Orientador: Fernando Alvarez / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-08-11T05:33:37Z (GMT). No. of bitstreams: 1 Basso_RodrigoLeonardodeOliveira_D.pdf: 34307948 bytes, checksum: fd2817ddc7e94a48942bf4136fdb0472 (MD5) Previous issue date: 2007 / Resumo: Este trabalho apresenta um estudo sobre os efeitos da incorporação de carbono e nitrogênio na formação de uma camada monofásica, compacta e homogênea, composta por carbonitretos do tipo e -Fe2-3(C,N), na superfície da liga metálica AISI H13. Também são apresentados estudos sobre os efeitos da incorporação desses elementos nas propriedades mecânicas, químicas e na microestrutura da superfície da liga metálica. A incorporação desses elementos na superfície do material foi feita utilizando-se o tratamento termoquímico de nitrocarburização por plasma pulsado em atmosferas contendo N2+ H2+ CH4 em diferentes proporções. Além da composição da atmosfera de tratamento, também foram variadas a temperatura e o tempo de tratamento. De maneira a complementar o estudo do comportamento da liga metálica frente ao tratamento termoquímico a plasma, também foram preparadas amostras com atmosferas oxidantes contendo CO2. A análise da composição química da superfície das amostras foi feita através de espectroscopia de fotoelétrons e mostra que a incorporação de nitrogênio sofre grande influência da quantidade de gás contendo carbono, presente no plasma. Porém a incorporação desses elementos não é diretamente proporcional à concentração do gás contendo esse elemento. Ao contrário do esperado, aumentando-se suficientemente a concentração desses elementos na atmosfera de tratamento, não acarreta em aumento na concentração dos mesmos no material. Por outro lado a análise através de difração de raios X revelou a formação de estruturas cristalinas consistentes com o diagrama de fases do sistema Fe-C-N. Para menores concentrações de compostos de carbono no plasma, a formação de nitretos e carbonitretos é predominante enquanto que maiores quantidades desse elemento levam ao surgimento da fase cementita e -Fe3 C, indesejável por possuir baixa resistência mecânica. As propriedades mecânicas da superfície foram estudadas através de medidas de nano e micro-dureza e seus resultados indicam que, como esperado, amostras com maior quantidade de nitrogênio incorporada possuim maior dureza da superfície. Esse comportamento é condizente com a microestrutura observada por microscopia eletrônica de varredura que mostra o entrelaçamento dos grãos da estrutura do aço e o preenchimento de seus contornos com carbonitretos de ferro que dificultam a movimentação dos planos cristalinos do cristal aumentando sua dureza. Foi verificado que as concentrações de carbono e de nitrogênio contido no material exercem grande influência sobre a reatividade da superfície das amostras frente a processos corrosivos em meios contendo íons cloreto. Esse comportamento foi verificado através de medidas de corrosão em solução aquosa de NaCl a 0,9 vol.%. Novamente os resultados apontam que maior concentração de nitrogênio é responsável por conferir a superfície maior proteção contra corrosão. Esses resultados são atribuídos a presença de uma mono-fase compacta formada pela fase e - Fe2-3 (C,N) na superfície das amostras. Resultados menos significativos foram obtidos quando a superfície continha uma mistura de fases contendo g -Fe4 N, e -Fe2-3 N, a -Fe e CrN / Abstract: This work presents a study on the effect of the incorporation of carbon and nitrogen on he formation of a singlephase homogeneous layer, composed by e -Fe2-3(C,N) carbonitrides, on the top surface of a AISI H13 tool steel. We also present studies on the effect of the incorporation of these elements (C and N) in the microstructure and in the mechanical and chemical properties of the surface of the metallic alloy. The incorporation of these elements in the surface of the material was made using the plasma nitrocarburizing termochemical treatment in atmospheres containing N2 + H2+CH4 in different ratios. Beyond the composition of the treatment atmosphere, the temperature and the time of treatment had been also varied. In way to complement the study of the behavior of the metallic alloy we had been also prepared samples with oxidating atmospheres containing CO2. The