Submitted by MARCELO GALINDO LAHOUD null (marcelo_lahoud@hotmail.com) on 2016-08-29T14:30:25Z No. of bitstreams: 1 Tese.pdf: 5422221 bytes, checksum: 5ec64c3a1cf3ba55c1ca566db0e47a8b (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-08-30T17:19:13Z (GMT) No. of bitstreams: 1 lahoud_mg_dr_araiq.pdf: 5422221 bytes, checksum: 5ec64c3a1cf3ba55c1ca566db0e47a8b (MD5) / Made available in DSpace on 2016-08-30T17:19:13Z (GMT). No. of bitstreams: 1 lahoud_mg_dr_araiq.pdf: 5422221 bytes, checksum: 5ec64c3a1cf3ba55c1ca566db0e47a8b (MD5) Previous issue date: 2016-08-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho é dividido em duas partes, na primeira parte foi caracterizado o complexo [Ln(keto)3(H2O)] (Ln = Gd, Eu) por espectroscopia vibracional no infravermelho, analise elementar e otimização da geometria por método DFT. Mas o foco central foram os estudos das propriedades luminescente no intervalo de 12 – 300 K. O espectro de emissão do [Eu(keto)3(H2O)] revela uma forte dependência com a temperatura, bem ilustrada pelo não usual deslocamento amplo para o azul de (17 cm1) da transição 5D07F0 quando a temperatura é elevada de 12 a 300 K. A diferença aritmética entre os espectros de absorção do [Eu(keto)3(H2O)] com o do [Gd(keto)3(H2O)] indicou a presença de uma banda de transferência de carga do ligante para o metal (LMCT) (320-370 nm). A partir da fosforescência do [Gd(keto)3(H2O)] a energia dos estados de tripleto relacionada ao Keto foi determinada mostrando uma grande sobreposição com os níveis intra-4f6 e um forte acoplamento elétron-fônon. A alta ressonância entre o nível LMCT e estados tripletos e os níveis do Eu3+ leva a uma forte dependência do valor do tempo de vida da 5D0, típico da presença de processos de transferência de energia operativos. A segunda parte desse trabalho compreendeu na síntese, caracterização e estudos das propriedades luminescente e magnéticas de uma MOF inédito de formula [Eu2(Btec)1,5(H2O)]n. A MOF foi sintetizada por via hidrotermal e caracterizado por DRX de monocristal e pó, espectroscopia vibracional no infravermelho, reflectância difusa, analise elementar, analise térmica, microscopia eletrônica de varredura e fisissorção de N2. O composto apresentou boa estabilidade térmica no entanto mostrou-se ter baixa porosidade. A MOF apresentou emissão na região do vermelho com elevado rendimento quântico de emissão, mostrando que o ligante é um bom sensibilizador nesse sistema. As emissões dos íons Eu3+ mostraram-se ser uma sonda espectroscópica, contribuindo na elucidação da estrutura. Foi observado uma dependência térmica em relação à intensidade das transições originárias do nível 7F1, em especial a transição 7F15D1. Além disso, as transições intraconfiguracionais 4f-4f mostram ter uma boa fotoestabilidade. Resultados de susceptibilidade magnética mostram íons Eu3+ magneticamente afastados e portanto os torna uma fraca probe estrutural. / This work is divided into two parts, the first part was characterized the complex [Ln(keto)3(H2O)] (Ln = Gd, Eu) by infrared spectroscopy, elemental analysis and geometry optimization by DFT method. But the central focus was the study of luminescent properties in the 12-300 K interval. The emission spectra of [Eu(keto)3(H2O)] reveal a strong dependence with the temperature, well-illustrated by an unusual large blue-shift (17 cm1) of the 5D07F0 transition as the temperature is raised from 12 to 300 K. The arithmetic difference between the absorption spectrum of [Eu(keto)3(H2O)] with that of [Gd(keto)3(H2O)] pointed out the presence of a ligand-to-metal charge transfer (LMCT) band (320-370 nm). From the [Gd(keto)3(H2O)] phosphorescence the energy of the keto-related triplet states was determined showing a large overlap with the intra-4f 6 levels and a strong electron-phonon coupling. The high-resonance between the LMCT and triplet states and the Eu3+ levels leads to a