As membranas de troca aniônica são uma alternativa promissora para o desenvolvimento de eletrólitos mais eficientes para células a combustível alcalinas. Em geral, as membranas de troca aniônica são ionômeros capazes de conduzir íons hidroxila devido aos grupos quaternário de amônio e têm como característica elevado pH equivalente. Com o objetivo de desenvolver membranas aniônicas química e termicamente estáveis, com satisfatória condutividade iônica para aplicação em células a combustível alcalinas, as membranas aniônicas foram sintetizadas a partir de polímeros base de polietileno de baixa densidade (LDPE), polietileno de ultra alto peso molecular (PEUHMW), poli(etileno-co-tetrafluoroetileno) (PETFE) e poli(tetrafluoroetilleno-co-hexafluoroetileno) (PFEP) previamente irradiados nas fontes de radiação gama de 60Co ou com feixe de elétrons, para enxertia do monômero de estireno e funcionalizados com trimetilamina para incorporação dos grupos quaternário de amônio. As membranas resultantes foram caracterizadas por espectroscopia de ressonância paramagnética eletrônica (EPR), espectroscopia Raman, termogravimetria (TG), espectroscopia de impedância eletroquímica (EIS), além da determinação do grau de enxertia, capacidade de absorção de água por gravimetria e capacidade de troca iônica, por titulação. As membranas sintetizadas com os polímeros LDPE e UHMWPE pré-irradiados a 70 kGy com feixe de elétrons e armazenadas a baixa temperatura (-70 °C) por até 10 meses, mostraram resultados de condutividade iônica, quando na forma (OH-), de 29 mS.cm-1 e 14 mS.cm-1 a 65 °C, respectivamente. Os filmes de PFEP irradiados no processo simultâneo mostram níveis de enxertia insuficientes para a síntese de membranas aniônicas, necessitando maiores estudos para aperfeiçoar os processos de irradiação e enxertia. As membranas baseadas em PETFE, pré-irradiadas a 70 kGy com feixe de elétrons e armazenadas a baixa temperatura (-70 °C) por até 10 meses, mostraram maior condutividade iônica, quando na forma hidroxila (OH-), com valores de condutividade iônica entre 90 mS.cm-1 e 165 mS.cm-1 na faixa de temperatura entre 30 e 60 °C. Estes resultados mostraram que membranas de LDPE, UHMWPE e PETFE são eletrólitos promissores para a aplicação em células a combustível alcalinas. / Anion Exchange Membranes (AEMs) are a promising alternative to the development of more efficient electrolytes for alkaline fuel cells. In general, the AEMs are ionomeric membranes able to conduct hydroxide ions (OH-) due to the quatermary ammonium groups, which confer high pH equivalent to the AEM. In order to develop alkaline membranes with high chemical and thermal stability, besides satisfactory ionic conductivity for alkaline fuel cells, membranes based on low density polyethylene (LDPE), ultrahigh weight molecular weight polyethylene (UHWHPE), poly(ethylene-co-tetrafluoroethylene) (PETFE) and poly(hexafluoropropylene-co-tetrafluoroethylene) (PFEP) previously irradiated by using 60Co gamma and electron beam sources, have been synthesized by styrene-grafting, and functionalized with trimethylamine to introduced quaternary ammonium groups. The resulting membranes were characterized by electron paramagnetic resonance (EPR), Raman spectroscopy, thermogravimetry (TG) and electrochemical impedance spectroscopy (EIS). The determination of the grafting degree and water uptake were conducted by gravimetry and ion exchange capacity, by titration. The membranes synthesized with PELD and PEUHMW polymers pre-irradiated at 70 kGy and stored at low temperature (-70 °C), up to 10 months, showed ionic conductivity results, in hydroxide form (OH-), of 29 mS.cm-1 and 14 mS.cm-1 at 65 °C, respectively. The PFEP polymers irradiated by the simultaneous process showed insufficient grating levels for the membrane synthesis, requiring more studies to improve the irradiation and grafting process. The styrene-grafted PETFE membranes, pre-irradiated at 70 kGy and stored at low temperature (-70 °C), up to 10 months, showed ionic conductivity results, in hydroxide form (OH-), of 90 mS.cm-1 to 165 mS.cm-1, in the temperature range 30 to 60 °C. Such results have demonstrated that LDPE, UHMWPE and PETFE based AEMs are promising electrolytes for alkaline fuel cell application.