chemical composition analysis of the sample¿s surface was made through X-ray photo-electron spectroscopy and pointed that nitrogen incorporation suffers great influence from the amount of gas containing carbon, on the plasma atmosphere. However the incorporation of these elements is not directly proportional to the concentration of the gas containing this element. In con-trast, increasing enough the concentration of these elements in the treatment atmosphere, it does not cause increase in the concentration of the same element in the material¿s surface. On the other hand the X-ray diffraction analysis showed the formation of crystalline structures, consistent with the phase diagram of Fe-C-N system. For lesser carbon concentrations in the plasma, the formation of nitrides and carbides are predominant whereas bigger amounts of this element lead to the formarion of the cementite phase (q -Fe3 C , undesirable for possessing low resistance mechanics). The mechanical properties of the surface had been studied by means of nano and microhardness and its results indicate that, as expected, samples with bigger amount of incorporated nitrogen possesses bigger hardness in its surface. This behavior is in agreement with the observed microstructure observed by scanning electron microscopy that show the interlacement of the grains of the steel structure and the fulfilling of its boundaries with iron carbonitrides that make it difficult the movement of the crystalline plans of the lattice increasing its hardness. It was verified that the nitrogen and carbon concentrations in the material¿s surface, are of great influence on the reactivity of the surface regarding to corrosive processes in clorine solutions. This behavior was verified by measurements of corrosion in NaCl aqueous solution. Again the results pointed that bigger nitrogen concentration is responsible for protecting the surface against corrosion process. These results are attributed to the presence of a compact and homogeneous e -Fe2-3(C,N) surface layer on the surface of the samples. Less significant results had been gotten when the surface contained a mixture of phases containing g -F e4N, e -Fe2-3 N, a -Fe e CrN / Doutorado / Física da Matéria Condensada / Doutor em Ciências

Des complexes bio-inspirés de zinc(II) ont été ancrés à la surface des nanopores d’une silice mésoporeuse de type MCM-41 adopté la technique du pochoir moléculaire à motifs périodiques pour assurer l’isolation des sites en utilisant des ions TMA+ comme espaceur pour contrôler le greffage des fonctions triméthylsilyle. L’objectif étant de mimer le doigt de zinc de l’anhydrase carbonique, une enzyme qui catalyse la réaction réversible d’hydratation du dioxyde de carbone en bicarbonate. Des complexes aminés de métaux de transition ont été aussi ancrés par analogie au site métallique de l’anhydrase carbonique avec un contrôle du voisinage moléculaire comparable à celui des matériaux contenant les complexes à base de zinc. L’interaction du CO2 adsorbé avec les sites actifs de ces matériaux a été aussi étudiée. Les matériaux intermédiaires sont caractérisés à chaque étape par un panel de techniques, dont DRX, analyses élémentaires, adsorption-désorption d’N2, FT-IR, 29Si RMN, XPS et RPE qui confirment l’intégrité de la structure poreuse et la formation des complexes. / Bio-inspired diethylenetriamine zinc(II) complexes were anchored into the nanopores of hexagonal mesoporous MCM41-like silicas. A step-by-step approach called “Molecular Stencil Patterning” was adopted to perform an in situ synthesis in order to mimic the zinc finger of the carbonic anhydrase. In the presence of a surface-masking pattern of TMA+ ions, some silanol groups were capped using grafted trimethylsilyl functions. Transition metal complexes have also been anchored in analogy to the metallic site of carbonic anhydrase with a molecular vicinity control comparable to that of materials containing zinc complexes. The interaction of adsorbed CO2 with the active sites of these materials has also been studied. The materials were characterized with a panel of techniques including XRD, elemental analysis, N2-adsorption-desorption, FT-IR, 29Si NMR, XPS and EPR that confirm the integrity of the porous structure and the complexes formation.