strong dependence of the 5D0 lifetime value, typical of the presence of operative energy transfer processes. The second part of this work included in the synthesis, characterization and study of luminescence and magnetic properties of a novel MOF formula [Eu2(Btec)1,5(H2O)]n. The MOF was synthesized by way hydrothermal and characterized by XRD of single crystal and powder, infrared spectroscopy, diffuse reflectance, elemental analysis, thermal analysis, scanning electron microscopy and N2 physisorption. Compound demonstrated good thermal stability however proved to have low porosity. MOF showed emission in the red region with a high emission quantum yield, showing that the ligand is a good sensitizer in the system. The emission of Eu3+ ions proved to be a spectroscopic probe, contributing to the elucidation of the structure. A thermal dependence was observed in relation to the intensity of originating 7F1 level transitions, in particular the 7F15D1 transition. Furthermore, the 4f-4f transitions intraconfigurational shown to have a good photostability. Magnetic susceptibility results show Eu3+ ions separated magnetically and thus makes a weak probe structure.

Made available in DSpace on 2014-10-09T12:28:04Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:01:23Z (GMT). No. of bitstreams: 0 / Este trabalho apresenta as propriedades ópticas dos complexos Európio Tetraciclinas (EuTcs) na presença de LDL e de LDL oxidada com potenciais aplicações em análises clínicas. Foram escolhidos quatro elementos da família das Tetraciclinas: Tetraciclina (Tc), Clorotetraciclina (CTc), Metatetraciclina (MTc) e Oxitetraciclina (OTc) para fazerem parte dos complexos com o íon európio. As melhores condições para se formar os complexos eficientemente foram determinadas, através das medidas dos parâmetros ópticos como: absorção, emissão e de tempo de vida. As melhores concentrações de európio nos complexos EuTcs e possíveis influências de íons inorgânicos normalmente presentes no plasma sanguíneo também foram analisadas. As amostras foram preparadas em pH neutro e a luminescência visível do lantanídeo foi detectada após tempo de repouso das amostras de 15 minutos. Os resultados deste trabalho mostraram que as moléculas de LDL e de LDL oxidada apresentaram um importante papel no aumento da intensidade de emissão dos complexos das Tcs. As medidas realizadas com os complexos EuTcs não apresentaram deslocamentos nos comprimentos de onda dos espectros de absorção e de emissão na presença de LDL, o que demonstra a ausência de interação direta entre as moléculas de Tcs e as moléculas de LDL e LDL oxidada. No entanto, o íon európio pode interagir em diferentes sítios das moléculas de tetraciclinas o que diferenciou a intensidade de emissão de cada complexo. Comparando os resultados obtidos entre os complexos de EuTcs, o complexo EuTc foi o que apresentou perspectivas promissoras na quantificação de LDL e LDL oxidada. / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Made available in DSpace on 2014-10-09T12:28:07Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:01:37Z (GMT). No. of bitstreams: 0 / Neste trabalho foram estudadas as propriedades espectroscópicas do íon európio trivalente complexado à componentes da família das tetraciclinas, a clorotetraciclina, oxitetraciclina e metaciclina, em presença de peróxido de hidrogênio e peróxido de uréia. Para isso foram obtidos os parâmetros ópticos de absorção, emissão, tempo de vida e construídas curvas de calibração para os espectros de luminescência. Realizaram-se experimentos com compostos inorgânicos juntamente com os complexos a fim de verificar a interferência dos mesmos. Também foram realizados estudos para determinação de glicose utilizando os complexos európiotetraciclinas como biossensor. Os resultados mostram que os complexos európiotetraciclinas apresentam um espectro de emissão bem definido na