Catecol e catecolaminas foram ensaiados sobre as atividades NADPH e NADH oxidásica dos microssomos. Quantidades catalíticas de adrenalina aumentam de duas a três vezes a velocidade de oxidação do NADPH, após um pequeno período de indução. O efeito da adrenalina é suprimido pela superóxido dismutase, se a enzima é adicionada antes de iniciada a reação. O efeito catalítico é atribuído a dois produtos de oxidação da adrenalina pelo íon superóxido; à quinona, produto de oxidação de dois elétrons e ao adrenocromo, produto de oxidação de quatro elétrons. Provavelmente, o adrenocromo reoxida a NADPH citocromo c redutase, e a quinona formada reage com oxigênio, regenerando adrenocromo. A adrenalina não mostrou qualquer efeito sobre a atividade NADH oxidásica, nem sobre a atividade NADPH oxidásica, estimulada por menadiona. Provavelmente, durante estes processos, dois elétrons são transferidos simultaneamente ao oxigênio. Catecol e catecolaminas duplicam a velocidade de oxidação do NADH em presença de quantidades catalíticas de NADH-citocromo b5 redutase e citocromo b5. Este resultado sugere a formação do íon superóxido, durante a autoxidação do citocromo b5. Catecol e p-hidroquinona promovem, cataliticamente, a oxidação da oxihemoglobina e oximioglobina à forma ferri. A velocidade de oxidação da oxihemoglobina mostra dependência de primeira ordem em relação à concentração de hemeproteína e de meia ordem em relação ao difenol ; contudo a altas concentrações dos catalisadores observa-se saturação, com valores de Vmáx similares para ambos os difenóis. É proposto que uma quinona , inicialmente formada, oxida a oxihemeproteína com liberação de oxigênio; por sua vez, a semiquinona oxida uma segunda molécula de oxihemeproteína, sendo que o oxigênio ligado recebe dois elétrons. Exceto para o caso da oximioglobina, que é mais reativa, a forma reduzida do catalisador deve estar presente para se opor ao desaparecimento da semiquinona por dismutação. Desde que se observa a liberação de oxigênio, esperada para a formação de água, o sistema pode ser considerado modelo de oxidase terminal. Infere-se tentativamente, que a oxihemoglobina tem estrutura HbFe2+ ...O2, e que a velocidade da oxidação catalisada é limitada pela velocidade de produção da verdadeira forma reativa, a estrutura ferri-superóxido, HbFe3+...O-2. / Catechol and catecholamines have been assayed upon the microsomal NADPH and NADH oxidase activities. Adrenaline shows a catalytic effect on the NADPH oxidation characterized by a small lag. The two-to three fold increase in rate can be supressed by dismutase if the enzyme is added before superoxide the reaction begins. The catalytic effect is ascribed to two products of adrenaline oxidation by the superoxide ion; to the quinone, the two electron oxidation product, and to the adrenochrome, the four electron oxidation product. Presumably, the adrenochrome reoxidizes the NADPH-cytochrome c reductase, and the formed quinone reacts with oxygen and regenerates the adrenochrome. Adrenaline neither changed, the NADH oxidase activity nor the menadione-stimulated NADPH oxidase activity. Presumably in these processes, two electrons are simultaneously transferred to the oxygen. Catechol and catecholamines doubled the rate of autoxidation of NADH in the presence of catalytic amounts of NADH-cytochrome b5 reductase and cytochrome b5 This result suggests superoxide ion formation in the autoxidation of the cytochrome. Catechol and p-hydroquinone catalytically promote the oxidation of oxyhemoglobin and oxymyoglobin to the ferri-form. Kinetic data for oxyhemoglobin oxidation indicates a first-order dependence upon the hemoprotein concentration and half-order dependence upon diphenol; however at high catalyst concentration, saturation is observed with similar Vmax values for both diphenols despite the difference in reactivity. It is proposed that initially formed quinone oxidizes the hemoprotein with oxygen release; in turn the semiquinone oxidizes a second molecule of hemoprotein and regenerates the quinone, with the bound oxygen acquiring two electrons. Except for the more reactive oxymyoglobin, the reduced form of the catalyst must be present to oppose semiquinone disappearance by dismutation, Since the expected release of 02 for water formation is observed, the system may be considered a model for terminal oxidase. It is tentatively inferred that oxyhemoglobin has the structure HbFe2+...02 and that the rate of the catalyzed oxidation is limited by the rate of generation of the true reacting form, the superoxide ferri structure, HbFe3+...0-2.

