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No. of bitstreams: 1 lippyfariamarques.pdf: 22312576 bytes, checksum: 4211af206576435ad4b8e5af6c3c6abf (MD5) Previous issue date: 2014-03-27 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O presente trabalho aborda a síntese e caracterização de complexos de lantanídeos (III) contendo os ânions 2,5-tiofenodicarboxilato (2,5-tdc2-) e hidrocinamato (cin-) e o ligante nitrogenado 2,2’-bipiridina (bpy), com o intuito de investigar suas características químicas e estruturais e correlacioná-las com as propriedades fotoluminescentes. Duas séries de compostos obtidos com o ânion 2,5-tdc2- foram formuladas como: [Ln2(2,5-tdc)3(dmf)2(H2O)2]·2dmf·H2O (Ln = Dy (1), Tb (2), Eu (3), Gd (4), Er (5)), [Nd2(2,5-tdc)3(dmf)2(H2O)2]·dmf·H2O (7) e {[Ln2(2,5-tdc)3(dmso)2]·H2O}n ( Ln = Dy (8), Tb (9), Eu (10), Gd (11), Nd (12), Sm (13), Yb (14), Ho (15), Er (16), Tm (17), Pr (18)). Duas séries de compostos com o ligante cin- foram obtidas e formuladas como: [Ln(cin)3(H2O)3]·3Hcin (Ln = Dy (19), Tb (20), Eu (21), Er (22) e Gd (23)) e [Ln2(cin)6(bpy)2] ( Ln = Tb (24), Eu (25) e Gd (26)). Todos os compostos sintetizados foram caracterizados por análise elementar (CHN), análise térmica (TG/DTA), espectroscopia vibracional na região do infravermelho (IV), espectroscopia de reflectância difusa (RD) e difração de raios X (policristal e monocristal). O estudo de suas propriedades ópticas foi obtido a partir dos espectros de emissão e excitação e pela curva de decaimento luminescente. Com base nos dados espectrais foram determinados os parâmetros de intensidade experimentais (Ω2 e Ω4), coeficientes de emissão radiativa (Arad) e não – radiativa (Anrad) e a eficiência quântica de emissão (ɳ) do nível 5D0 do íon Eu(III). As estruturas cristalinas dos complexos (7), (8) e (9) foram determinadas através da técnica de difração de raios X por monocristal, demonstrando a formação de redes metalo – orgânicas de lantanídeos porosas (LnMOFs). A atribuição dos estados tripleto (T1) do ligante 2,5-tdc2- foi feita a partir dos espectros de emissão dos respectivos complexos de Gd(III) , mostrando a possibilidade de transferência de energia intramolecular nesses compostos. Todos os compostos contendo o ligante cin- (19)-(26) tiveram suas estruturas determinadas por difração de raios X por monocristal. Apesar da possibilidade de ocorrência do efeito antena nos compostos (19), (20) e (21), a presença de três moléculas de água diretamente coordenadas aos íons lantanídeos (III), promovem uma supressão da luminescência. Para o complexo [Eu2(cin)6(bpy)2] (25) foram obtidos os parâmetros de intensidades (Ω2, Ω4 e Ω6), taxas de decaimento radiativo (Arad) , não – radiativo (Anrad), transferência de energia (WET), retro – transferência de energia (WBT) e rendimento quântico. Esses dados se encontram em excelente acordo com dados experimentais com tal complexo possuindo uma eficiência quântica (ɳ) de 67%, sugerindo que esse sistema pode ser excelente para o desenvolvimento de dispositivos luminescentes. / The present work reports the synthesis and characterization of lanthanide (III) complexes containing 2,5-thiophenedicarboxylate (2,5-tdc2-) and hydrocinnamate (cin-) anions and nitrogen ligand 2,2’-bipyridine (bpy) in order to investigate its chemical and structural features and correlate with the photoluminescent properties. Two series of compounds obtained from the 2,5-thiophenedicarboxylate anion were formulated as: [Ln2(2,5-tdc)3(dmf)2(H2O)2]·2dmf·H2O (Ln = Dy (1), Tb (2), Eu (3), Gd (4), Er (5)), [Nd2(2,5-tdc)3(dmf)2(H2O)2]·dmf·H2O (7) and {[Ln2(2,5-tdc)3(dmso)2]·H2O}n ( Ln = Dy (8), Tb (9), Eu (10), Gd (11), Nd (12), Sm (13), Yb (14), Ho (15), Er (16), Tm (17), Pr (18)). Two series of compounds obtained from the cin- ligand were formulated as: [Ln(cin)3(H2O)3]·3Hcin (Ln = Dy (19), Tb (20), Eu (21), Er (22) e Gd (23)) e [Ln2(cin)6(bpy)2] ( Ln = Tb (24), Eu (25) e Gd (26)). All synthesized compounds were characterized by elemental analysis (CHN), thermal analysis (TG/DTA), vibrational spectroscopy in the infrared region (IR), reflectance diffuse spectroscopy (DR) and Xray diffraction (powder and single crystal). The study of their optical properties was obtained from the emission and excitation spectra and by the luminescent decay curve. Based on spectral data, the experimental intensity parameters (Ω2 and Ω4), radiative emission (Arad) and non-radiative (Anrad) coefficients and emission quantum efficiency (ɳ) of the 5D0 level the Eu(III) ion were determined. The