região do visível e, na presença de peróxido de hidrogênio ou peróxido de uréia, há um aumento sensível na luminescência e tempo de decaimento. Assim, os complexos európiotetraciclinas estudados podem ser utilizados como biossensores para determinação dos peróxidos de hidrogênio e uréia, sendo um método realizado em temperatura ambiente, direto e de baixo custo. Um método indireto para determinação de glicose foi estudado através da adição da enzima glicose oxidase aos complexos európiotetraciclinas na presença de glicose no qual há como produto o peróxido de hidrogênio. / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

In many countries the current plan for the management of intermediate and high level radioactive wastes is to dispose of the radioactive materials underground in a Geological Disposal Facility (GDF) to prevent release of radioactivity to the environment. In the UK, the repository for intermediate level waste may be backfilled with cementitious material and it is clear that grout and cement will be used during many disposal concepts. Upon saturation, the cement will react creating a region of hyperalkaline geochemical conditions extending away from the GDF, within which, significant changes in radionuclide behaviour are expected. Therefore, this thesis utilises a range of experimental and analytical techniques to try to gain a mechanistic understanding of the behaviour of some key radionuclides (U(VI), Np(V) and Eu(III) as an analogue for Cm(III)/Am(III)) in a range of high pH systems of direct relevance to any cementitious GDF. U(VI) interaction with calcite (calcium carbonate, a common component in high pH cements and the natural environment) surfaces was studied in the 'old' (Ca(OH)2 solution; pH 10.5) and 'young' (Na+, K+, Ca2+; pH 13.3) leachates. In the 'old' leachate, luminescence spectroscopy, batch experiments and kinetic modelling suggested that at low concentrations (smaller or equal to 0.42 µM) a Ca2UO2(CO3)3-like surface complex formed. At higher concentrations, batch experiments, extended X-ray absorption fine structure spectroscopy and luminescence suggested that a surface mediated precipitation mechanism was controlling U(VI) concentrations. Further TEM analysis confirmed that a calcium uranate (CaUO4) solid phase was forming on the calcite surfaces. In the 'young' leachate, batch experiments showed that U(VI) had little affinity for the calcite surface, with no statistically relevant removal from solution observed over a 18 month period. Small angle X-ray diffraction data demonstrated that the U(VI) was probably present in the form of U(VI) intrinsic colloids. Np(V) solubility and sorption to calcite under hyperalkaline conditions were studied using batch, X-ray absorption spectroscopy, and geochemical modelling techniques. It was determined that Np(V) solubility in 'old' cement leachates was consistent with the literature. However, in 'young' cement leachates, an unidentified calcium containing phase was controlling solubility. It was demonstrated that sorption to calcite in 'old' leachates was controlled by the formation of a >CO3NpO2 surface complex, whereas, in the 'young' leachates interaction with the calcite surface was controlled by a precipitation mechanism. Eu(III) sorption to a potential GDF backfill material, Nirex Reference Vault Backfill (NRVB) cement, was studied. The kinetics of removal were rapid with 98.5% Eu(III) removal within 24 hours. Ultrafiltration experiments indicated that all Eu(III) remaining in solution was associated with NRVB derived colloids. Additional experiments using ethylenediaminetetraacetic acid (EDTA) as a competing ligand show that removal from solution was significantly reduced at high concentrations (>0.01 M). These EDTA experiments also indicated some irreversibility in the systems, possibly caused by incorporation into the C-S-H or calcite structures.

