties of native and modified pectins (POX and F) were studied and compared aiming to highlight the changes brought by functionalization. The study of the thermal properties of pectin POX and F suggested less organized and less compact structures compared to the native one. The antioxidant activity of the modified pectins was improved whereas their hygroscopic character was decreased because of the incorporation of hydrophobic phenolic compounds. As the native pectin, the pectins POX and F presented a shear-thinning profile. However, the viscosity and the gelation rate measured for the pectin F were significantly decreased, compared with those obtained for the native pectin. The pectin POX presented an intermediate behavior. Preliminary results of assemblies demonstrated the possibility to associate the native or modified pectin to another polysaccharide, the chitosan, leading to microparticles capable to encapsulate an active ingredient such as the curcumin

The aim of the study was to evaluate the nutritional value and functional properties of several bovine whey proteins concentrate (WPC35 and WPC80), hydrolysate (WPH) and isolate (WPI), casein was used as control. Physicochemical (chemical composition, essential and non-essential aminoacids, minerals) and biological assays were performed to assess the biological quality of proteins and their metabolic responses. After determination of essential and non-essential amino acids, it was found that all protein sources meet the recommendations of FAO/WHO (2007), with the exception of WPC35, probably due to its reduced protein content. The determination of macro and microelements revealed that proteins from bovine milk can be considered not only a source of essential and non-essential amino acids, but also minerals (Ca, Mg and K). Iodine concentration was about one order of magnitude greater for whey proteins and sodium was found in large quantities in these proteins, which can reach 70% and 59% of DRIs, respectively. The biological assay allowed the monitoring of weight gain, food consumption, feed efficiency ratio (FER) and protein intake of animals, evaluate the quality and the metabolic response of protein sources, and the integrity of certain organs and the morphology of the small intestine animals. These studies revealed that all protein sources are of high nutritional value (except WPC35), but larger beneficial biological effects were observed for WPC80, WPH and WPI. Because of the bitter taste of WPH, microencapsulation was made by spray-drying, which significantly improved the taste of panel test (Triangular Test). Considering the presented results, it is concluded that the WPH offers favorable characteristics for use with ingredient in foods for special purposes and that the microencapsulation process yields a significant improvement in flavor, expanding the possibilities for development of foods purposes added hydrolysed proteins, such as infant formula. Some commercial formulations for infants were evaluated with respect to mineral content indicating that the amount of Ca, K and Zn found were considered out of standard of Brazilian law, while the Cu, Mn and Zn levels were very different from those described in label. / O objetivo do estudo foi avaliar o valor nutricional e propriedades funcionais das proteínas do soro de leite bovino concentrado proteico (WPC35 e WPC80), hidrolisado proteico (WPH) e isolado proteico (WPI), além de uma proteína do leite bovino, a caseína, utilizada como controle. Para tanto, foram realizados ensaios físico-químicos (composição centesimal, aminoácidos essenciais e não-essenciais, minerais) e biológicos para avaliar a qualidade proteica e a resposta metabólica das fontes proteicas. Após determinação de aminoácidos essenciais e não-essenciais, foi verificado que todas as fontes proteicas atendem as recomendações estabelecidas pela FAO/WHO (2007), com exceção do WPC35 provavelmente em função do teor reduzido de proteínas. A determinação de macro e microelementos revelaram que as proteínas do leite bovino podem ser consideradas não apenas uma fonte de aminoácidos essenciais e não-essenciais, mas também de minerais (Ca, Mg e K). Para iodo a concentração foi cerca de uma ordem de magnitude superior para as proteínas do soro do leite e sódio foi encontrado em grande quantidade nas proteínas do soro do leite, podendo atingir até 70% e 59% das DRIs, respectivamente. O ensaio biológico permitiu acompanhar o ganho de peso, consumo alimentar, quociente de eficácia alimentar (QEA) e proteína ingerida dos animais, avaliar a qualidade proteica e a resposta metabólica das fontes proteicas, além da integridade de alguns órgãos e histomorfometria do intestino delgado dos animais. Estes estudos revelaram que todas as fontes proteicas são de alto valor nutricional (com exceção do WPC35), mas que maiores efeitos biológicos benéficos foram observados para WPC80, WPH e WPI. Devido ao sabor amargo do WPH, foi feita a microencapsulação por spray-drying, que melhorou de forma significativa o sabor na análise sensorial (Teste Triangular). Considerando-se os resultados apresentados, conclui-se que, o WPH contempla características favoráveis para ser utilizado com ingrediente em alimentos para fins especiais e que o processo de microencapsulação proporcionou uma melhoria significativa no sabor, ampliando as possibilidades de desenvolvimento de alimentos adicionados de proteínas hidrolisadas, tais como fórmulas infantis. Algumas formulações comerciais para lactentes foram avaliadas com relação ao teor de minerais indicando que a quantidade de Ca, K e Zn encontradas foram consideradas fora dos padrões da legislação brasileira, enquanto que os teores de Cu, Mn e Zn determinados foram muito diferentes daqueles descritos no rótulo.

