Teses / dissertações sobre o tema "Ion multivalent"

This dissertation focuses on the synthesis and electrochemical testing of new electrolyte salts for rechargeable multivalent ion batteries. In chapters 2 and 3 the synthesis of Mg and Ca hexafluoropnictogenate salts as well as the electrochemical behaviour of Mg(PF6)2 is presented. Pure samples of Mg(EF6)2 (E = P, As, and Sb) can be synthesized using Mg metal and NOPF6/NOSbF6 in CH3CN or via a ammonium salt deprotonation route using Me3NHAsF6 and Bu2Mg. The NOPF6 method was extended to the Ca variant, but isolation of a pure Ca(PF6)2 material required the presence of a crown ether. Electrochemical and microscopy measurements of THF-CH3CN solutions of Mg(PF6)2 show that the electrolyte good electrochemical stability and can facilitate the plating/stripping of Mg. Further, this electrolyte system can be cycled in a full cell using the Chevrel phase Mo6S8 cathode. The electrochemical stability of the AsF6− and SbF6− salts is lower than that of the PF6− salt and electrolyte decomposition is observed when cycling on Mg electrodes. In chapter 4 the development of a series of Mg aluminates [Mg(AlOR4)2] using a general synthetic platform based on Mg(AlH4)2 and various alcohols is presented. Preliminary electrochemical studies performed on these aluminate salts in dimethoxyethane identify the phenoxy and perfluoro-tert-butoxy derivatives as promising electrolyte systems. Electrochemical cycling of these electrolytes using gold and Mg electrodes show that systems containing chloride, brought through to the product from the starting material in the form of NaCl, exhibit lower plating/stripping overpotentials and higher Coulombic efficiencies than systems from which chloride had been removed. Further, these two electrolytes can be used in Mg full cells containing the Chevrel phase cathode. Solid-state 23Na NMR analysis as well as DFT calculations show that chloride-containing electrolytes facilitate the co-insertion of Na into the cathode material. In chapter 5 the hydroboration of pyridines and CO2 in the presence of pinacolborane is presented. An optimized system employing NH4BPh4 and HBpin is developed and a mechanism of pyridine hydroboration is proposed based on multinuclear NMR spectroscopy. The catalytic reaction was found to be catalyzed by a boronium salt, which was structurally characterized in the solid-state by single crystal X-ray diffraction. This new catalytic method is shown to be tolerant to a number of functional groups in the 3-position on pyridine as well as quinoline, and CO2, producing the hydroboration products in good yields.

Le premier chapitre introduit le concept et les caractéristiques fondamentales des matériaux moléculaires. Il met en évidence leurs vastes applications et les avantages qu'ils offrent dans les dispositifs électrochimiques, ainsi qu'un aperçu de leur développement dans ce domaine. Ensuite, les matériaux moléculaires sont classés de trois manières distinctes selon différents critères. Les sous-catégories de chaque classification sont systématiquement expliquées, mettant en lumière différents aspects des matériaux moléculaires selon la méthode de classification.À partir des batteries à ions multivalents, le deuxième chapitre introduit la batterie à ions aluminium émergente comme un système de stockage avec un grand potentiel. Les avantages du développement des batteries à ions aluminium sont montrés à partir des avantages objectifs de l'abondance naturelle et du prix de l'aluminium lui-même, ainsi que du potentiel électrochimique théorique de l'aluminium. Ensuite, du point de vue des électrolytes et des matériaux d'électrode, les batteries à ions aluminium et leur état de développement sont résumés à travers une classification détaillée et des exemples.Par conséquent, sur la base de notre compréhension des matériaux moléculaires et des batteries à ions aluminium, nous avons mené les deux projets suivants :Dans un travail de pionnier, nous avons rapporté les capacités de stockage d'ions lithium du polymère de coordination unidimensionnel (1D) bimétallique fer-nickel, {[FeIII(Tp)(CN)3]2[NiII(H2O)2]}n. Le résultat a d'abord confirmé l'intercalation réversible de Li+ dans le matériau