Nous visons dans ce travail de thèse à développer une méthodologie de fonctionnalisation par chimie click des silices hybrides synthétisées par voie sol-gel. La réaction click de cycloaddition azoture-alcyne catalysée au cuivre (CuAAC) offre une tolérance exceptionnelle pour les fonctions organiques en plus de conversions très élevées. Dans cette optique, nous avons mis en œuvre en premier lieu des matériaux clickables à base d'organosilice pure (organosilice à mésoporosité périodique (PMO) et silsesquioxanes pontés (BS)) qui ont permis une conversion quasi-quantitative de greffage par CuAAC. Nous avons ensuite utilisé cette particularité pour contrôler les propriétés de surface des BS en modifiant leur caractère hydrophile/lipophile. Dans le second axe de travail, nous nous sommes intéressés à l'apport de la chimie click pour la préparation de nanoparticules mésoporeuses de silice multifonctionnelles, dites mécanisées, pour des systèmes à délivrance contrôlée de principes actifs. / The present work aims to develop a trustful methodology of functionalization for hybrid silica materials made by the sol-gel process using the copper-catalyzed alkyne-azide cycloaddition (CuAAC)Click reaction. This transformation can be highly useful in materials science thanks to its high conversions and the excellent functional group tolerance. In this prospect, we have synthesized fully clickable bridged silisesquioxanes and periodic mesoporous organosilica that show high extents of click grafting. CuAAC was then used for tailoring the surface of bridged silsesquioxane and fine-tuning the hydrophilic/lipophilic balance. Finally, the click reaction was used as an efficient way to obtain multiply functionalized mesoporous silica nanoparticles in order to make nanomachines for controlled delivery of cargo molecules.

An ionic liquid (IL) is a salt, which usually is in the liquid state at normal temperature and pressure. The properties of ILs can be adjusted for various processes and applications by choosing different combinations of ions. Similar to other salts, ILs contain only ions with positive (cations) and negative (anions) charges in equal proportions. However, to prevent solidification, ions in ionic liquids usually contain bulky organic chemical groups, which, apart from electrostatic interactions, promote other types of interactions between ions, such as: (i) van-der-Waals interactions; (ii) hydrogen bonding; (iii) - stacking, etc., depending on the particular chemical structure of the ions. All these interactions, in combination, may lead to formation of specific microstructures in ILs, which may vary with temperature caused by changing thermal rotational and translational energies of the ions. Ions in these microstructures may have preferential orientations relative to each other, maintain anisotropic properties similar to those in liquid crystals or, in some specific cases, may even separate into microscopically organised liquid phases. Therefore, the dynamics of ILs may also be dependent on their microstructure. In many practical applications ionic liquids are placed on surfaces or in confinements. Solid surfaces introduce extra forces, which may be specific to the charge of the ions or/and to functional groups in the ILs. The geometry and interactions of ions in confinements or/and pores of materials may also disrupt specific bulk microstructures of ILs. Both confinement effects and interactions of ions with surfaces are manifested in the translational dynamics of the ions. One of the most direct and informative methods to study translational dynamics of ILs is pulse-field-gradient nuclear magnetic resonance (PFG-NMR).In this thesis the results of PFG-NMR studies on a few classes of ILs are reported: (i) the historically “standard” (since Walden’s discovery in 1914) ionic liquid, the ethylammonium nitrate (EAN) and (ii) halogen-free orthoborate-based phosphonium, imidazolium and pyrrolidinium ILs with varied structure and lengths of alkyl chains in cations, and varied structures of orthoborate anions. These ILs were studied in bulk at different temperatures, and also in confinements, such as between parallel glass and Teflon plates and in mesoporous Vycor glass. It was found that diffusion coefficients of cations and anions in EAN, phosphonium and pyrrolidinium orthoborate ILs in bulk are different, but according to the standard Stocks-Einstein model, they correspond to diffusion of ions in homogeneous liquids. A change in the chemical structure of one of the ions results in a change in both the diffusion coefficient of the oppositely charged ion and the activation energy of diffusion for both ions in an IL. Similar effects were observed from the chemical shifts and diffusion coefficients measured by NMR for imidazolium orthoborate ILs dissolved in polyethylene glycol solutions, in which imidazolium cations strongly interact with PEG molecules, further affecting the diffusion of orthoborate anions via