The objective of this work was to evaluate the microbiological and physicochemical quality of UHT whole milk commercialized in the State of Rio Grande do Sul, during the winter and spring of 2009. Four samples of 10 marketed marks were collected in each period. Of these, two of each mark was destined for microbiological analyses and the others two for physicochemical analyses. For the microbiological analyses, the samples were incubated in their original packages at 36±1ºC for 7 days before the analyses were carried out. These analyses, that were carried out in duplicate, were: Most likely number of coliforms at 35˚C and 45˚C; moulds and leavenings count; staphylococcus coagulase positive count; Salmonella research; viable strict and facultative aerobic mesophyle microorganisms standard count; viable aerobic mesophyle microorganisms capable of causing alteration in UHT liquid lactic products count; Bacillus sporothermodurans presence; total aerobic thermophyle and Flat-Sour spore count, that evidences the presence of Geobacillus stearothermophilus and Bacillus coagulans. The physicochemical analyses, carried out in triplicates were: fat, acidity, non fat dry extract, protein, density, cryoscopy and fatty acids profile. The results were analyzed using the SPSS program, version 13.0. For the microbiological analyses, the averages and the mean deviations were obtained. The physicochemical analyses were submitted to the analysis of variance (ANOVA) and the differences were analyzed by the Tukey test with a level of 5% of probability. The ten marks of UHT whole milk analyzed were within the standard microbiological values in effect for the microorganisms that were analyzed. The physicochemical parameter were evaluated partially attended the specifications of the Technical Regulation of Identity and Quality of UHT Milk in relation to that in disagreement 60% in winter and 80% in spring. A prevalence of miristic, palmitic, stearic and oleic fatty acids was observed with significant differences between the marks. It can be concluded that, although some physicochemical parameters were not in accordance with the standards of identity and quality, the ten UHT whole milk commercialized in the State of Rio Grande do Sul attends the specifications related to the microbiological quality, indicating that it is a safe product from the sanitary point of view. / Este trabalho teve por objetivo avaliar a qualidade microbiológica e físico-química do leite UHT integral comercializado no Rio Grande do Sul, durante o inverno e primavera de 2009. Foram coletadas quatro amostras de 10 marcas comerciais, em cada período, destas, duas foram destinadas as análises microbiológicas e duas às análises físico-químicas. Para as análises microbiológicas, as amostras foram incubadas em suas embalagens originais a 36±1ºC por 7 dias, antes do início das análises. Estas análises foram realizadas em duplicata, sendo analisado o número mais provável de coliformes a 35˚C e 45˚C, contagem de bolores e leveduras, contagem de estafilococos coagulase positiva, pesquisa de Salmonela, contagem padrão de microrganismos mesófilos aeróbios estritos e facultativos viáveis, contagem de microrganismos mesófilos aeróbios viáveis capazes de causar alteração em produtos lácteos líquidos UHT, presença de Bacillus sporothermodurans e a contagem de esporos de termófilos aeróbios totais e Flat-Sour que evidenciam a presença de Geobacillus stearothermophilus e Bacillus coagulans. As análises físico-químicas de gordura, acidez, extrato seco desengordurado, proteína, densidade, crioscopia e o perfil de ácidos graxos foram realizados em triplicata. Os resultados foram analisados utilizando o programa SPSS versão 13.0, para as análises microbiológicas foram calculadas as médias e o desvio padrão e as análises físico-químicas foram submetidas à análise de variância (ANOVA) e a diferença analisada pelo teste de Tukey, nível de 5% de probabilidade. As dez marcas de leites UHT integral analisadas apresentaram-se dentro dos padrões microbiológicos vigentes, para os microrganismos estudados. Os parâmetros físico-químicos avaliados atenderam parcialmente as especificações do Regulamento Técnico de Identidade e Qualidade do Leite UHT, apresentando 60% e 80% dos resultados em desacordo no inverno e na primavera, respectivamente. Houve prevalência dos ácidos graxos mirístico, palmítico, esteárico e oléico com diferenças significativas entre as marcas. Pode-se concluir que, apesar de alguns parâmetros físico-químicos não terem atendido aos padrões de identidade e qualidade, as dez marcas de leite UHT integral comercializado no Rio Grande do Sul atendem as especificações quanto à qualidade microbiológica, demonstrando ser um produto seguro do ponto de vista sanitário.