crystal structures of complexes (7), (8) and (9) were determined using single crystal X-ray diffraction analysis, showing the formation of lanthanide (III) metal-organic porous frameworks (LnMOFs). The assignment of the triplet states (T1) of the 2,5-tdc2- ligand was taken from the emission spectra of the respective complexes of Gd(III), showing the possibility of intramolecular energy transfer in these compounds.All compounds containing the cin- ligand (19)-(26) had their structures determined by single crystal Xray diffraction analysis. Despite the possibility of the antenna effect of compounds (19), (20) and (21), the presence of three water molecules directly coordinated to lanthanide (III) ions, promotes the luminescence suppression. For [Eu2(cin)6(bpy)2] (25) complex, the intensity parameters (Ω2, Ω4 e Ω6), radiative decay (Arad), non-radiative (Anrad), energy transfer (WET), back energy transfer (WBT) rates and quantum efficiency were obtained. These data are in excellent agreement with experimental data with such complex having quantum efficiency (ɳ) of 67% suggesting that this system can be excellent for the development of luminescent devices.

La cavitation acoustique (formation, croissance et effondrement de bulles de gaz dans un liquide soumis aux ultrasons) est à l'origine de réactions chimiques (sonochimie) via la génération de conditions extrêmes lors de l'effondrement des bulles. Des températures de 103-104K et des pressions de l'ordre de 1000 atm sont atteintes au cœur des bulles [1]. Dans ces conditions, les liaisons chimiques des molécules volatiles présentes dans les bulles peuvent être rompues, formant, dans le cas de solutions aqueuses, des radicaux OH et H. Par ailleurs, l'effondrement violent des bulles de cavitation peut être accompagné par l'émission de lumière, sonoluminescence (SL), qui est le sujet d'étude de ce travail. Cette émission lumineuse est formée d'un continuum, de l'UV au proche IR, similaire à l'émission d'un corps noir, sur lequel peuvent se superposer des lignes d'émission atomiques ou moléculaires.On distingue deux types de SL: la SL mono-bulle (SBSL) et la SL multibulle (MBSL). En général, les spectres de MBSL se différencient de ceux de SBSL par la présence de lignes d'émission (d'atomes alcalins, de radicaux hydroxy… [2]), si bien que les mécanismes d'émission ainsi que la nature des conditions à l'intérieur des bulles lors de leur effondrement ont longtemps été considérés comme différents pour les systèmes mono- et multi-bulles. Un pont a été érigé entre les deux systèmes par le travail de Liang et al. [3] qui mit en évidence les conditions expérimentales permettant l'apparition de lignes dans le spectre de SBSL. Dans ce contexte, l'objectif de ce travail était de comparer les émissions de SBSL (27 kHz) et MBSL à haute et basse fréquences (20, 203, 607 kHz) pour différentes solutions aqueuses. Un sonoréacteur monobulle a été développé, dans lequel la température, la nature et la pression de gaz dissous ainsi que la pression acoustique sont contrôlés. Les électrolytes étudiés étaient : NaCl et les chlorures de lanthanides luminescents Ce3+, Tb3+, Eu3+ et Gd3+. Ces derniers peuvent être excités soit par absorption de photons dans l'UV soit par collisions avec des particules énergétiques [4].Dans la première partie de ce travail, les conditions à l'intérieur d'une monobulle lors de son effondrement ont été estimées via un fit du continuum par l'équation de Planck du corps noir. Les températures du corps noir obtenues sont de l'ordre de 104K, en accord avec des études précédentes. Elles sont indépendantes de la présence de NaCl et de la pression acoustique alors que l'intensité de SL y est très sensible. Les résultats obtenus remettent en question l'utilisation du modèle du corps noir en SL. Des lignes d'émission atomique et moléculaire se superposent parfois au continuum de SL : en MBSL, et en SBSL dans certaines conditions particulières (pression d'argon suffisante, faible pression acoustique) [3, 5]. Ce travail met en évidence la similarité entre la forme de l'émission de OH en SBSL et en MBSL à 20kHz, ce qui indique des conditions intrabulles très proches dans les conditions expérimentales étudiées [6]. En SBSL sous 70mbar d'Ar, l'intensité des lignes diminue lorsque la pression acoustique augmente, jusqu'à leur disparition dans le continuum. Cette évolution peut apparaître comme un lien entre SBSL et MBSL.Par ailleurs, cette étude confirme que la concentration en sodium à l'interface bulle-liquide, qui peut être enrichie par