As membranas de troca aniônica são uma alternativa promissora para o desenvolvimento de eletrólitos mais eficientes para células a combustível alcalinas. Em geral, as membranas de troca aniônica são ionômeros capazes de conduzir íons hidroxila devido aos grupos quaternário de amônio e têm como característica elevado pH equivalente. Com o objetivo de desenvolver membranas aniônicas química e termicamente estáveis, com satisfatória condutividade iônica para aplicação em células a combustível alcalinas, as membranas aniônicas foram sintetizadas a partir de polímeros base de polietileno de baixa densidade (LDPE), polietileno de ultra alto peso molecular (PEUHMW), poli(etileno-co-tetrafluoroetileno) (PETFE) e poli(tetrafluoroetilleno-co-hexafluoroetileno) (PFEP) previamente irradiados nas fontes de radiação gama de 60Co ou com feixe de elétrons, para enxertia do monômero de estireno e funcionalizados com trimetilamina para incorporação dos grupos quaternário de amônio. As membranas resultantes foram caracterizadas por espectroscopia de ressonância paramagnética eletrônica (EPR), espectroscopia Raman, termogravimetria (TG), espectroscopia de impedância eletroquímica (EIS), além da determinação do grau de enxertia, capacidade de absorção de água por gravimetria e capacidade de troca iônica, por titulação. As membranas sintetizadas com os polímeros LDPE e UHMWPE pré-irradiados a 70 kGy com feixe de elétrons e armazenadas a baixa temperatura (-70 °C) por até 10 meses, mostraram resultados de condutividade iônica, quando na forma (OH-), de 29 mS.cm-1 e 14 mS.cm-1 a 65 °C, respectivamente. Os filmes de PFEP irradiados no processo simultâneo mostram níveis de enxertia insuficientes para a síntese de membranas aniônicas, necessitando maiores estudos para aperfeiçoar os processos de irradiação e enxertia. As membranas baseadas em PETFE, pré-irradiadas a 70 kGy com feixe de elétrons e armazenadas a baixa temperatura (-70 °C) por até 10 meses, mostraram maior condutividade iônica, quando na forma hidroxila (OH-), com valores de condutividade iônica entre 90 mS.cm-1 e 165 mS.cm-1 na faixa de temperatura entre 30 e 60 °C. Estes resultados mostraram que membranas de LDPE, UHMWPE e PETFE são eletrólitos promissores para a aplicação em células a combustível alcalinas. / Anion Exchange Membranes (AEMs) are a promising alternative to the development of more efficient electrolytes for alkaline fuel cells. In general, the AEMs are ionomeric membranes able to conduct hydroxide ions (OH-) due to the quatermary ammonium groups, which confer high pH equivalent to the AEM. In order to develop alkaline membranes with high chemical and thermal stability, besides satisfactory ionic conductivity for alkaline fuel cells, membranes based on low density polyethylene (LDPE), ultrahigh weight molecular weight polyethylene (UHWHPE), poly(ethylene-co-tetrafluoroethylene) (PETFE) and poly(hexafluoropropylene-co-tetrafluoroethylene) (PFEP) previously irradiated by using 60Co gamma and electron beam sources, have been synthesized by styrene-grafting, and functionalized with trimethylamine to introduced quaternary ammonium groups. The resulting membranes were characterized by electron paramagnetic resonance (EPR), Raman spectroscopy, thermogravimetry (TG) and electrochemical impedance spectroscopy (EIS). The determination of the grafting degree and water uptake were conducted by gravimetry and ion exchange capacity, by titration. The membranes synthesized with PELD and PEUHMW polymers pre-irradiated at 70 kGy and stored at low temperature (-70 °C), up to 10 months, showed ionic conductivity results, in hydroxide form (OH-), of 29 mS.cm-1 and 14 mS.cm-1 at 65 °C, respectively. The PFEP polymers irradiated by the simultaneous process showed insufficient grating levels for the membrane synthesis, requiring more studies to improve the irradiation and grafting process. The styrene-grafted PETFE membranes, pre-irradiated at 70 kGy and stored at low temperature (-70 °C), up to 10 months, showed ionic conductivity results, in hydroxide form (OH-), of 90 mS.cm-1 to 165 mS.cm-1, in the temperature range 30 to 60 °C. Such results have demonstrated that LDPE, UHMWPE and PETFE based AEMs are promising electrolytes for alkaline fuel cell application.