Objective knowledge about quantity, composition and physicochemical characteristics of municipal solid waste (MSW) in the Czech Republic will form the basis for decision- making when considering processing facilities or regional waste management systems. As the country continues to streamline its legislation to the European Union's solid waste mandates, the results of these studies were employed by the Czech Ministry of Environment to optimise the national waste management strategy. This doctoral thesis focuses on the composition of MSW, primarily the mixed MSW from three types of households in the Czech Republic (urban, mixed and rural) differentiated by their heating methods and possibility of waste disposal. The respective experimental work and data-collection took place in years 2008 and 2009. Methodology used in the analyses is based on the sieve analysis of mixed MSW within predetermined grain size fraction and on the final manual sorting of the waste by material categories. The physicochemical characteristics were measured according to the standard analysis methods. The composition of mixed MSW in urban and mixed households are similar. Some of the biggest differences were found in the quantities of certain subsample categories, especially fine fraction (matter smaller than 8 mm), between...

Ce travail de thèse concerne l'évaluation biologique et physico-chimique de deux biomatériaux : verre pure associé au risedronate (46S6-xRIS) et une vitrocéramique poreuse dopée avec l'oxyde de zinc et le nitrure de titane noté 46S6-10Zn-2Ti. Le premier est un matériau hybride composé du verre (46S6) et d'un bisphosphonate le risedronate à différentes teneurs (xRIS) avec x= 8, 12 et 20%. Le deuxième est une vitrocéramique ayant une porosité créée par l'élimination de N après calcination. Les analyses physico-chimiques après les tests in vitro du 46S6-xRIS montrent une modification de la cinétique de la bioactivité de ces composites selon la quantité de risedronate ajoutée au 46S6. Les analyses in vivo ont été aussi menées sur le 46S6-10Zn-2Ti. Cette vitrocéramique a été implantée dans des condyles fémoraux de rattes ostéoporotiques, phénomène créé par l'irradiation des rattes à différentes doses de rayons γ. L'investigation biologique après irradiation montre un déséquilibre entre la peroxydation lipidique et les enzymes antioxydants. L'implantation en site osseux avec le 46S6-10Zn-2Ti a permis la restauration de cette balance. L'étude histologique montre le rétablissement du tissu osseux. Cependant, celui ci décroit avec l'augmentation de la dose des rayons gamma. Pour l'exploration physico-chimique, plusieurs techniques complémentaires ont été utilisées pour évaluer la cinétique d'ossification. La bioconsolidation de notre vitrocéramique a été également évaluée après implantation chez des lapins. Le microscanner (mCT) montre la résorption du 46S6-10Zn-2Ti et l'osséo-intégration des cellules osseuses dans les pores du bio-implant alors que, l'étude histologique montre que le 46S6-10Zn-2Ti est presque totalement dégradé et remplacé par le tissue osseux. Le MEB met en évidence la dégradation du 46S6-10Zn-2Ti et son remplacement par un dépôt apatitique. Les spectres MAS-RMN du ³¹P et u ²⁹Si illustrent la dégradation progressive du 46S6-10Zn-2Ti en faveur du développement de l'apatite biologique. / This work focuses on the biological and physicochemical evaluations of two biomaterials: a bioactive glass associated to risedronate (46S6-xRIS) and a porous glass ceramic doped with zinc oxide and titanium nitride noted 46S6-10Zn-2Ti. The first is a hybrid material composed of bioactive glass (46S6) and a bisphosphonate, the risedronate with different contents (xRIS) with x=8, 12 and 20%. The second is a