l'utilisation d'un contre-ion tensioactif, est le paramètre clé de l'observation de l'émission du sodium en SBSL, suggérant que l'excitation du sodium a lieu soit à l'interface de la bulle, soit en son cœur, après injection de gouttelettes. La seconde partie de cette étude concerne l'effet de la fréquence ultrasonore et de la puissance acoustique sur l'intensité de luminescence des ions lanthanides en MBSL. La luminescence des ions Tb3+, Ce3+ et Eu3+ est ainsi observée. La comparaison des rendements de SL et de photoluminescence indique qu'à l'exception de Ce3+, l'excitation par photons est min / The importance of acoustic cavitation, i.e., the formation, growth and collapse of gaseous cavities in liquid exposed to ultrasound, in sonochemistry is based on the generation of extreme conditions upon bubble collapse. Temperatures and pressures inside the collapsing bubble are approximated to reach 104 K and 1000 atm, respectively [suslick-1999]. Under such conditions chemical bonds of the solvent vapour or volatile solutes present in the bubble core are easily cleaved, which in the case of aqueous systems, leads to the formation of chemically reactive OH and H radicals. These primary radicals either recombine leading to chemiluminescence, or diffuse into solution, where they are liable to react with other species. Of particular importance in this work is the light emission that accompanies cavitation, termed sonoluminescence (SL). This emission is a broad continuum ranging from 200nm to 900 nm, resembling the emission of a blackbody, which can be superimposed with atomic or molecular emission lines comparable to bremsstrahlung. It is necessary to distinguish two forms of SL, single-bubble (SBSL) and multibubble (MBSL). In general, MBSL spectra differ from SBSL spectra in that they contain emission lines, e.g., from alkali atoms or hydroxyl radicals [matula-1995]. Consequently, it was, until recently considered that the mechanisms of light emission, and the nature of the bubble interior upon collapse were fundamentally different for the single and multibubble systems. Considering that MBSL is a cloud of single bubbles a bridging theory is desired.With this background the objective of the present work was to conduct a comparative spectroscopic analysis of SBSL, driven at 27 kHz, and MBSL generated from low and high ultrasonic frequencies (20, 203 and 607 kHz) of aqueous electrolyte solutions. Therefore a single bubble sonoreactor was developed, where the temperature, gas content and type, as well as the acoustic pressure could be controlled. The electrolytes of choice were: sodium chloride and chlorides of the luminescent lanthanide ions, Ce3+, Tb3+, Eu3+ and Gd3+, which can be excited by UV light absorption and collisions with energetic particles [kulmala-1995]. In the first part of this work the conditions upon bubble collapse were approximated by fitting the broad-band continuum of SBSL spectra of water with 70 mbar of argon and a 0.5 M NaCl solution with 70 mbar of argon using Planck's law of blackbody radiation. The obtained blackbody temperatures are in the range of 104 K, which is in good agreement with previous studies, but with the discrepancy of being independent of the presence of NaCl and the acoustic pressure, whereas the SL intensity increased by a factor of more than 10 upon increased acoustic pressure. The different trends followed by SL intensity and blackbody temperatures question the blackbody model. Another observation questioning the blackbody model is the appearance of atomic and molecular emission lines in MBSL and as recently observed also in SBSL [liang-2007, young-2001]. The present work proofed that the key factors for line emission in SBSL are small amounts of argon and low acoustic pressure. Moreover, the work revealed that the shape of the OH• radical emission is very similar to that in MBSL spectra, indicating the strong similarity of intrabubble conditions in MBSL and SBSL under certain experimental conditions [schneider-2011]. An increase of the acoustic pressure caused the continuum to overlap the lines until they become indistinguishable giving the usually in SBSL observed featureless continuum. This advance is a big step toward bridging the gap between SBSL and MBSL. Furthermore this study reveals that the concentration of the sodium ion at the interface of a single bubble can be enriched with a surface active counterion and the concentration is crucial for the observation of the sodium line in SBSL, suggesting that excitation of sodium either takes place at the interface of the