La surexploitation des ressources de la planète est aujourd’hui une problématique de premier ordre, et fait du remplacement des sources non renouvelables, d'énergie et de matières premières, l’un des défis majeurs du XXIe siècle. Dans cet objectif, les lignines, par leur disponibilité et leur biocompatibilité, apparaissent comme l’une des alternatives aux ressources fossiles. C’est dans ce contexte que le Laboratoire PEIRENE a décidé de mener ce travail de thèse portant sur le développement de nouveaux matériaux photosensibles à base de lignines modifiées. Dans ce but, trois lignines d’origines différentes ont été acétylées. Leur étude par spectroscopie RPE a révélé que le blocage de leurs fonctions antioxydantes augmente considérablement la quantité d’espèces réactives de l’oxygène qu’elles sont capables de générer sous irradiation lumineuse, permettant ainsi d’envisager l’utilisation de ce biopolymère modifié dans de nombreux domaines tels que le traitement photodynamique antimicrobien. Afin de les rendre hydrodispersibles et d’élargir ainsi leur champ d’applications, ces matériaux aux propriétés prometteuses ont été mis sous forme de nanoparticules puis, leur comportement photosensible a été lui aussi évalué par spectroscopie RPE. Il a ainsi été démontré qu’une fois dispersées dans l’eau sous la forme de nanoparticules, les lignines acétylées étaient toujours capables de produire de l’oxygène singulet sous irradiation lumineuse. Cette activité, qui n’a pas encore été reportée dans la littérature à notre connaissance, reste cependant assez restreinte et nécessite donc d’être améliorée. Afin d’élargir le domaine du spectre solaire permettant leur activation, un photosensibilisateur a par ailleurs été associé à ces nano-objets par encapsulation et par greffage covalent. L’ensemble des résultats découlant de ces travaux permettent d’envisager le développement de systèmes à base de nanoparticules de lignines acétylées dans de nombreux domaines, notamment pharmaceutique et phytosanitaire. / The overexploitation of the planet's resources is nowadays a major problem and makes the replacement of non-renewable sources of energy and raw materials, one of the major challenges of the XXIe century. For this purpose, lignins, by their availability and their biocompatibility, appear as one of the alternatives to fossil resourcesIn this context, the PEIRENE Laboratory decided to carry out this PhD work on the development of new photosensitive materials based on modified lignins. For this purpose, three lignins from different origin were acetylated. Their study by EPR spectroscopy revealed that blocking their antioxidant functions considerably increases the quantity of reactive oxygen species they are able to generate under light irradiation. Thus it is possible to envisage the use of this modified biopolymer in many areas such as antimicrobial photodynamic therapy. In order to make them water-dispersible and thus to widen their field of applications, these materials with promising properties were put in the form of nanoparticles. Their photosensitive behavior has been also valuated by EPR spectroscopy. It has been demonstrated that once dispersed in water in the form of nanoparticles, the acetylated lignins were still capable of producing singlet oxygen under light irradiation. This activity, which has not yet been reported in the literature to our knowledge, however, remains quite limited and therefore needs to be improved. In order to widen the range of the solar spectrum allowing their activation, a photosensitizer has also been associated with these nano-objects by encapsulation and covalent grafting. The results of these studies make possible to envisage the development of systems based on acetylated lignins nanoparticles in in many field, in particular pharmaceutical and phytosanitary.