ceramic glass having a porosity, which has been created following the elimination of N after heating. Physicochemical analysis after the in vitro essays of 46S6-xRIS show the modification of the bioactivity kinetic of these composites proportional to the quantity of risedronate added to the 46S6. The in vivo analyses were also conducted in the 46S6-10Zn-2Ti. This glass ceramic was implanted in the femoral condyles of osteoporotic rats. This phenomenon was created after its irradiation at different doses of γ-rays. The biological investigations after irradiation show an imbalance between the lipid peroxidation and antioxidants enzymes. The implantation of 46S6-10Zn-2Ti in bone tissue restored the oxidative balance. The histological study manifests the restoration of bone tissue. However, this restoration decreased with the rising of γ-rays doses. For the physiochemical exploration, several complementary techniques were used to evaluate the kinetic of ossification. The porous glass ceramic was evaluated also in the bioconsolidation process after implantation in rabbit. The X-ray Micro-Computer Tomography (mCT) shows the resorption of the 46S6-10Zn-2Ti and the osseointegration of bones cells in the biomaterial pores. Moreover, the histological study illustrates that the degradation and the resoption of the 46S6-10Zn-2Ti is almost total. The SEM highlights the degradation of the 46S6-10Zn-2Ti and its replacement by an apatitic deposit. The MAS-NMR spectra of ³¹P and of ²⁹Si illustrate a progressive degradation of 46S6-10Zn-2Ti in favor of the development of a biological apatite.

La patate douce est un tubercule appartenant à l'ordre des polémoniales et à la famille des convolvulacées. Il contient de l’amidon, qui est l’élément principal, des dextrines, du ß-carotène, puis d’autres éléments nutritifs en quantités variables. L’objectif de la thèse a été de valoriser la patate douce sous forme de farines et de mettre en évidence les potentialités technologiques de ces farines. Deux études complémentaires ont été réalisées au cours de ce travail de thèse, la première concerne l’étude de l’impact des prétraitements thermiques et chimiques sur les propriétés physicochimiques, thermiques, rhéologiques et fonctionnelles des farines issues de patates douces ayant : TPD (tranche de patate douce non prétraitée), TPDCaCl2 (tranche de patate douce prétraitée au CaCl2) et enfin TPDB (tranche de patate douce prétraitée par blanchiment). Il en résulte une légère augmentation de la teneur en sucres réducteurs dans les farines TPDCaCl2 par rapport aux farines TPDB et TPD. Cependant, la valeur de L* (luminance) dans la farine TPDB était inférieure à celles des farines TPDCaCl2 et TPD. La teneur en calcium était relativement élevée dans la farine TPDCaCl2 (120,6 mg/100g) par rapport aux farines TPD et TPDB (respectivement, 77,8 et 67,6 mg/100g). Les valeurs d’enthalpie de gélatinisation et de module élastique (G’) étaient supérieures dans la farine TPDCaCl2. La capacité de gonflement était élevée dans les farines blanchies. Il a également été constaté une légère augmentation de la constante d'énergie de liaison d'eau du modèle BET dans les farines traitées au CaCl2 et une augmentation marquée pour les farines blanchies. De cette étude, on déduit que les farines traitées au CaCl2 possèdent les propriétés physicochimiques les plus intéressantes pour une application en panification et dans la formulation alimentaire. Dans une seconde étude, les essais de panification ont été réalisés avec différents taux d’incorporation à la farine de blé (0, 10, 15, 20, 25 et 30 %) des farines de patate douce traitées au CaCl2 afin de déterminer le taux d’incorporation optimal permettant de réaliser un compromis entre l’amélioration des propriétés nutritionnelles et la diminution des propriétés rhéologiques de la pâte à pain, suite à l’incorporation de farine de patate douce. Les paramètres texturaux des pâtes ont été déterminés. Il en résulte une diminution de la cohésion, la valeur de a* (échelle de couleurs rouge-vert) a augmenté avec l’augmentation du taux de substitution, contrairement aux valeurs de la luminance L* qui ont diminué. Finalement, la farine de patate douce pouvait être incorporée dans une formulation de panification jusqu’à 