Ce mémoire est consacré à l'élaboration, au greffage chimique de macrocycles azotés sur des surfaces, le développement des procédés d'élaboration de surfaces sensibles aux ions, l'évaluation de leurs propriétés et la réalisation de prototypes de capteurs chimiques sensibles aux ions. Les macrocycles azotés sont des cyclames sensibles aux ions de métaux de transition et des terpyridines sensibles aux lanthanides. Un capteur sensible à l'ion Fer (III) est réalisé par fonctionnalisation d'un ISFET et de structures de nitrure de silicium/silicium au moyen du greffage de macrocycles azotés de type cyclames sur la surface du dispositif. Un agent de couplage poly(méthylhydrosiloxane) (PMHS) permet cette immobilisation avec une grande efficacité. L'immobilisation d'un dérivé du cyclame (naphtyl-cyclam) sur des surfaces d'or a permis la préparation de capteurs chimiques sensibles aux ions. Les molécules de cyclame ont été déposées sur des électrodes en or par des interactions fortes entre le groupe de naphtyle et la surface d'or. Le film obtenu a été caractérisé en termes de composition, morphologie et propriétés électriques. La conductivité protonique du film naphtyl-cyclam a été mise en évidence par la spectroscopie d'impédance électrochimique (EIS) et la voltampérométrie cyclique (CV). Nous avons montré que l'immobilisation de dérivé de phényl-terpyridine sur des surfaces d'or a permis la préparation des capteurs chimiques sensibles aux ions Gadolinium (III). Les molécules de terpyridine ont été auto-assemblées sur des électrodes en or par des interactions fortes (greffage chimique) avec groupement thiol terminal. Les propriétés électriques de ces interfaces films sensibles/électrolyte sont décrites et des modèles théoriques sont proposés d'après les résultats expérimentaux obtenus par la spectroscopie d'impédance électrochimique / This dissertation is devoted to the elaboration, the chemical grafting of aminated macrocycles on surfaces, the development of elaboration processes of surfaces sensitive to the ions, the evaluation of their properties and the fabrication of prototypes of chemical sensors sensitive to the ions. The aminated macrocycles are cyclames, sensitive to transition metal ions and terpyridines sensitive to lanthanides. A chemical sensor sensitive to iron (III) ion is fabricated by means of the functionalization of an ISFET and of silicon nitride/silicon structures through grafting of aminated macrocycles of the cyclam type on to the surface of the device. The coupling agent poly(methylhydrosiloxane) (PMHS) allows such an immobilization with a high efficiency. The immobilization of a derivative of cyclam (naphtyl-cyclam) on gold surfaces allowed the preparation of chemical sensors sensitive to the ions. The molecule of cyclam was deposited on gold electrodes by strong interactions between the naphtyl group and the gold surface. The film obtained was characterized in terms of composition, morphology and electrical properties. The proton conductivity of the N-MNC film was brought out, for the first time, by electrochemical impedance spectroscopy (EIS) and by cyclic voltammetry (CV). We showed that the immobilization of the phenyl-terpyridine derived on gold surfaces allowed the preparation of the chemical sensors sensitive to gadolinium (III) ions. The molecules of terpyridine were self-assembled on gold electrodes by strong interactions (chemical grafting) with a final thiol group. The electrical properties of these sensitive films/electrolyte are described and theoretical models are proposed from the experimental results obtained by the electrochemical impedance spectroscopy

Les lanthanides sont de plus en plus étudiés par la communauté scientifique et leur utilisation au sein de dispositifs grand public ne fait que croître. Ces éléments sont en effet connus pour présenter des propriétés magnétiques et de luminescence remarquables. Ils sont alors particulièrement efficaces pour la création de molécules aimants ou de matériaux luminophores. Dans ces travaux de thèse, la synthèse, la cristallogenèse et les caractérisations magnétiques et photo-physiques de nouveaux complexes associant lanthanides et molécules organiques photo-actives sont étudiées. Ces dernières possèdent une conformation « trans » et « cis » et il est possible, grâce à un stimulus lumineux (irradiation UV), de passer de l'une à l'autre. Cette photo-isomérisation induit un changement des propriétés du complexe au sein duquel elles sont présentes. Dans