moléculaire à pont cyanure 1D. Cette tentative réussie dans les batteries à ions lithium a éveillé notre intérêt pour explorer davantage la possible insertion d'ions aluminium dans une telle chaîne à pont cyanure unidimensionnelle. Dans ce travail, nous avons sélectionné l'électrolyte liquide ionique ([EMIm]Cl-AlCl3 avec un rapport de 1,1:1 (AlCl3 : ([EMIm]Cl)) comme électrolyte, et développé une série de matériaux unidimensionnels (1D) avec la formule {[FeIII(Tp)(CN)3]2[MII(H2O)2]}n (M = Ni, Co, Mn, Zn, Cu). Nous avons supposé que la faible dimensionnalité et la structure ouverte de ces composés pourraient permettre une (dés)intercalation ionique plus facile et une meilleure capacité d'accueil des ions Al. Nous pouvons également émettre l'hypothèse que la présence d'une enveloppe organique (ligands Tp) dans les chaînes pourrait favoriser des interactions électrostatiques plus faibles entre le cation multivalent inséré et le cadre, et donc une meilleure diffusion. De plus, des comparaisons entre les composés pontés par différents métaux divalents, y compris le zinc inactif, sont destinées à aider à comprendre les effets multiples des métaux pontés sur les composés.Ensuite, nous avons abordé le deuxième sujet basé sur l'acide chloranilique. Il s'agit d'une série de cadres bidimensionnels (2D), car nous souhaitons tirer parti de la haute stabilité de la structure 2D et compter sur les groupes carbonyles potentiels pour réaliser l'intercalation et la désintercalation. En conséquence, les tests préliminaires prouvent la stabilité de cette série de cadres. Étant donné qu'il s'agit d'un projet en cours et que nous n'avons rapporté que les données jusqu'à présent, une investigation plus approfondie de cette série est nécessaire
The first chapter introduces the concept and fundamental characteristics of molecular materials. It highlights their broad applications and the advantages they offer in electrochemical devices, along with an overview of their development in this field. Then, molecular materials are classified in three distinct ways based on different criteria. Each classification's subcategories are systematically explained, highlighting different aspects of molecular materials according to the classification method.Starting from multivalent ion batteries, the second chapter introduces the emerging aluminum ion battery as a storage system with great potential. The advantages of developing aluminum ion batteries are shown from the objective advantages of the natural abundance and price of aluminum itself, and the theoretical electrochemical potential of aluminum. Then, from the two aspects of electrolyte and electrode materials, aluminum ion batteries and their development status are summarized through detailed classification and examples.Therefore, based on our understanding of molecular materials and aluminum ion batteries, we conducted the following two projects:In a seminal work, we reported the lithium-ion storage capabilities of the iron-nickel bimetallic one-dimensional (1D) coordination polymer, {[FeIII(Tp)(CN)3]2[NiII(H2O)2]}n. The result first confirmed the reversible Li+ (de)intercalation in the 1D cyanide-bridged molecular material. This successful attempt in lithium-ion batteries aroused our interest in further exploring the possible insertion of aluminium ions into such one-dimensional cyano-bridge. In this work, we selected ([EMIm]Cl-AlCl3 ionic liquid with the ratio of 1.1:1(AlCl3 : ([EMIm]Cl) as electrolyte, and developed a series of one-dimensional (1D) material with the formula{[FeIII(Tp)(CN)3]2[MII(H2O)2]}n (M=Ni, Co, Mn, Zn, Cu). We expected the lower dimensionality and open framework of these compounds could permit easier ion (de)intercalation and a better Al-ion host capability. We can also hypothesize that the presence of organic shell (Tp ligands) in the chains could favor weaker electrostatic interactions between the inserted multivalent cation and the framework, and thus a better diffusion. Furthermore, comparisons between compounds bridged different divalent metals, including inactive zinc, are intended to help understand the multifaceted effects of bridged metals on compounds.Then, we conducted the second topic based on chloranilic acid. It is a series of 2D frameworks, as we would like to take advantage of the high stability of 2D structure and rely on the potential carbonyl groups to realize the intercalation and deintercation. As a result, the preliminary tests prove the stability of this series of frameworks. Since this is an ongoing project and we have only reported the data so far, further investigation of this series is needed