electrostatic interactions. A liquid-liquid phase separation was suggested for a few phosphonium and pyrrolidinium bis(mandelato)borate ILs, in which a divergence of diffusion coefficients and activation energies of diffusion for cations and anions was detected at temperatures below ca 50 °C. In addition, a free-volume theory was invoked to explain the dependences of density of ILs on the alkyl chain length in cations.It was also found that for a phosphonium bis(salicylato)borate IL confined in 4 nm mesoporous Vycor glass the diffusion coefficients of ions increase by a factor of 35! This phenomenon was explained by the dynamic heterogeneity of this IL in micropores and empty voids of the Vycor glass. For EAN IL in confinements between glass and Teflon plates, the diffusion of ethylammonium cations and nitrate anions is significantly anisotropic, i.e. slower in the direction of the normal to the plates and faster along the plates compared to diffusion of the ions in bulk. A plausible explanation of this PFG NMR data is that EAN forms layers near polar and non-polar solid surfaces. A similar phenomenon, to a lesser extent, was also observed for phosphonium cations of bis(mandelato)borate, bis(salicylato)borate and bis(oxalato)borate confined between glass plates. The results of these studies may have implications in modeling tribological performance, i.e., friction and wear reduction for contact pairs of different materials lubricated by various classes of ionic liquids. / För godkännande; 2016; 20160420 (andfil)

De nombreux revêtements sont actuellement disponibles pour les aciers emboutis à chaud et trempés pour le domaine de la construction automobile. Afin d’augmenter les performances des produits actuels en termes d’aptitude à la mise en forme à chaud, de résistance contre la corrosion et de compatibilité avec les procédés de fabrication ultérieurs, les constructeurs automobiles et les sidérurgistes ont développé de nombreux types de matériaux alternatifs. Peu de produits ont trouvé une place importante dans l’utilisation industrielle. L’objectif de ce travail est de procéder à une vue d’ensemble des performances des produits actuels, d’identifier de nouveaux concepts de revêtements et d’étudier leur compatibilité pour l’application de la mise en forme à chaud. Cette étude porte sur les revêtements d’alliages de Zn-Mn. De nombreux bains électrolytiques et paramètres électriques ont été étudiés afin de déterminer des conditions de déposition optimales pour obtenir des alliages Zn-Mn avec une forte teneur en Mn. Les propriétés cristallographiques, microstructurales et anticorrosives de couches obtenues sur des plaques d’acier de grandes dimensions ont été caractérisées avec de nombreuses techniques. La compatibilité des couches protectrices pour le traitement d’austénitisation a été évaluée après des traitements thermiques à différentes températures et durées de chauffe. Une attention particulière a été portée sur l’évolution de la composition et des phases d’interdiffusion formées, ainsi que sur l’apparition de mécanismes d’oxydation et d’évaporation à haute température. Enfin, l’aptitude à la mise en forme à chaud et notamment la susceptibilité à la fissuration par métaux liquides de ces nouveaux revêtements ont été évaluées par des essais d’emboutissage / Various coatings are currently available for press-hardened steels used for the automotive construction, mainly with the aim of providing good anticorrosive properties to the body components. In order to improve performance of the coated products in terms of hot formability, corrosion protection and suitability for subsequent manufacturing processes, steelmakers and car manufacturers investigated various alternative coating materials. Only a few solutions resulted in a serial production. The aim of this study is to proceed to a screening of the performance of current coating variants, to identify new concepts for alternative coating materials and assess their suitability for the hot stamping application. The present work is focused on the study of Zn-Mn alloy coatings. Various electroplating baths and electric parameters were studied in order to determine optimal deposition conditions for obtaining Zn-Mn alloys with high Mn contents. The deposits obtained on large-scale steel plates were characterized with regards to their crystallographic, microstructural and anticorrosive properties. The behavior of the coating materials during austenitizing treatment was studied after heat treatment to different temperatures and heating durations. A particular attention was given to the evolution of the composition, the interdiffusion phases formed as well as to the presence of oxidation and evaporation mechanisms at high temperature. At last, the forming properties of the alternative coating materials and their susceptibility for liquid metal embrittlement were assessed on the basis of direct hot stamping experiments