Les oxynitrures dopés terre rare présentent des propriétés intéressantes pour un usage en tant que luminophore pour LEDs blanches. Une nouvelle famille de luminophores dopés Eu2+ ou Ce3+ avec un réseau hôte oxynitrure de structure apatite a été étudiée : La8+xSr2-x(Si/Ge)6NyO26+x/2-3/2y. L’ammonolyse d’un précurseur oxyde de structure apatite a été utilisée comme technique générale de nitruration. Elle a permis de diminuer substantiellement la température de nitruration en comparaison avec la méthode classique par réaction à l’état solide sous atmosphère mixte N2/H2. Les différentes luminescences des luminophores obtenus ont été étudiées et corrélées à la structure cristalline à l’aide de différentes techniques de caractérisation.La structure apatite présente notamment la particularité de proposer plusieurs sites anioniques pour l’introduction de l’azote ainsi que deux sites cationiques pour les ions terre rare activateurs. L’utilisation de nombreuses techniques de caractérisation (IR, Raman, RMN, diffraction des neutrons) a permis d’obtenir des informations sur la position de l’azote. En parallèle, la comparaison des propriétés optiques avec celles de composés réduits sous Ar/H2 a permis d’attribuer les émissions aux différents sites cristallins disponibles dans la structure. Des mesures de rendement quantique ainsi que des tentatives d’optimisation des propriétés de luminescence ont été effectuées. / Rare-earth doped oxynitrides have attracted much attention as phosphors for white LEDs. A new family of Ce3+ or Eu2+-doped oxynitride phosphors with the apatite structure has been studied: La8+xSr2-x(Si/Ge)6NyO26+x/2-3/2y. The ammonolysis of an apatite oxide precursor has been used as a general method of synthesis, allowing decreasing the nitriding temperature respective to the classical solid state reaction in N2/H2 atmosphere. The luminescence properties of the obtained phosphors have been studied and relationships with the crystalline structure have been drawn.The apatite structure shows several crystallographic sites available for nitrogen as well as two cationic sites for optically active rare-earth ions. Several structural characterization technique have been used (IR, Raman, NMR, Neutron diffraction) and important information has been obtained concerning the nitrogen distribution in the available positions of the crystal structure. Comparison of the luminescent properties with those of compounds reduced under Ar/H2 allowed attributing emissions to the different crystallographic sites available in the structure.Quantum efficiency measurements have been carried out as well as trials for improving the intensity of the luminescent properties.

L’objectif de ce projet a été de concevoir des matériaux émissifs recyclables à base de lanthanide, en vue de remplacer les oxydes contenus dans les lampes fluoro-compactes (CFLs). Les lanthanides, en particulier l’Eu¹¹¹ et le Tb¹¹¹ ont été les principaux « ingrédients » dans les phosphores à cause de leurs émissions fines dans le rouge et le vert. Les complexes tris-dipicolinate de lanthanides, solubles dans l’eau sont connus pour leurs excellentes propriétés de luminescence, ce qui en fait de bons candidats pour des applications dans le domaine de l’éclairage.Cette thèse décrit l’étude des complexes de tris-dipicolinate d’Eu¹¹¹ et de Tb¹¹¹ sous forme cristalline avec différents contre-cations, ainsi que des systèmes plus complexes comme des co-cristaux ou des de cristaux cœur/coquille. Ces complexes ont également été utilisés comme dopant dans des silices mésostructurées en utilisant une méthode dites de « incipient wet impregnation » (IWI). Les propriétés photophysiques de ces matériaux ont été étudiées en détail et une forte exaltation des propriétés d’émission a été mise en évidence dans les silices. En particulier, l’influence des oscillateurs O-X a été montrée et la détermination du rendement quantique intrinsèque nous a procuré une meilleure compréhension de cette exaltation.La recyclabilité des complexes de lanthanide dans la silice a pu être réalisée avec des bons rendements. Des matériaux, émettant de la lumière blanche ont pu être obtenus en mélangeant des émetteurs rouge, vert et bleu. Le naphtalimide a été choisi comme émetteur bleu. Ainsi, le mélange des complexes d’Eu¹¹¹ et de Tb¹¹¹ et de naphtalimide au sein d’une silice mésoporeuse a conduit à la première génération de matériaux émettant de la lumière blanche et pouvant être facilement recyclés. / The objective of this project was to explore recyclable lanthanide based materials suitable for replacing the oxides from compact fluorescent lamps (CFLs). Lanthanides, particularly Eu¹¹¹ and Tb¹¹¹ have been the main “ingredients” in phosphors due to their colour purity and sharp emission in the red and green range of the visible spectrum. Lanthanide tris-dipicolinates are water soluble complexes, known for their excellent photophysical properties which makes them great candidates for lighting. The thesis describes the study of Eu¹¹¹ and Tb¹¹¹ tris-dipicolinate complexes in the crystalline form with different cations, as well as more complex systems like mixed co-crystals and core/shell crystals. The Eu¹¹¹ and Tb¹¹¹ complexes were also used as dopant in mesostructured silica materials via an incipient wetness impregnation method leading to homogeneous materials. The photophysical properties these different materials were thoroughly studied and a significant exaltation of the emission was evidenced in the silica. In particular, the influence of the O-X oscillators was explored and determination of the intrinsec quantum yield gave a clearer image on this exaltation. The recyclability of the lanthanide complexes from the material has been proven with high rates. Finally, white light emitting materials were obtained by mixing red, green and blue emitters. The naphthalimide moiety was chosen as blue emitter and white luminescence was successfully obtained in the solid state and for a silica material, representing a first generation of recyclable white light emitting materials based on lanthanide tris-dipicolinate complexes.

L’objectif de ce travail est d’étudier la dégradation d’un polyesteruréthane industriel (PURm) par radio-oxydation puis par lixiviation en solution aqueuse à pH basique, dans le but d’évaluer le pouvoir complexant des produits de dégradation hydrosolubles (PDH) avec les actinides. Afin d’atteindre ces objectifs, le PURm a été caractérisé puis radio-oxydé à température ambiante sous rayonnements gamma jusqu’à 10 MGy. Il a ensuite été lixivié à pH 13,3 à différentes températures. De nombreuses techniques analytiques ont été employées afin de caractériser les PDH obtenus. De l’europium(III), simulant les actinides(III), a été mis en solution avec les PDH et l’interaction Eu-PDH a été analysée par spectrofluorimétrie laser à résolution temporelle (SLRT). Quelle que soit la dose reçue par le PURm, l’acide adipique et le butane-1,4-diol sont les deux PDH majoritaires. Les données de lixiviation acquises à 40 et 60°C, sur le PURm radio-oxydé jusqu’à 1 MGy, corrèlent avec le modèle proposé par Yoon et al. (1997). Par contre, les données à température ambiante (22°C en moyenne) ne sont pas en accord avec ce modèle. Il semble néanmoins que le taux de dégradation maximal atteint par le polymère soit similaire quelle que soit la température employée dans cette étude. Les résultats obtenus permettent de conclure que le mécanisme prédominant lors de la lixiviation en milieu basique du PURm non irradié et radio-oxydé est l’hydrolyse des groupes esters des segments souples. La complexation de l’europium(III) par les PDH à pH basique a été mise en évidence. La détermination de la constante de complexation et l’identification des ligands, dans certaines conditions, ont été réalisées. / The first aim of this work is to study the degradation of an industrial polyesterurethane (PURm) by radio-oxidation and then by leaching in an alkaline aqueous solution. The second aim is to measure the complexing power of hydrosoluble degradation products (HDP) with actinides. To reach these goals, PURm was first characterized and then radio-oxidized at room temperature with gamma rays up to 10 MGy. Second, it was leached at pH 13.3 at different temperature values. Numerous analytical techniques were employed in order to characterize the HDP. Europium(III) was used as an analogue of actinides(III) and the behavior of HDP with europium(III) was analyzed by time-resolved luminescence spectroscopy (TRLS). Whatever the received dose by PURm, the two main HDP are adipic acid and butane-1,4-diol. The leaching data acquired at 40 and 60°C, on the 1 MGy radio-oxidized PURm, correlate with the model given by Yoon et al. (1997). On the contrary, the data at room temperature (22°C in average) are not in agreement with the model. Nevertheless, it seems that the plateau which was reached after a long period of leaching is the same whatever the temperature used in this study. The results allow to conclude that the predominant mechanism occurring during the leaching of unirradiated and radio-oxidized PURm in an alkaline medium is the hydrolysis of the soft segments ester groups. The complexation of europium(III) by HDP in alkaline medium was demonstrated. The measurement of the complexing power and the identification of ligands was achieved under certain conditions.