La vinasse de distillerie, co-produit de l’industrie canne-sucre-alcool-énergie, contient de 5 à 7 g/L d’un acide d’intérêt, l’acide aconitique, au sein d’un milieu complexe comportant d’autres acides organiques, des acides aminés, mais surtout des sels minéraux (chlorures et sulfates) et des colorants, rendant sa purification complexe. Afin d’améliorer les performances du procédé d’échange d’ions, au coeur de cette purification, la résine anionique faible Lewatit S4528 a été caractérisée. Le dosage de la résine et des mesures d’isothermes d’échange d’ions ont permis de définir : la capacité totale du support, l’ordre d’affinité des principaux anions de la vinasse et les coefficients d’échange d’ions associés, de même que la capacité pour l’acide d’intérêt dans cette matrice complexe. L’effet du pH, de la forme du support (sulfate, chlorure et base libre) et de l’éluant ont été étudiés en colonne pour différentes solutions (acide seul, vinasse « modèle », vinasse réelle), permettant de préciser les mécanismes de la purification.Les meilleures conditions (vinasse à pH 4,5, résine sous forme chlorure et élution par HCl 0,5 N) ont abouti à un éluat d’une pureté de 28 %MS avec un rendement global de 61 %. Pour éliminer les principales impuretés qui persistent dans l’éluat (ions chlorure et sulfate et des colorants), l’électrodialyse s’est avérée un procédé très performant en ce qui concerne l’élimination des ions chlorure (proche de 100 %) tandis qu’une étape d’adsorption sur résine polystyrénique XAD16 permet l’élimination de 80 % de la charge colorante de l’éluat acide. Le couplage le plus intéressant associe microfiltration, échange d’ions, électrodialyse et adsorption. Il permet d’obtenir une pureté estimée à 37 % MS, avec un facteur de purification de 3,6 par rapport à la vinasse initiale. Ces travaux ont permis d’améliorer d’un facteur 2,6 la pureté de l’acide par rapport à des études antérieures et de mieux comprendre les mécanismes de sa purification sur résine anionique faible
Cane stillage or vinasse, a byproduct of cane industry, contains from 5 to 7 g/L of aconitic acid, a valuable trivalent carboxylic acid belonging to the second class of building block chemicals. Vinasse also contains a variety of organic compounds (organic acids, amino-acids, colouring matters) and minerals (chlorides, sulphates), which makes purification not straightforward. The objective of this work is to develop the extraction of aconitic acid from stillage, with anion exchange as the heart of the process. In order to improve performances, the main characteristics of the selected anion-exchange resin (Lewatit S4528) are studied. Acid-base dosage and ion-exchange equilibrium experiments allow the total capacity of this support and the ion-exchange coefficients for the major competing anions (aconitate, chloride and sulfate) to be obtained. Separation performances in column are studied for different pH, different solutions (aconitic acid alone, synthetic and industrial stillage) and different resin forms (sulfate, chloride and free- base) in order to elucidate the separation mechanisms.Elution step is also investigated. Best conditions are for stillage at its natural pH (pH 4.5) on the resin under chloride form and HCl 0,5N as the eluant. A 28% DM purity and a 61% global recovery are achieved for aconitic acid in the eluate. Main impurities still remaining are chlorides or sulfates and coloring matter. Homopolar electrodialysis proves successful for removing nearly 100% chlorides from aconitic acid with a limited loss of the acid (< 15%). Adsorption step on a polystyrenic resin (XAD16) of an acidic eluate leads to the retention of 80% of the colorants, with only 12% of the acid lost. At last, the most interesting process combination associates microfiltration, anion-exchange, electrodialysis and adsorption. Purity is 37% MS, namely 3.6 higher than the original vinasse. This work enables aconitic acid purity to be improved by a factor of 2.6 compared with prior studies and to have a better comprehension of the mechanisms involved in its purification on weak anionic resin