Les recherches menées au cours de cette thèse ont pour but de converger vers la synthèse de molécules énergétiques, possédant un squelette polyazoté, destinées à la propulsion spatiale ou militaire. En effet, les systèmes propulsifs utilisés à l’heure actuelle reposent sur des technologies, certes fiables, mais souffrant de limites de performance voire d’incompatibilité quant à la réglementation européenne REACH. Il devient nécessaire, pour que les lanceurs européens conservent leur première position mondiale dans le domaine de la mise en orbite de satellites publics ou privés, de se doter de nouveaux propergols plus performants. C’est ainsi que nous avons orienté ce travail vers la synthèse de composés appartenant à la famille des « HEDM » (High Energetic Density Material), composés possédant en rupture technologique avec les solutions actuelles, et dont le développement est attendu à l’horizon 2050. Dans le cadre de cette thèse, deux cibles d’intérêt ont été identifiés : l’anion pentazolate, molécule strictement azotée aromatique de formule N5-, et le cyclopentazane, molécule inédite à ce jour, de formule N5H5. Dans une première partie nous avons étudié la synthèse de la synthèse et l’étude de divers arylpentazoles, ainsi que des voies d’oxydation et de réduction de ces précurseurs menant à l’obtention de l’anion pentazolate Puis, dans un second temps nous nous sommes intéressés aux synthèses et aux études de stabilités de composés polyazotés de type triazane et azimine. Ces composés ont ensuite été utilisés à des réactions de cycloadditions [3+2] menant à la synthèse du cyclopentazane. Enfin, nous avons regardé les différents modes de complexation possible entre ces composés polyazotés et des complexes métalliques / The research carried during this PhD aims to synthesis new compounds with polynitrogen-backbone suitable for spacecraft or military propulsion. Indeed, the actual spacecraft uses a technology which is reliable, but with some limitation with their energetic efficiency and to satisfy the REACH regulation. It is necessary, for the Europeans launcher to stay at the first position in public or private satellites launch world wild, to find new and more efficient propellant. So, this work was focused on the synthesis of “HEDM” (High Energetic Density Material) compounds, which possess much higher propulsive features than the actual propellants. This could lead to a breakthrough in spacecraft propulsion in the next 30 years.For this PhD work two compounds of interest were identified: the pentazolate anion, which is an all nitrogen aromatic compound with a formula of N5-, and the cyclopentazan, which is an original polynitrogen compound with a formula of N5H5. First, we focused our work on the synthesis of various arylpentazoles followed by oxidative or reductive ways which lead to the pentazolate anion. Secondly, we synthesised and the studied the stability of polynitrogen-based compound, triazanes and azimines. Those compounds were then used in trials of cycloadditions which will lead to the cyclopentazan. Finally, we studied various way of complexing our polynitrogen-compound with various metallic complexes

This thesis is comprised of three parts. The first part concerns the investigation of the topochemical reduction of LaSrNiRuO₆ in order to prepare LaSrNiRuO₄ via anion deintercalation. The second part discusses the oxide-for-hydride anion exchanges performed in SrV_1-xTi_xO₃, and the resulting SrV_1-xTi_xO_2-yH_1+y reduction products. Finally, the results from redox-neutral topochemical cation exchange reactions conducted in the three-dimensional perovskite structure of NaTaO₃ are presented along with the characterisation of a novel product of composition Ni_0.5TaO₃. The topochemical reduction of LaSrNiRuO₆ using CaH2 was carried out to produce a novel extended oxide phase with composition LaSrNiRuO₄. This phase is composed of sheets of apex-linked Ni¹⁺O₄ and Ru²⁺O₄ squares in a checkerboard ordered arrangement. To the best of our knowledge, this material is the first example of a B-cation ordered infinite-layer oxide phase. The low oxidation states of the transition-metal cations are confirmed by DFT calculations from which a spin moment S = ½ is determined for the nickel while the ruthenium centres adopt an intermediate-spin S = 1 configuration. LaSrNiRuO4 behaves paramagnetically at room temperature. However, upon cooling (T < 250 K) a phase transition is observed in which the nickel spins interact ferromagnetically, while the ruthenium cations appear to undergo a change in spin configuration to a diamagnetic spin state. A possible explanation is given for this observation based on an ordered arrangement of local Jahn-Teller distortions. While investigating the preparation of LaSrNiRuO₄, it was observed that different samples of the LaSrNiRuO₆ starting materials exhibited markedly different reactivity. The observed differing reactivity is inconsistent with the crystal structure and composition of the LaSrNiRuO₆ samples, from which all the materials are identical. Careful investigation of the X-ray diffraction data collected