la première partie, quatre nouveaux complexes à base de DyIII, EuIII, TbIII et SmIII sont présentés. Ils sont obtenus grâce à l'association de précurseurs de terres rares et d'une molécule organique dérivée de stilbène : la 4-styrylpyridine. Une forte modulation des propriétés optiques de ces composés induite par l'isomérisation du ligand est observée. Il est mis en évidence que celle-ci a un impact notable sur les propriétés de luminescence des composés et sur leur couleur émise. Dans un second temps, l'influence de cette isomérisation sur les propriétés magnétiques du complexe à base de DyIII est étudiée. La deuxième partie consiste en l'élargissement de l'étude à des molécules photo-actives voisines dans le but de caractériser l'influence du changement de certains groupements chimiques sur les propriétés de photo-isomérisation. Un dérivé de 4-styrylpyridine comportant un groupement diméthyle-amino a ainsi été associé avec un ion DyIII. Un nouveau complexe a été obtenu et ses propriétés magnétiques à l'état solide et en solution étudiées. Parallèlement, l'utilisation d'une nouvelle molécule comportant un groupement diéthyle-amino ainsi qu'une partie azobenzène a donné lieu à l'obtention de deux nouveaux composés à base de DyIII et de TbIII. L'impact de l'isomérisation de ce ligand sur les propriétés luminescentes du complexe à base de TbIII et sur les propriétés magnétiques du complexe à base de DyIII a ensuite été étudié. Dans une troisième partie, les perspectives d'évolution du sujet sont présentées. Une première stratégie consiste à utiliser des solvants moins protonant que le chloroforme afin d'observer une photo-isomérisation plus robuste. Une deuxième stratégie est d'utiliser un ligand magnétique photocommutable. Un radical de la famille des nitronyl nitroxide substitué par un groupement stilbène a ainsi été synthétisé et coordiné à des ions DyIII et TbIII. Leur étude photophysique est commentée. / Lanthanides are more and more studied by the scientific community and their use in devices and operating materials is exploding. These elements are indeed known to exhibit remarkable magnetic and luminescent properties. They are indeed particularly effective for the creation of singles molecule magnets or light emissive materials. In this thesis work, the synthesis, the crystal growth and the magnetic and photo-physical characterizations of new complexes that associates lanthanides and photo-active organic molecules are studied. The latter possess a " trans " and "cis" conformation and it is possible, thanks to a bright UV irradiation stimulus, to switch from one to the other one. This photo-isomerization leads to a modification of the properties of the complex in which they are part of. In the first part, four new complexes with DyIII, EuIII, TbIII and SmIII are presented. They are obtained thanks to the association of precursors of lanthanides and an organic molecule from the stilbene family: the 4-styrylpyridine. A strong modulation of the optical properties of these compounds led by the isomerization of the ligand is observed. It is highlighted that this one has a notable impact on the luminescent properties of these four compounds and on their color emission. Then, the influence of this isomerization on the magnetic properties of the complex with DyIII is studied. The second part consists of the extension of the study in lookalike photo-active molecules. The aim of this work is to characterize the influence of the change of a given chemical group on the photo-isomerization properties. A ligand that is closely related to 4-styrylpyridine containing a dimethyl-amino group, is associated with a DyIII ion. A new complex is obtained and its magnetic properties in the solid state and in solution are studied. Besides, the use of a new molecule containing a diethyl-amino group as well as an azobenzene part gave rise to two new compounds with DyIII and with TbIII. The impact of the isomerization of this ligand on the luminescent properties of the complex with TbIII and on the magnetic properties of the complex with DyIII is then studied. In the third part, the perspectives of evolution of the subject are presented. A first strategy consists is to use less protonatings solvents than the chloroform to observe a stronger photo-isomerization. The second strategy is to use a photo-switching magnetic ligand. A radical of the nitronyl nitroxide family substituted by a stilbene group was synthesized and coordinated to DyIII and TbIII ions. Their photophysical study is commented.