Emerging markets in electrochemical energy storage, such as stationary grid storage, coupled with future concerns over the availability of lithium, places sodium-ion battery (SIB) technologies at a unique position to enter the market as a commercially viable alternative. Current shortcomings in the performance of cathode materials in SIBs would necessarily need to be addressed if this technology is to compete with existing commercial lithium-ion battery counterparts. Prussian White (PW), a promising cathode material currently being produced by Altris AB in Uppsala, Sweden, has been shown in many regards to be a promising candidate as a cathode material. In efforts to improve the lifetime, thermal stability, and rate capability of the material, both zinc oxide (ZnO) and polyaniline (PANI) coatings were applied to the active material powder.  Scanning electron microscopy (SEM) images of the ZnO coated PW showed that the ZnO was concentrated to certain regions, resulting in a rough and compromised coating. Furthermore, the notable presence of iron 2p orbital peaks in XPS spectra for ZnO and PANI coated samples, together with the SEM images, suggests that no method resulted in a conformal coating. Crystallographic information obtained using a capillary X-ray diffractometer showed that the PANI coating process had caused the PW to transition from a monoclinic to a cubic structure. This phase transition, based on subsequent thermogravimetric analysis, is attributed to an increase in both interstitial and lattice water content.  A comparative analysis of particle size and morphology, before and after slurry homogenization, showed that the ball milling technique used resulted in a reduction in size. Moreover, the ball milling process affected the uncoated PW more than the ZnO coated PW.  Findings, based on galvanostatic cycling of both full and half cells, indicate that the ZnO coating method on average results in a 12 mAh g1 loss in discharge capacity. The PANI coated PW showed a drop in capacity of approximately half that of the uncoated reference samples. No significant differences were observed in capacity retention, coulombic efficiency, and thermal stability between ZnO coated and uncoated PW. The better rate capability of the uncoated PW is suggested to be a result of the smaller particle size. Explanations for the observed similarities in electrochemical performance include (i) the breaking up of particles and agglomerates during the ball milling process (exposing uncoated faces), and (ii) the compromised coating. / Framväxande marknader inom elektrokemisk energilagring, såsom stationär nätlagring, i kombination med framtida oro över tillgängligheten av litium, placerar natriumjonbatteriteknik (SIB) i en unik position för att komma in på marknaden som ett kommersiellt lönsamt alternativ. Nuvarande brister i prestanda av katodmaterial i SIB måste nödvändigtvis åtgärdas om denna teknik ska konkurrera med befintliga kommersiella litiumjonbatterier. Prussian White (PW), ett lovande katodmaterial som produceras av Altris AB i Uppsala, Sverige, har i många avseenden visat sig vara en lovande kandidat som katodmaterial. I försök att förbättra materialets livslängd, termiska stabilitet och cyklingshastighetsförmåga applicerades både zinkoxid (ZnO) och polyanilin (PANI) -beläggningar på PW.  Svepelektronmikroskopi (SEM) -bilder av den ZnO-belagda PW visade att ZnO koncentrerades till vissa regioner, vilket resulterade i en grov och komprimerad beläggning. Vidare antyder närvaron av järn 2p orbitaltoppar i XPS-spektra för ZnO- och PANI-belagda prover, tillsammans med SEM-bilderna, att ingen metod resulterade i en lyckad beläggning. Kristallografisk information erhållen med användning av en kapillär röntgendiffraktometer visade att PANI-beläggningsprocessen hade orsakat en fasomvandling från en monoklinisk till en kubisk struktur. Denna fasomvandling, baserad på efterföljande termogravimetrisk analys, tillskrivs en ökning av både interstitiellt och gittervatteninnehåll.  En jämförande analys av partikelstorlek och morfologi före och efter homogenisering visade att den använda kulkvarnstekniken resulterade i en minskning i storlek. Dessutom påverkade kulkvarnsprocessen den obelagda PW mer än den ZnO-belagda PW.  Resultat, baserade på galvanostatisk cykling av både hel- och halvceller, indikerar att ZnO-beläggningsmetoden i genomsnitt resulterar i en 12 mAh g-1-förlust i urladdningskapacitet. Den PANI-belagda PW uppvisade en minskning i kapacitet på ungefär hälften av de obelagda referensproverna. Inga signifikanta skillnader observerades i kapacitetsretention, coulombisk effektivitet och termisk stabilitet mellan ZnO-belagd och obelagd PW. Den bättre hastighetsförmågan hos obelagd PW föreslås vara ett resultat av den mindre partikelstorleken. Förklaringar för de observerade likheterna i elektrokemisk prestanda innefattar (i) uppbrytning av partiklar och agglomerat under kulfräsningsprocessen (exponering av obelagda ytor) och (ii) ofullständig beläggning.