Li+ ion batteries have been the mainstay of high energy storage devices that have revolutionized the operating life time of consumer electronic devices for the past two decades. However, there is a steady increase in demand for energy storage devices with the ability to store more energy and deliver them at high power at low cost, without comprising safety and lifetime. Li-ion batteries have had significant challenges in increasing the amount of stored energy without affecting the overall lifetime and the ability to deliver stored energy. In order to store and deliver more energy, more lithium ions need to be inserted and extracted from a given electrode (cathode or anode). Upon inserting a large number of Li ions, the crystal lattice of the materials undergo severe mechanical distortions, leading to un-desirable structural changes. This results in underutilization of theoretical energy storage capacities of the electrodes and early failure of the batteries owing to instabilities in the electrode materials. Unlike monovalent Li+ ions, multivalent rechargeable batteries offer a potential solution to the above problems. Multivalent cations, such as Ca2+, are doubly-ionized as opposed to Li+ which is a monovalent cation. The advantages of using Ca2+ ions instead of Li+ ions are multifold. Due to the doubly-ionized nature, only half the number of Ca2+ ions need to be inserted and extracted from a given electrode to store and deliver energy from a high capacity cathode as compared to Li+ ions. This reduces the probability of lattice distortion and un-desirable structural changes, further leading to increased utilization of high theoretical energy storage capacities of the electrodes (cathode and anode). The use of Ca2+ ions also helps in delivering twice the amount of current density as compared to Li+ ions due to its doubly ionized nature. In this work, a set of eight metal hexacyanoferrate compounds were synthesized using the following metal ions: Ba2+, Mn2+, Zn2+, Co2+, Fe3+, Al3+, Sn4+, Mo5+. The resulting metal hexacyanoferrate compounds were subjected to physical characterization using scanning electron microscope (SEM) and powder x-ray diffraction (XRD), to determine physical properties such as size, morphology, unit cell symmetry and unit cell parameters. This was followed by electrochemical characterization utilizing cyclic voltammetry and galvanic cycling, to determine the specific capacity and kinetics involved in the transport of Ca2+ ions to store charge. Optical characterization of the metal hexacyanoferrates using Fourier transform infrared (FTIR) spectroscopy, allowed for the identification of metal-nitrogen stretching frequency, which was used as a measure of the strength of the metal-nitrogen bond to understand the role of the above mentioned metal ions in electron density distribution across the unit cell of the metal hexacyanoferrates. The specific capacity utilization of the metal hexacyanoferrates, when compared to the electronegativity values (Xi) of the above mentioned metal ions, the σ- parameter, and the metal-nitrogen stretching frequency (v), revealed an empirical trend suggesting that the materials (FeHCF, CaCoHCF and CaZnHCF) that possessed intermediates values for the above mentioned parameters demonstrated high capacity utilization (≥50%). Based on these empirical trends, it is hypothesized that a uniform distribution of electron density around a unit cell, as reflected by intermediate values of the electronegativity (Xi) of the above mentioned metal ions, the σ-parameter and the metal-nitrogen stretching frequency (v), results in minimal electrostatic interactions between the intercalating cation and the host unit cell lattice. This results in relatively easy diffusion of the cations, leading to high specific capacity utilization for metal hexacyanoferrate cathodes. These parameters may be used to select high efficiency cathode materials for multivalent batteries.