Computational chemistry lies at the intersection of chemistry, physics, mathematics, and computer science, and can be used to explain the behavior of atoms and molecules, as well as to augment experiment. In this work, computational chemistry methods are used to predict structural and energetic properties of small molecules, i.e. molecules with less than 60 atoms. Different aspects of computational chemistry are examined in this work. The importance of examining the converged orbitals obtained in an electronic structure calculation is explained. The ability to more completely describe the orbital space through the extrapolation of energies obtained at increasing quality of basis set is investigated with the use of the Sapporo-nZP-2012 family of basis set. The correlation consistent Composite Approach (ccCA) is utilized to compute the enthalpies of formation of a set of molecules and the accuracy is compared with the target method, CCSD(T,FC1)/aug-cc-pCV∞Z-DK. Both methodologies are able to produce computed enthalpies of formation that are typically within 1 kcal mol-1 of reliable experiment. This demonstrates that ccCA can be used instead of much more computationally intensive methods (in terms of memory, processors, and time required for a calculation) with the expectation of similar accuracy yet at a reduced computational cost. The enthalpies of formation for systems containing s-block elements have been computed using the multireference variant of ccCA (MR-ccCA), which is designed specifically for systems that require an explicit treatment of nondynamical correlation. Density functional theory (DFT) has been used for the prediction of the structural properties of a set of lanthanide trihalide molecules as well as the reaction energetics for the rearrangement of diphosphine ligands around a triosmium cluster.

Rare earth elements (REEs) are critical materials in many electronics and green technology products. Though the demand for REEs is growing rapidly, China controls over 90% of the REEs supply and the US currently is not producing any REEs. As most of the REEs occurred together in the mineral ores with low concentrations and they have similar chemical and physical properties, the extraction and purification processes are challenging. Conventional methods for producing REEs require large amounts of toxic chemicals and generate large amounts of hazardous wastes. Therefore, it is important to develop alternative REE sources as well as efficient and environmentally friendly processes to produce REEs domestically. In this dissertation, coal fly ash, a major coal combustion byproduct, was explored as a potential source for REEs. Novel separation and purification methods were developed for producing high purity REEs from class F coal fly ash.<div><br></div><div>First, a sequential separation process was developed to recover and concentrate REEs from class F coal fly ash. The ash was first digested using a NaOH solution and subsequently dissolved in an acid to extract REEs as well as other chemicals. About 74% of REEs, 92 % of SiO2, 74% of Al2O3, 24% of Fe2O3, and 65% of CaO were extracted. Most (>99%) of the extracted REEs and cations (Al+3, Fe+3, Ca+2) were captured in a cation exchange column. Negatively charged Si species were eluted by water. The captured REEs were separated from the other cations in the column. A solution of NaCl was used to elute the cations and most of the REEs, which were strongly adsorbed in the column, were eluted using a solution of diethylenetriaminepentaacetic acid (DTPA). In this separation process, high purity SiO2 (>99%), Al(OH)3 (>99%), and Fe(OH)3 (>95%) were produced. The eluted DTPA-REEs solution was then loaded in a cation exchange column. The REEs accumulated in the column could be further separated into pure REE fractions using a ligand-assisted displacement chromatography method (LAD), instead of the conventional liquid-liquid extraction method.