25 % sans dépréciation notable des qualités organosensorielles des pains / Sweet potato is an edible tuber belonging to the order of Solanales and Convolvulaceae family. It contains starch, which is the main component, dextrins, ß-carotene, and other nutrients in varying amounts. The thesis aimed promoting the use of sweet potato as flour by highlighting its nutritional potential. Two complementary studies were carried out in this thesis work, the first concerned the study of the impact of thermal and chemical pretreatments on physicochemical, thermal, rheological, and functional properties of sweet potatoes flours obtained after different pretreatments : TPD (unpretreated sweet potato slices), TPDCaCl2 (CaCl2- pretreated sweet potato slices) and finally TPDB (bleached sweet potato slices). These results show a slight increase in reducing sugar content in TPDCaCl2flour compared to TPDB and TPD flours. However, the value of L* (luminance) in the TPDB flour was below the ones ofTPDCaCl2 and TPD flours. The calcium content was relatively high in TPDCaCl2 flour (120.6 mg / 100 g) compared to TPD and TPDB flours (respectively, 77.8 and 67.6 mg / 100g). The gelatinization enthalpy and elastic modulus (G’) were higher in the TPDCaCl2 flour. The swelling capacity was high in bleached flour. It was also noticed a slight increase in the water binding energy constant of the BET model in CaCl2-pretreated and blanched. In this study, it was deduced that the flours pretreated with CaCl2 have physicochemical properties interesting for bakery and food formulation applications. In the second part of the thesis study, baking tests were carried out with different levels of incorporation to wheat flour (0, 10, 15, 20, 25 and 30 %) of the CaCl2-pretreated sweet potato flour in order to determine the optimal incorporation level allowing the compromise between improved nutritional properties and the decreased rheological properties of the dough, due to the sweet potato flour incorporation. Textural parameters of doughs were determined. This resulted in a decrease in cohesion and an increase in the value of a* (red - green color scale) with increasing the degree of substitution, in contrast to the luminance L * values which felt. Finally, sweet potato flour could be incorporated into a bread formulation up to 25 % without significant impairment of sensory organic qualities of bread

Les diodes organiques électroluminescentes (OLEDs), dans lesquelles l’émission de couleur provient de la fluorescence de molécules organiques, représentent une évolution de la technologie des diodes électroluminescentes (LED) classiques. Les OLEDs phosphorescentes (PhOLEDs) permettre d’atteindre des rendements plus élevée que les OLEDs, en utilisant comme couche émissive un couple « matériau organique/dopant phosphorescent ». Ce travail porte sur la synthèse et l'étude de nouvelles molécules à haut état triplet, pour des applications comme matrices hôtes dans des PhOLEDs bleues. Après une introduction à ce domaine novateur, la synthèse de nouveaux semi-conducteurs organiques dérivés de l’architecture 2π-1spiro et l’analyse détaillée des propriétés physico-chimiques sont présentées. Les performances de PhOLEDs bleues utilisant ces nouvelles matrices sont alors décrites et montrent l’intérêt du design de ces nouvelles molécules hôtes. / Organic light emitting diodes (OLEDs) in which light is emitted from fluorescence pathway of an organic molecule, represent an evolution of the light emitting diode (LED) technology. Phosphorescent OLEDs (PhOLEDs) which combine in the emitting layer an “organic host doped with a guest phosphor”, may reach theoretically higher performances than OLEDs. This work is focused on the synthesis and the study of new organic compounds with high triplet state energy, which will be used as host material in blue PhOLEDs. After an introduction of this important field of organic electronics, the synthesis of new organic semi-conductors based on the 2π-1spiro architecture and the detailed analysis of their physicochemical properties through a structure/properties relationship study are presented. The performances of blue PhOLEDs using these matrices are then described and show the great interest of the new host designs.