The electrochemical, thermal and structural properties of polyethylene oxide (PEO) based polymer electrolytes containing multivalent ions were investigated. The phase diagram for the PEO:Ca(CF3SO3)2 system was determined by x-ray diffraction and differential scanning calorimetry techniques. Precipitation of the salt from the system at high temperatures was directly observed by variable temperature x- ray diffraction. This was ascribed to a negative entropy of dissolution of the salt in the polymer. A new crystalline complex PEO6Ca(CF3SO3)2, which exhibits a phase transition between two polymorphic forms was observed. The temperature dependence of ionic conductivity was related to the phase diagram. Redox behaviour of the PEO:Nil2 system was probed. Motion of the Ni(II) species through the system was extremely slow as evidenced by the low effective diffusion coefficient (1.82 x 10 11 cm 2s−1) and cationic current fraction (F+ < 0.1). Deposition of nickel from the polymer was characterised by instantaneous nucleation followed by three dimensional diffusion controlled growth. Investigation of the redox behaviour of the PE0:Eu(CF3SO3)3 system indicated that reduction of Eu3+ followed an ec mechanism. Evidence was obtained for extremely slow diffusion of Eu3+ containing species (D[sub]eff ~ 3.66 x 10 −16cm2s−1) through the system and slow kinetics of electron transfer. Thermal studies of the PEO:Co(SCN)2 system indicated that the glass transition temperature (Tg) was grossly elevated by the presence of Co(SCN)2 in the polymer. The absence of a crystalline PEO:Co(SCN)2 complex was ascribed to the high Tg which leads to slow crystallisation kinetics. UV-visible spectra indicated that the Co2+ ion was tetrahedrally coordinated in the system at low salt concentrations. The structure of the PEO3NaClO4 crystalline complex was reported as a subsidiary study.

Les aluminosilicates poreux cristallins tels que les zéolithes cationiques de type faujasite sont largement étudiés en raison de leurs propriétés d’adsorption, d’échange ionique et de catalyse, ce qui leurs valent d’être engagées dans de nombreuses applications industrielles, qui font intervenir de plus en plus de cations multivalents (détergents/ adoucissants, craquage catalytique, décontamination,...). Ces différentes applications industrielles ont en commun les propriétés d’adsorption, résultant d’une part de la taille de leurs pores du même ordre de grandeur que les espèces introduites, et d’autre part de leur composition chimique qui conduit à des charges de charpente, à l’origine de sites de forte interaction ou de répulsion localisés. Dans ces applications, les zéolithes sont hydratées. L’eau est associée aux processus mis en jeu et influence ainsi les autres propriétés du matériau. La modélisation moléculaire est un outil de choix pour prédire et comprendre les propriétés microscopiques du matériau hydraté, qui sont difficilement accessibles expérimentalement. Ce travail de modélisation porte plus précisément sur le comportement des cations multivalents dans les matériaux zéolithiques hydratés, en collaboration avec des expérimentateurs. Notre étude sur une zéolithe faujasite Y a permis tout d’abord de clarifier la migration des cations sodium au cours de la déshydratation, et de prédire la localisation cationique dans le matériau hydraté en présence d’ions bivalents. De plus, nous avons montré qu’il était possible de rationaliser conjointement la migration des cations et les déformations structurales dans la faujasite au cours de l’adsorption d’eau. À cet effet, nous avons développé une méthode d’analyse pour la localisation cationique. La bonne performance d’un champ de force polarisable démontrée au cours de ce travail ouvre la voie à l’étude de la dynamique globale du système, en permettant le suivi de la migration cationique simultanément à la déformation de la charpente. A plus long terme, cette approche pourra être étendue à d’autres ions multivalents d’intérêt (terres rares, éléments f, ...)
Porous crystalline aluminosilicates such as cationic zeolites, are widely studied because of their adsorption, ion exchange and catalytic properties, which explain their use in many industrial applications. Examples of the latter, which involve in particular multivalent cations, include detergents/softeners, catalytic cracking, or decontamination. Such industrial applications of zeolites all exploit their adsorption properties, which vary as a function of the pore size, comparable to the adsorbing molecules, or chemical composition, which results in charges within the framework, and in turn strong binding or repulsive sites. Importantly, in such applications zeolites are hydrated. Water is involved in the microscopic processes and thus influences all properties of the material. Molecular modeling is a weapon of choice to predict and understand the microscopic properties of the hydrated material, which are difficult to access experimentally. More precisely, the present modeling work deals with the behavior of multivalent cations in hydrated zeolites, in collaboration with experimentalists. Our study on zeolite Y faujasite first allowed us to clarify the migration of sodium cations upon dehydration and to predict the cation localisation in the hydrated material in the presence of divalent cations. Furthermore, we rationalized the coupled migration of cations and deformation of the framework upon water adsorption. To this end, we have developed a new method for the analysis of cation localization. The good performance of a polarizable force field demonstrated here paves the way for the study of the dynamics of the whole system, following in particular the simultaneous migration of cations and deformation of the framework. Such an approach could be later extended to other multivalent ions of industrial interest (rare Earths, f-block elements, ...)