from the LaSrNiRuO6 materials revealed that the reactivity of the samples is a consequence of the microstructure. By quenching or slow-cooling the materials during their synthesis, the size of the crystalline domains formed is affected and this in turn is observed to define the extent to which the topochemical deintercalation of oxide anions takes place. A mechanism to explain this effect is presented in which the greater 'plasticity' of small crystalline domains helps to limit the influence of lattice strain during the reaction. Similar with the observations for the LaSrNiRuO₆ phases, it was found that the reactivity of SrV_0.95Ti_0.05O₃ samples towards topochemical oxide-for-hydride exchange is also determined by the characteristics of the starting materials. The cooling rate can lead to phase segregation in SrV_0.95Ti_0.05O₃ samples which in turn affects the reduction behaviour. A modification of the energy profile for the oxide-for-hydride exchange in SrV_1-xTi_xO₃ phases is proposed on the basis of the electronic configuration that the transition-metal cations adopt upon reduction (d²,V³⁺ and d¹,Ti³⁺). Finally, topochemical exchange reactions can also be carried out between cations in complex transition metal oxides when the mobility of the species to be exchanged is sufficiently greater with respect to the host lattice. The preparation of Ni_0.5TaO₃ from exchange of Na⁺ by Ni²⁺ in NaTaO3 represents a synthetic approach not yet widely explored in the long-standing challenge that the preparation of magnetoelectric multiferroic materials represents. The topochemical reactions studied in this work highlight the possibility of directing and modifying the product phases, by tuning features of the reagents. This is in contrast with the limited control available in thermodynamic processes.

Cette étude a pour objectif d’étudier expérimentalement les interactions entre différents anions (chlorure, bromure, nitrate et sulfate) et le silicate de calcium hydraté (C-S-H) afin de construire un modèle thermodynamique capable de prédire cette interaction. Des suspensions de C-S-H synthétisées ont été mises en contact avec différents types de sel (sel de calcium ou d’alcalins). L’influence de la température et de l’incorporation d’aluminium au sein de la structure du C-S-H ont également été prises en compte.L’utilisation d’une méthode d’analyse classique de ce type de système (c’est-à-dire séparation des phases liquide et solide puis analyse de la solution) a révélé ses limites avec, entre autres, une mauvaise reproductibilité des résultats. L’étape de séparation des phases s’est trouvée être à l’origine des difficultés rencontrées.Une seconde méthode d’analyse ne nécessitant pas de filtration des suspensions de C-S-H a été mise au point pour cette étude.Les résultats obtenus ont alors démontrés la non-adsorption des chlorures, nitrates ou bromures par les particules de C-S-H : ces anions n’ont qu’un rôle de compensation de charge au sein de la couche diffuse entourant les particules en suspensions.Les ions calcium (dans le cas d’ajout de sel de calcium) ne s’adsorbent que très faiblement à la surface du C-S-H. Ceci n’est pas influencé par la présence d’aluminium dans la structure. Une température plus faible (5°C) ou plus élevée (40°C) conduit à une adsorption plus faible, voire nulle.L’utilisation d’un modèle thermodynamique de simulation de C-S-H (développé dans une autre étude) a permis de reproduire les résultats expérimentaux obtenus, confirmant donc la validité de ces derniers mais également celle du modèle utilisé. / This project aims to study the interactions between calcium silicate hydrate (C-S-H) and different anions (chlorides, bromides, nitrates and sulfates) in order to build a thermodynamic model and then be predictable. The simplified system CaO-SiO2-H2O is studied by synthesizing C-S-H suspensions and mixing them with different kind of salts (calcium salt or alkali salt). The influence of the temperature and the presence of aluminum in the structure of the C-S-H is also examined.A classical way to investigate this kind of system is to separate the liquid phase from the solid phase in order to analyze them separately. Nevertheless, this step has a large influence on the system, and the experimental results suffer from a really bad reproducibility.Another analysis method has then been developed in order to avoid the separation of the different phases. The results show that there is no adsorption of chlorides, bromides or nitrate on the surface of the C-S-H. They only have a role as a charge compensator in the diffuse layer around the particles in suspension.The calcium cation (in the case of calcium salt addition) can be adsorbed by C-S-H, but in a small quantity. The substitution of silicon by aluminum in C-S-H doesn’t have any influence on this phenomenon. A higher or lower temperature results in a weaker adsorption, even inexistent.Those experimental results have been reproduced by using a thermodynamic model developed in a previous study. Thus, the validity of the experimental part but also the one of the model are confirmed.