No description available.

L'objectif de cette thèse a été de mesurer comment les modifications des régimes hydrologiques, plus particulièrement les exondations, régissent 1) certains aspects du fonctionnement des zones humides, 2) l'organisation et la dynamique à court terme des communautés végétales aquatiques et 3) la survie et la réponse plastique des végétaux aquatiques. Cette thèse aborde les questions à des échelles spatio-temporelles différentes. Premièrement, à l'échelle de la décennie, j'ai mesuré la conséquence de la baisse de la hauteur d'eau des zones humides péri-fluviales sur leur physico-chimie. Deuxièmement, à l'échelle de la saison, j'ai mesuré l'influence des caractéristiques sédimentaires des zones humides sur la réponse à court terme des communautés végétales à l'exondation. Enfin, à l'échelle de quelques semaines, je me suis intéressée à l'aptitude des espèces d'angiospermes aquatiques à mettre en place un ajustement plastique face à l'exondation, en conditions expérimentales de laboratoire et in situ, j'ai recherché les déterminismes de cette réponse (écologiques, morphologiques, phylogénétiques). En termes de caractéristiques physico-chimiques des eaux de surface, l'étude sur 15 ans de la dynamique de zones humides péri-fluviales subissant des exondations, ne conclue pas, comme cela est habituellement décrit dans la littérature, à une augmentation de la teneur en nutriments de la masse d'eau, mais plutôt des changements suggérant des variations du fonctionnement hydrogéologique des zones humides, en faveur d'une plus grande influence de la nappe de versant dans leur alimentation. La réponse in situ des communautés végétales à l'exondation diffère selon le type de sédiment. La résistance et la résilience des communautés décroissent toutes deux avec la capacité de rétention d'eau du sédiment. La capacité des plantes aquatiques à tolérer l'exondation, en conditions expérimentales, semble différer selon leur position phylogénétique, mais pas selon leur forme de croissance (rosettes ou caulescentes) / The objective of this thesis was to measure how changes in hydrological regimes, particularly dewatering govern 1) aspects of the functioning of wetlands, 2) the organization and short-term dynamics of aquatic plant communities and 3 ) survival and plastic response of aquatic plants. This thesis addresses issues at different spatial and temporal scales. First, at the decade scale, I measured the effect of water-level decreases in riverine wetlands on their physico-chemistry characteristics. Second, at the season scale, I measured the influence of sedimentary characteristics of wetlands on short-term response of plant communities to dewatering. Finally, at the scale of a few weeks, I was interested in the ability of aquatic angiosperm species to develop a plastic adjustment to dewatering, in experimental laboratory conditions and in situ, and I looked determinism of this response (ecological, morphological, phylogenetic). In terms of physico-chemical characteristics of surface waters, the 15- year study of the dynamics of riverine wetlands undergoing dewatering, not reached, as is usually described in the literature, with an increase of water body nutrient contents, but rather changes suggesting variations of the hydrogeological functioning of wetlands in favor of a greater influence of the hillslope groundwater table in their water supply. In situ response of plant communities to dewatering differs according to sediment type. Both, resistance and resilience of communities decrease with the sediment water retention capacity. The ability of aquatic plants to tolerate dewatering, in experimental conditions, seems to differ according to their phylogenetic position, but not according to their growth form (rosettes or caulescentes). Species tolerating dewatering show phenotypic adjustments such as denser aerial organs and high plasticity of the leaves, which may explain the maintenance of a similar growth rate in terrestrial and aquatic conditions in these species