The first part of this work deals with the determination of the thermodynamic parameters for the complexation of lanthanide cations (La3+, Pr3+ and Nd3+) with Cryptand-221 and Cryptand-222 in acetonitrile and propylene carbonate at 298.15 K. The complexation process between these cations and these ligands in these solvents is enthalpy-controlled. The higher stability observed for these cations and these ligands in propylene carbonate with respect to acetonitrile is attributed to the increase in entropy observed for the complexation reaction in propylene carbonate. Enthalpies of solution of lanthanide and lanthanide cryptates are reported. These data are used to derive single-ion enthalpies of transfer of La3+, Pr3+ and Nd3+ from propylene carbonate to acetonitrile based on the Ph4AsPh4B convention. The results show that the cryptate conventions are not valid for the calculation of single-ion values for the transfer of tervalent lanthanide cations among dipolar aprotic media. Enthalpies of coordination of lanthanide(III) cryptates in the solid state are calculated. The second part of this study aims to investigate the properties of the synthetic macrocyclic ligands such as Cryptand-222 and 18-Crown-6 towards molecules of biological importance. Stability constants (hence free energies), enthalpies and entropies of complexation of a series of DL-amino acids with 18-Crown-6 and Cryptand-222 in methanol and ethanol, as obtained from titration calorimetry, are reported. No significant variations are found in the free energies of complexation of the different amino acids and these two ligands in these solvents as a result of an enthalpy-entropy compensation effect. This effect is for the first time shown in complexation reactions involving crown ethers and cryptands. The thermodynamic parameters of transfer of amino acids and their complexes with 18-Crown-6 and Cryptand-222 from methanol to ethanol have been calculated. Possible correlations between complexation and transfer data for the amino acids, the ligands and the amino acid-macrocyclic ligand complexes are investigated. The implications of these results to processes of biological importance are discussed. As a continuation of this study, the possibility of selectively extracting amino acids from methanol by polymeric resins containing crown ethers as anchor groups is investigated.

Nous avons etudie des solutions de poly acide methacrylique (pma) dans l'eau en presence et en absence de cuivre(ii). Dans l'eau pure, le pma presente une transition conformationnelle forme compacte pelote expansee pendant sa neutralisation. L'etude du polymere non ionise dans sa forme compacte par diffusion du rayonnement montre que le polymere est en bon solvant a temperature ambiante. Le facteur de forme indique une structure gaussienne a grande echelle, alors qu'une decroissance en 1/q#3 est observee a grand q. Nos resultats suggerent que la forme compacte est due a l'existence de portions de chaine localement repliees, et non a un collapse global de la chaine. Lorsqu'on augmente le degre de neutralisation, la fonction de diffusion presente le classique pic de correlation des polyelectrolytes. La variation de la position du pic avec la concentration dans le regime dilue et semi dilue est conforme aux predictions theoriques. En revanche, l'evolution en fonction du degre de neutralisation presente une discontinuite, manifestation de la transition conformationnelle. Les theories de champ moyen etablies pour le regime concentre ne permettent pas de decrire les fonctions de diffusions experimentales. En presence de cuivre, les resultats que nous avons obtenu par ph-metrie, viscosimetrie et spectroscopie confirment la stoechiometrie 2 carboxylates par ions cuivre proposee dans la litterature. Nos resultats rpe mettent en evidence l'existence de complexes binucleaires. La comparaison avec d'autres poly acides carboxyliques fait apparaitre clairement les relations entre la nature du complexe forme et la densite de charge et les proprietes intrinseques du polymere. L'etude structurale par diffusion de la lumiere et des rayons x montre que le cuivre se fixe de facon intramoleculaire dans le regime de concentration etudie. Les fonctions de diffusions obtenues ne presentent pas de pic aux faibles degres de neutralisation, domaine de fixation du cuivre. Dans cette region, la fixation du cuivre entraine un collapse global de la chaine