Die Mechanismen von Immobilisierungsprozessen radioaktiver Schwermetall-Ionen innerhalb von Biofilmen sind noch weitgehend unerforscht. Das liegt an der Komplexität der Biofilme, welche häufig diskrete geochemische Mikromilieus bilden, die sich vom umgebenden Milieu („Bulk Solution“) in Bezug auf dessen Biozönose (der mikrobiellen Diversität), den darin herrschenden geochemischen Bedingung (z.B. Red/Ox-Potential u./o. gelöster Sauerstoffmenge), aber auch in der Konzentration möglicher Komplexbildner (z.B. Metaboliten u./o. EPS-Komponenten) deutlich unterscheiden. Alle diese Faktoren können die Speziation der Radionuklide verändern und damit auch deren Transportverhalten. Für ein besseres Prozessverständnis zu den Wechselwirkungen von Radionukliden mit natürlichen, in Uran-kontaminierten Milieus lebende Mikroorganismen und den damit verbunden Stoffen wurde die Biozönose in Biofilmen und im Grubenwasser des ehem. WISMUT-Uranbergwerkes Königstein nach klassischen mikrobiologischen- und molekularbiologischen Methoden bestimmt. Aus einem Vergleich der Chemie im Biofilm mit der Chemie der umgebenden Lösung wird der Einfluss der Biofilme auf das Migrationsverhalten von Radionukliden in der Natur beurteilt. Die Identifizierung und Quantifizierung von Prokaryoten erfolgte u.a. mit der CARD FISH Methode. Die selektive Visualisierung der EPS-Komponenten in der Matrix der Biofilme wurde mit Hilfe der Konfokalen Laser Scanning Mikroskopie (CLSM) bewerkstelligt. Zur Untersuchung der Speziation von fluoreszierenden Schwermetall-Ionen wie U(VI) kam die zeitaufgelöste, laser-induzierte Fluoreszenzspektroskopie (TRLFS) zum Einsatz. Um diese Methode auch im mikroskopischen Bereich anwenden zu können, wurde sie weiter zum CLSM hin entwickelt: Da ein 80-MHz-MaiTai-Laser zur Verfügung stand, wurde durch im kHz-Bereich alternierendes Beugen des Anregungslaserstrahls von der Probe weg (und wieder zu ihr hin) mittels akusto-optischem Modulator (AOM) eine quasi-gepulste Laseranregung im kHz-Bereich erreicht. Durch Einbindung von Frequenzvervielfachern („Harmonixx“ von APE Berlin und „Inspire“ von Spectra-Physics) konnte so eine gepulste Anregung innerhalb eines breiten Wellenlängenbereiches (ca. 230-1090 nm) ermöglicht werden. Für die Auswertung des als äußerst schwach zu erwartenden Fluoreszenzsignales (entsprechend des mikroskopisch kleinen Anregungsraumes) wurde die Time-Correlated Single-Photon Counting Methode (TCSPC) – auch „zeitbezügliche Einzelphotonenzählungs-Methode“ – an das Laser-Anregungssystem angepasst. Die Fluoreszenzlebenszeitkurve des Fluoreszenzsignals von U(VI) Species, die sich an der Oberfläche von den Protozoen Euglena Mutabilis befanden, konnte z.B. auf diese Art mit Hilfe der TCSPC ermittelt werden.

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