No description available.

The work presented in this thesis deals with experimental and theoretical studies related to alumina thin films. Alumina, Al2O3, is a polymorphic material utilized in a variety of applications, e.g., in the form of thin films. However, controlling thin film growth of this material, in particular at low substrate temperatures, is not straightforward. The aim of this work is to increase the understanding of the basic mechanisms governing alumina growth and to investigate novel ways of synthesizing alumina coatings. The thesis can be divided into two main parts, where the first part deals with fundamental studies of mechanisms affecting alumina growth and the second part with more application-oriented studies of high power impulse magnetron sputter (HiPIMS) deposition of the material. In the first part, it was shown that the thermodynamically stable α phase, which normally is synthesized at substrate temperatures of around 1000 °C, can be grown using reactive sputtering at a substrate temperature of merely 500 °C by controlling the nucleation surface. This was done by predepositing a Cr2O3 nucleation layer. Moreover, it was found that an additional requirement for the formation of the α phase is that the depositions are carried out at low enough total pressure and high enough oxygen partial pressure. Based on these observations, it was concluded that energetic bombardment, plausibly originating from energetic oxygen, is necessary for the formation of α-alumina (in addition to the effect of the chromia nucleation layer). Moreover, the effects of residual water on the growth of crystalline films were investigated by varying the partial pressure of water in the ultra high vacuum (UHV) chamber. Films deposited onto chromia nucleation layers exhibited a columnar structure and consisted of crystalline α-alumina if deposited under UHV conditions. However, as water to a partial pressure of 1*10-5 Torr was introduced, the columnar α-alumina growth was disrupted. Instead, a microstructure consisting of small, equiaxed grains was formed, and the γ-alumina content was found to increase with increasing film thickness. To gain a better understanding of the atomistic processes occurring on the surface, density functional theory based computational studies of adsorption and diffusion of Al, O, AlO, and O2 on different α-alumina (0001) surfaces were also performed. The results give possible reasons for the difficulties in growing the α phase at low temperatures through the identification of several metastable adsorption sites and also show how adsorbed hydrogen might inhibit further growth of α-alumina crystallites. In addition, it was shown that the Al surface diffusion activation energies are unexpectedly low, suggesting that limited surface diffusivity is not the main obstacle for low-temperature α-alumina growth. Instead, it is suggested to be more important to find ways of reducing the amount of impurities, especially hydrogen, in the process and to facilitate α-alumina nucleation when designing new processes for low-temperature deposition of α-alumina. In the second part of the thesis, reactive HiPIMS deposition of alumina was studied. In HiPIMS, a high-density plasma is created by applying very high power to the sputtering magnetron at a low duty cycle. It was found, both from experiments and modeling, that the use of HiPIMS drastically influences the characteristics of the reactive sputtering process, causing reduced target poisoning and thereby reduced or eliminated hysteresis effects and relatively high deposition rates of stoichiometric alumina films. This is not only of importance for alumina growth, but for reactive sputter deposition in general, where hysteresis effects and loss of deposition rate pose a substantial problem. Moreover, it was found that the energetic and ionized deposition flux in the HiPIMS discharge can be used to lower the deposition temperature of α-alumina. Coatings predominantly consisting of the α phase were grown at temperatures as low as 650 °C directly onto cemented carbide substrates without the use of nucleation layers. Such coatings were also deposited onto cutting inserts and were tested in a steel turning application. The coatings were found to increase the crater wear resistance compared to a benchmark TiAlN coating, and the process consequently shows great potential for further development towards industrial applications.