Biological cells and subcellular organelles are surrounded by membranes to form compartments performing specialized functions. Adsorption or partitioning of biologically active compounds into the membrane is the first step in the process of modification of cell function. This work is concerned with the problem of distribution of charged molecules between water and electrically charged membrane surface and between water and octanol. Part I of this thesis is focused on the electrostatic interactions taking place between charges on the membrane and ions present in the aqueous region of the membrane/water interface. The objective was to explore theoretically the origin of anomalous behavior of Ruthenium Red (RuR), a positively charged hexavalent ion. It was discovered in studies of RuR adsorption to negatively charged membranes that within the framework of the Gouy-Chapman theory of the membrane/water interface, RuR behaves as an ion with effective charge less than its physical charge. Moreover, the effective charge was found to be dependent on the density of electric charge at the membrane surface. Two theoretical models of the interfacial region were examined: the Rod Model and the Maximum Density Model. The Rod Model takes into account steric constraints imposed on RuR at the vicinity of the membrane surface. The Maximum Density Model attempts to account for non-ideal behavior by including repulsive interactions. These theoretical studies illustrate the consequences of finite size and ion-ion interactions of adsorption of large molecular ions to electrically charged membrane surfaces. Part II is an experimental study whose objective was to determine the partition coefficient of the negatively charged 2,3,4,5-tetrachlorophenol (TeCP) between water and octanol. The study was based on spectrophotometric measurements of the equilibrium concentrations of TeCP in water and octanol as a function of pH. The octanol/water partition coefficient for both the non-ionized and ionized species of TeCP were determined. It was found that the partition coefficient of ionized TeCP to lipid membrane is about 400 times greater than that for octanol. This result supports the hypothesis that the octanol/water partition coefficient of ionized chlorophenols cannot be used for predicting their distribution between water and lipid-bilayercontaining elements of the environment.

Les films muticouches de polyélectrolytes sont des revêtements organiques d’épaisseur allant du nanomètre au micromètre. Ils peuvent être classés en deux catégories aux propriétés distinctes, selon le régime de croissance de leur épaisseur : linéaire ou exponentiel. L’objectif essentiel de cette thèse a été d’approfondir la compréhension des interactions à l’origine de la formation de ces films et de leur structure interne. Le premier volet a permis d’établir une relation entre le régime de croissance des films formés à partir d’un couple de polyélectrolytes donné et l’enthalpie de la réaction de complexation du même couple en solution. La seconde partie a consisté en l’étude par voltampérométrie cyclique des interactions entre le ferrocyanure et un film multicouche à croissance exponentielle. Sur les bases de ces résultats, la construction par la technique de dépôt réactif et la caractérisation de films composites organiques-inorganiques ont enfin été réalisés
Polyelectrolyte multilayer films are organic coatings with thicknesses ranging from nanometers to micrometers. The thickness of these films can increase either linearly or exponentially with the number of deposition steps. The aim of this thesis was to better the comprehension of the internal structure of these films, as well as the interactions that lead to their formation. The first part of this work allowed to establish a relation between the growth regime of a film built with a given polyelectrolyte pair and the complexation enthalpy of the same pair in solution. The second part was a study of the interactions between ferrocyanide and an exponential growing polyelectyrolyte multilayer film by cyclic voltammetry. The last part, taking advantage of the results yielded by the other parts, consisted in the build-up and characterization of organic-inorganic composite films, using a reactive deposition method

This study investigates a multilingual, multi-genre data set of 13 post-9/11 popular culture videos, produced by performative artists from across global society, which use digital media aesthetics to defy hegemonic narratives relating to Islam and the War on Terror. The languages represented across the 13 texts are English, French, Spanish and Arabic; and the popular culture genres are hip-hop, comedy, punk and parkour. The texts are grouped thematically for analytical purposes into the following categories: 9/11, War on Terror, Clash of Civilisations, and Palestine. Using the sociological manifestation of narrative theory (Baker 2006, Somers 1994) as the conceptual framework, I firstly conduct a narrative analysis of the texts focusing on themes of temporality; character/identity; and