<br></div><div><br></div><div>Detailed rate model simulations were developed for LAD and verified with experimental and literature data. The dynamic column profiles in simulations showed that a prestaurant which has a higher ligand affinity and a lower sorbent affinity than REEs is required to develop an isotachic train in LAD. When a constant-pattern isotachic train is developed, high concentration bands with high purity and high yield can be achieved. Further increase in column length is not needed. Thus, if purity, yield, sorbent, and ligand are fixed, the constant-pattern state gives the highest sorbent productivity and the highest ligand efficiency. It is critical to develop a method to find the general conditions required for developing constant-pattern states. Key dimensionless parameters affecting the constant-pattern states were formulated first based on the h-transformation theory for an ideal system and the shock layer theory for a nonideal system. Strategetic combinations of the key dimensionless groups were developed to express a dimensionless mininum column length as a function of the combined dimensionless groups. Rate model simulations were used to find various minimum column lengths for developing constant-pattern states from transient states. The simulation results were used to generate a correlation curve in a two-dimensional plot or map where the curve divided the map into two regions, the transient region, and the constant-pattern region. The map can be used to find the minimum required conditions for developing a constant-pattern state for a general LAD system at any scale.<br></div><div><br></div><div>A constant-pattern design method for both ideal and non-ideal (with significant mass transfer effects) LAD systems was developed based on the general correlation equation for the map. In addition, an equation for the yield of a target component as a function of the key dimensionless groups was derived based on the constant-pattern mass transfer zone lengths. The column length and operating velocity solved from the two equations ensured the yields and the constant–pattern state for the target components. A selectivity weighted composition factor was developed to allow the design method to specify a minimum target yield for one or multiple components. The design method is robust and scalable because it provides the optimal operating conditions to meet the minimum target yield and purity of one or multiple components for LAD systems at any scale. The design method was verified using simulations and experiments for different target yields, ligand concentrations, and feed compositions for ternary mixtures. The minimum target yields were achieved or exceeded in all cases tested. The results showed that high ligand concentration, long column length, and high effective sorbent selectivity can increase sorbent productivity. The minimum column length required to achieve a constant-pattern state and the productivity of LAD are limited by the lowest selectivity or by a minority component with a low concentration in the feed, even when it does not have the lowest selectivity. If both minor and major REE components in a mixture need to be recovered in the same LAD process, the overall productivity could be significantly limited. Thus, separating major components first and recycling/separating the minor components in a separate LAD process could increase the total productivity significantly. The productivities achieved using this design method are two orders of magnitude higher than the literature results with similar REE yields and purities.<br></div>

Recently much attention is given to lanthanides and their complexes as excellent catalysts for cleavage of nucleic acids. The thesis has been focused on the cleavage of plasmid and bacterial DNA by ions Nd3+ and Y3+ and by different carriers containing the lanthanide compounds. The creation of single-stranded nicks and double-stranded ones in the plasmid DNA molecules was studied by agarose gel electrophoresis. Verification of the cleavage of bacterial DNA was made by polymerase chain reaction using primers specific for the domain Bacteria and genus and species-specific primers. The results will be used in the development of the method that will allow perfect carriers`s coverage verification with the magnetic perovskit nucleus and other carriers with the lanthanide compounds.

Im Rahmen dieser Arbeit wurden die Komplexierungsreaktionen von dreiwertigen Lanthaniden (Ln) und Actiniden (An) mit (α-hydroxy-)carboxylathaltigen Betonzuschlagmitteln in An- und Abwesenheit von Calciumsilikathydrat-Phasen untersucht. Die erzielten Ergebnisse erlauben eine umfassende Beschreibung der Wechselwirkungen auf thermodynamischer und molekularstruktureller Ebene.