L'objectif de cette thèse est la synthèse d'un matériau modèle de la dioxygénase à manganèse, une enzyme oxydant des cycles aromatiques type catéchol grâce au dioxygène. Pour ce faire, nous avons découpé notre stratégie trois étapes constituant les différents chapitres de ce manuscrit : - La synthèse et la caractérisation des complexes de manganèse(II) avec des ligands tridentates. - L'optimisation d'une synthèse de silice mésoporeuse par micro-onde. - La fonctionnalisation des matériaux et le greffage des complexes, ainsi que les tests catalytiques préliminaires.Les ligands utilisés sont des amines tertiaires avec un bras alcyne et deux coordinants type pyridine, imidazole ou carboxylate. Ces complexes ont été cristallisés et/ou caractérisés par IR, RPE, SQUID et voltampérométrie cyclique. La synthèse par micro-onde, basée sur des conditions de synthèse hydrothermale classiquenous a permis de réduire le temps de synthèse d'un jour à deux heures. La qualité de ces nouveaux matériaux a été vérifiée par IR, ATG, BET, et DRX sur poudre. Ces matériaux sont ensuite bifonctionnalisés en utilisant une méthode de pochoir moléculaire avec une fonction azoture pour le greffage du complexe via "click-chemistry" ainsi qu'une fonction pyridine ou triméthylsilyle pour créer un environnement coordinant ou non proche du métal.Ces complexes et matériaux sont actifs dans l'oxydation du catéchol. / The objective of this work is the synthesis of model material for manganese dioxygenase which is an enzyme that oxidizes catechol-like substrates with dioxygen. Our strategy comprises three main steps that form the different chapters of this thesis: - Synthesis and characterization of manganese(II) complexes with tridentate ligands. - Optimization of a microwave-assisted synthesis of a mesoporous silica. - Functionalization of these materials and complex grafting, as well as preliminary catalytic tests. The ligands used are tertiary amines containing an alkyne arm and two coordinating arms with functions such as pyridine, imidazole or carboxylate. The complexes were crystallized and/or characterized by IR, EPR, SQUID and cyclic voltamperometry. Microwave synthesis, based on the conditions of classical hydrothermal synthesis, allowed us to reduce the synthesis time from one day to two hours. The quality of these new materials was verified by IR, TGA, BET and powder XRD. These materials are then bi-functionalized using a molecular stencil patterning mehod with a an azide function for complex grafting via click chemistry and a function pyridine or trimethylsilyl to control the coordinating ability of the metal environment. These complexes and materials are active in catechol oxidation with O2.

Die Schriftenreihe „Werkstoffe und werkstofftechnische Anwendungen“ behandelt Themengebiete der Werkstoffwissenschaft und -technik, der Oberflächentechnik sowie deren industriellen Anwendungen. Es werden aktuelle Forschungsergebnisse aus den vier Professuren des Instituts für Werkstoffwissenschaft und Werkstofftechnik der TU Chemnitz vorgestellt: Professur Elektronenmikroskopie und Mikrostrukturanalytik, Professur Verbundwerkstoffe und Werkstoffverbunde, Professur Werkstoff- und Oberflächentechnik, Professur Werkstoffwissenschaft. Weiterhin sind in der Schriftenreihe die Tagungsbände des jährlich am Institut stattfindenden „Werkstofftechnischen Kolloquium“ enthalten. Die einzelnen Bände beschäftigen sich mit den Forschungsgebieten Galvanische Metallabscheidung, Anodisieren, Thermisches und Kaltgas-Spritzen, Löten, Verbundwerkstoffe, Werkstoffverbunde, Wärmebehandlung, CVD-Beschichtungen/PVD-Beschichtungen, Simulation in der Beschichtungstechnik, Organisches Beschichten (Pulverbeschichten, Lackieren, Sol-Gel-Verfahren), Elektrochemisches Strukturieren, Thermomechanische Behandlung und Mechanische Werkstoffeigenschaften. / The book series „Werkstoffe und werkstofftechnische Anwendungen“ outlines up-to-date topics of material science and engineering, surface engineering as well as resulting industrial applications. Mainly, recent research results of the departments Composite Materials and Surface Engineering/Functional Materials of the Institute of Material Science and Engineering of Chemnitz University of Technology are presented. In addition, the book series includes the proceedings of the annual in-house conference “Werkstofftechnisches Kolloquium”. The separate volumes concentrate on the following fields of scientific research: Galvanised Coating, Anodising, Thermal and Cold Spraying, Soldering and Brazing, Composite Materials, Composite Structures, Thermal and Thermomechanical Treatment, CVD and PVD Coating, Simulation of Coating Processes, Organic coating (Powder Coating, Varnishing, Sol-Gel Processes), Electrochemical Structuring and Mechanical Material Properties.