La recherche vise à proposer des membranes pour des dispositifs électrochimiques capables d'atteindre le bon compromis en terme de conduction ionique, de stabilité et de longue durée de vie pour une haute efficacité.Nous avons réalisé des membranes échangeuses des protons, d'anions ou amphotères à base de polymères aromatiques stables fonctionnalisés. Des groupes sulfonique on été introduit sur la squelette du PEEK, des groupes d'ammonium sur le PEEK et le PSU ou le deux au même temps pour échanger ensemble des protons et des anions.L'optimisation continue des paramètres de synthèse, le choix des différents polymères et/ou des groupes de fonctionnalisation et l'amélioration des procédures et des traitements des membranes coulée, a conduit à de bons résultats en termes de conductivité ionique, sélectivité et stabilité.L'étude des principaux paramètres des membranes démontre une stabilité thermique entre 140 et 200 ° C selon la membrane sélectionnée, un comportement mécanique caractérisé par une résistance à la traction et un module d'élasticité élevée et un relativement faible ductilité, influencé par le niveau d’ hydratation de la membrane ou l éventuelle présence de cross-link. En optimisant le degré de fonctionnalisation et les types de groupes de fonctionnalisation, nous avons obtenu une accordable absorption d'eau, une conductivité ionique élevé pour différent ions (jusqu'à ≃ 3 mS / cm pour le polymère conducteurs des anions) et une perméabilité aux ions vanadium très faible (applications dans RFB) jusqu'à ≃ 10-10 cm2/min, ce qui est bien au-dessous des données typiques de la littérature et un paramètre très important pour applications technologiques. / The research aims to propose membranes for electrochemical devices alternative to the commercial ones able to reach the right compromise in term of good ionic conduction, stability and long life time for an high efficiency. We realized proton exchange, anion exchange and amphoteric membranes based on stable functionalized aromatic polymers (PEEK, PSU). We thus introduced sulfonic groups on a PEEK backbone to exchange protons or ammonium groups on PEEK and PSU to exchange anions. We also realized amphoteric membranes able to exchange at the same time both kinds of ions. The continuous optimization of synthesis parameters, the choice of different polymers and/or functionalization groups and the improvement of casting procedures and treatments of membranes, led to good results in terms of ionic conductivity, selectivity and stability.The study of the main parameters of the synthesized membranes demonstrates a thermal stability between 140 and 200°C depending on the selected membrane, a mechanical behavior characterized by a high elastic modulus and tensile strength and a relatively low ductility strongly influenced on the degree of hydration of the membrane as well as the eventual presence of cross-linking. Working on the degree of functionalization and the type of functionalizing groups, we obtained a tunable water uptake, an elevated ionic conductivity for different ions (up to ≃ 3 mS/cm for anionic conducting polymers) and a very low ion permeability (vanadium ions for RFB applications) down to ≃ 10-10 cm2/min, which is much below typical literature data for cation- and anion separation membranes and a challenge parameters for technological applications.

The evaluation of N′-(1-(2-pyridyl)ethylidene)nicotinohydrazide (HL) as a linker for the PbII tagged extended structures is described. The reaction of Pb(ClO4)2 or Pb(OAc)2 with HL in MeOH at 60 °C and room temperature, respectively, leads to heteroleptic complexes {[PbL]ClO4}n·nH2O and [PbL(OAc)]2, while the same reaction of Pb(ClO4)2 with HL at 60 °C in the presence of two equivalents of NaOAc or NaNO2 leads to heteroleptic complexes {[Pb(HL)(OAc)]ClO4}n and [PbL(NO2)]n, respectively. Using Pb(NO3)2 as a source of PbII in the same reaction with HL and two equivalents of NaN3 or NaNCS at room temperature yields [PbLN3]n and [Pb2(HL)2(NO3)2(NCS)2], respectively. The room temperature reaction of Pb(NO3)2 with HL in the presence of two equivalents of NaClO4 leads to the transformation of the parent ligand to its perchlorate salt [H2L]ClO4. In all the obtained PbII structures, HL or its deprotonated form L acts both as a chelating and a bridging ligand. The nature of the inorganic anion also influences the final structure. In all complexes the PbII center exhibits a hemidirected coordination geometry with all the covalent bonds being concentrated on one hemisphere of the coordination sphere with the closest approach of two atoms on the other side varying from 151° to 232°. The sterically available PbII ion participates in tetrel bonding as evidenced from the detailed structural analysis of the described complexes. As a result of tetrel bonding, the structures of all the six compounds can be extended to a higher dimensional framework, which is further stabilized by π⋯π stacking interactions between the aromatic rings. The DFT based charge and energy decomposition (ETS-NOCV) calculations are performed in order to shed light on the nature of non-covalent interactions that determine the stability of the obtained structures.