Imaging techniques have been developed for decades for the detection of biomolecules in biomedicine cells, in vitro or in living cells and organisms. The application however, often constrained by the available probes, whose optical properties may limit the imaging possibilities. It is very essential to improve the sensitivity of these devices by enhancing efficiency to detection. Recently, Fe3O4 has been used primarily in cancer theranostic application such as magnetic resonance imaging (MRI). However, its toxicity towards normal cells has been pointed out by scientific communities, when they are involved in in vitro (helics) cancer treatment. In this work, we have chosen to use α-Fe2O3, because it has proven to be less toxic than Fe3O4. Hematite is antiferromagnetic (AFM) at room temperature with a small canted moment lying within the crystal symmetry plane. At low temperature, hematite undergoes a magnetic phase transition from weak ferromagnetic (WFM) to a pure antiferromagnetic configuration (AF), which is known as the Morin transition. This magnetic property makes it possible for hematite to be applied in imaging technique. To enhance the optical properties, the α-Fe2O3 is doped with lanthanide ions due to their unique optical properties. Incorporation of these rare earth ions, enable the α-Fe2O3 to have enhance luminescence properties. Imaging techniques have been developed for decades for the detection of biomolecules in biomedicine cells, in vitro or in living cells and organisms. The application however, often constrained by the available probes, whose optical properties may limit the imaging possibilities. It is very essential to improve the sensitivity of these devices by enhancing efficiency to detection. Recently, Fe3O4 has been used primarily in cancer theranostic application such as magnetic resonance imaging (MRI). However, its toxicity towards normal cells has been pointed out by scientific communities, when they are involved in in vitro (helics) cancer treatment. In this work, we have chosen to use α-Fe2O3, because it has proven to be less toxic than Fe3O4. Hematite is antiferromagnetic (AFM) at room temperature with a small canted moment lying within the crystal symmetry plane. At low temperature, hematite undergoes a magnetic phase transition from weak ferromagnetic (WFM) to a pure antiferromagnetic configuration (AF), which is known as the Morin transition. This magnetic property makes it possible for hematite to be applied in imaging technique. To enhance the optical properties, the α-Fe2O3 is doped with lanthanide ions due to their unique optical properties. Incorporation of these rare earth ions, enable the α-Fe2O3 to have enhance luminescence properties. These lanthanide-doped nanoparticles (UCNPs) undergoes up-conversion process which have remarkable ability to combine two or more low energy photons to generate a singly high energy photon by an anti-stokes process and hold great promise for bio-imaging. These nanoparticles exhibit excellent photostability, continuous emission capability and sharp multi-peak line emission. With near infrared excitation, light scattering by biological tissues is substantially reduced. α-Fe2O3 have been singly and co-doped with Holmium, Thulium, and Ytterbium by both sol-gel and microwave methods. The doping of these lanthanides have shown improved luminescent properties of α-Fe2O3. The up-conversion has been observed from co-doping Thulium and Ytterbium. This work is a proof of concept to show the up-conversion in α-Fe2O3. However, the up-conversion intensity is low about 200000 CPS maximum observed, this could be due to the nature of the host structure quenching the luminescence. There is rather, a need to increase the intensity for the maximum application to be achieved. / Physics

Les protéines modifiées ont suscité un grand intérêt en raison de leur taille extrêmement petite par rapport à l'anticorps entier. Ces petites protéines de liaison ont démontré de nombreux avantages tels qu'une bio distribution rapide, une bonne pénétration dans le tissu tumoral et une élimination rapide du sérum et des tissus non-infectés. Ainsi, ces protéines devraient être d'excellentes alternatives aux anticorps pour les applications cliniques. Cette thèse présente le développement de biocapteurs basés sur des anticorps synthétiques et le transfert d'énergie par résonance de type Förster (FRET) résolu en temps par la détection de biomarqueurs. Les tests immunologiques à base de FRET sont établis en utilisant des complexes de terbium (Tb) comme donneurs de FRET et des boîtes quantiques semi-conducteurs (QDs) comme accepteurs de FRET. Les propriétés photophysiques exceptionnelles de ce couple de FRET Tb-QD permettent une détection quantitative ultrasensible. Des anticorps monocaténaires (single-domain antibody, sdAb) et des petites protéines d’affinité synthétiques (albumin-binding domain-derived affinity protein, ADAPT) sont utilisés pour étudier différentes stratégies de conjugaison d'anticorps, et quantifier des biomarqueurs cliniques (EGFR, HER2). Ce travail peut être considéré comme une condition préalable à l’utilisation des QDs en diagnostic clinique. / Engineered affinity proteins have raised great interest due to their extremely small size compared to full length antibodies. Such small binding proteins have demonstrated many advantages such as quick biodistribution, good penetration into tumor tissue, and fast elimination from serum and nondiseased tissues. Thus, they are expected to be excellent alternatives to antibodies for clinical applications. This thesis focuses on the development of biosensors based on engineered antibodies and time-resolved Förster resonance energy transfer (FRET) through biological recognition of biomarkers. FRET-based immunoassays are established using terbium complexes (Tb) as FRET donors and semiconductor quantum dots (QDs) as FRET acceptors. The exceptional photophysical properties of the Tb-QD FRET pair allow for ultrasensitive quantitative biosensing. Single-domain antibodies (sdAb) and small engineered scaffold antibodies (ADAPT) are used to investigate different antibody-conjugation strategies for quantifying human epidermal growth factor receptors (EGFR, HER2) as clinical biomarkers. This work can be considered as a prerequisite to implementing QDs into applied clinical diagnostics.