Les jonctions communicantes jouent un rôle important dans la prolifération et la réactivité vasculaire systémique. Dans cette étude, nous avons recherché le rôle de ces structures dans la paroi artérielle pulmonaire saine et dans l’hypertension artérielle pulmonaire (HTAP). L’HTAP est une pathologie de la circulation pulmonaire caractérisée par une prolifération cellulaire pathologique et une hyperréactivité à divers agonistes vasoconstricteurs tels que la sérotonine (5-HT). Dans la paroi artérielle pulmonaire de rats sains les protéines constituant les jonctions communicantes vasculaires (les connexines 37, 40 et 43) sont présentes. De plus, la connexine 43 située au niveau de la jonction myoendothéliale (JME) intervient dans la réactivité à la 5-HT. La 5-HT produit par ailleurs, (1) de l’anion superoxyde (O2?) au niveau du muscle lisse et (2) un vasodilatateur (le monoxyde d’azote (NO)) au niveau de l’endothélium. La JME va permettre le passage de l’O2? du muscle lisse vers l’endothélium de façon à piéger le NO et maintenir une contraction physiologique de l’artère pulmonaire. L’étude des jonctions communicantes dans la circulation pulmonaire pathologique a été réalisée sur deux modèles de rats atteints d’HTAP : (1) le modèle de rat atteint d’HTAP suite à une injection de monocrotaline (rat MCT) et (2) le modèle de rat atteint d’HTAP suite à une hypoxie chronique (rat HC). Les connexines 37, 40 et 43 sont également exprimées au niveau de la circulation pulmonaire de ces rats, mais leur distribution au niveau du muscle lisse et l’endothélium est modifiée. La réactivité des artères pulmonaires à divers agents vasoconstricteurs (5-HT, endothéline-1, phényléphrine, solutions dépolarisantes) est modifiée chez les rats MCT et HC. De plus, l’implication des jonctions communicantes dans la réactivité à ces agents est changée chez les rats MCT et HC. Ces données apportent de nouvelles connaissances sur le rôle des jonctions communicantes dans la réponse contractile des artères pulmonaires saines, et de nouveaux éléments permettant de mieux comprendre les altérations de la vasomotricité pulmonaire observée dans l’HTAP. / Gap junction communication plays an important role in proliferation and in the regulation of vascular reactivity. In this study, we investigated the role of gap junctions in physiological pulmonary circulation and in pulmonary arterial hypertension (PAH). PAH is the main pathology of pulmonary circulation and is characterized by cell proliferation and hyperreactivity to several contractile factors such as serotonin (5-HT). In pulmonary circulation from healthy rats, gap junction proteins were observed (connexins 37, 40 and 43). Moreover, connexin 43 located at the myoendothelial junction (MEJ) is involved in the reactivity to 5-HT in pulmonary arteries from healthy rats. Indeed, 5-HT produces (1) superoxyde anion (O2?) from smooth muscle and (2) a vasodilator (nitric oxide (NO)) from endothelium. O2? will pass through MEJ from the smooth muscle to the endothelium in order to scavenge NO and thus maintain contraction in physiological conditions. Gap junctions study in pathological pulmonary arteries has been performed on two animal models of PAH: (1) monocrotaline-induced PAH (MCT rat) and (2) chronic hypoxia-induced PAH (CH rat). Connexins 37, 40 and 43 were observed in pulmonary circulation from these rats, but the localization in smooth muscle and endothelium is modified. Moreover, pulmonary arterial vasoreactivity in response to several contractile agents (5-HT, endothelin-1, phenylephrine, depolarizing solutions) is modified in MCT and CH rats. Finally, the role of gap junctions in the reactivity to these agonists is changed in MCT and CH rats. These data have important implications for understanding physiological vasoreactivity to 5-HT in pulmonary circulation, and to better understand alterations of pulmonary arterial reactivity observed in PAH.