multivalence, i.e. the co-existence of seemingly contradictory narratives within a single text (Stroud 2002). I argue that a combination of aesthetics and multivalence is deployed in all the videos, despite their creative and linguistic diversity, which functions to arrest viewers out of uncritical immersion in their normative (hegemonic) narrative environment, and open a space in the affective present for new meanings and values to enter. This technique or affective practice, which I term ‘aesthetic shock’, addresses a widespread critique of socio-narrative theory; namely, the failure to account for how social agents might subscribe to new narratives that contradict their existing worldview. Secondly, the socio-narrative framework is supplemented with recent scholarship on affect (Berlant 2011, Butler 2004) and Deleuzian philosophy (1987). This permits a deeper understanding of the texts as indicative of an epistemological groundswell that is symptomatic of our unfolding moment in history, whereby contradiction and aesthetics emerge as key narrative tools for resistance to the post-9/11 hegemonic order. The two models are connected from a translation studies vantage point by the notion of ‘renarration’ (Baker 2008), offering a unique angle on the flows, patterns of exchange, and evolving identity constructs in the digital media context. Following detailed exploration of the texts and their production contexts, consistent features are drawn out in an attempt to identify emerging patterns between them. These findings include the affective practice of what I term ‘conscious individualism’, the creation of intimate publics (Berlant 2011), and a united, pluralised front against the neoliberal economic agenda for which prominent public narratives such as Samuel Huntington’s reductive ‘Clash of Civilisations’ thesis (1996) act as a smokescreen. Ultimately, it is argued that the texts should be seen as deterritorialising sites of aesthetic activism; a means for the non-elites masses across global society to creatively capitalise on the affordances of the digital era, to assert themselves against oppressive cultural narratives and affirm new modes of thinking and being the world. Expressions of political resistance such as the 13 texts analysed in this study are becoming more visible and more vital across different linguacultures as the rationalist nation-state paradigm loses currency, evoking the possibility of futures other than that of capitalist progress. I contend that we must pay close attention to such narratives –both their message and their medium – if we are to achieve a more constructive and nuanced appreciation of the chaotic and contradictory world in which we live.

碩士
國立臺灣大學
物理研究所
97
This thesis is focus on the studying of DNA behaviors in nanoconfinement. In nano/micro fluidic systems, the surface to volume ratio becomes too large to neglect the electrokinetics on the surface. And in nanoconfinement, DNA is forced to be confined to a limit region. This changes the conformation and transport mechanism of DNA and generates lots of novel phenomena. We studied two separate parts: DNA condensation induced by multivalent ions and DNA transport induced by electric field in nanostructures. DNA condensation is a well-known phenomenon. The free-coil-chain-like conformation of DNA transforms to condensed toroid or rod in the existence of multivalent ions. In our experiment, we studied the influence of confinement to DNA condensation. We found that DNA condensation process is slower in strong confinement than in free solution in de Gennes regime. This can be partly explained by the increasing relaxation time in strong confinement. The second part is DNA transport in nanostructures induced by electric field. In free solutions, DNA transport under electric field can be fully explained by electrophoresis. Though in nanostructures, DNA transport is more complicated than that in free solutions. EOF, concentration polarization, surface conductance, DNA trapping, and lots of other effect should be taken into considerations. We categorize DNA transport in nanostructures induced by electric field and try to clarify the main factors that participate in. In free solutions or microchannels, DNA transport is dominated by electrophoresis. However, in nanostructures EOF may strong enough to dominate the transport direction. And in stronger confinement, we have to take EOF of the second kind and concentration polarization into considerations.

Trivalent lanthanide metals (Ln 3+ ) are among the most spectroscopically active ions in the periodic table and are characterized by their exceptional ability to absorb and emit light in the ultraviolet, visible and near infra-red regions of the electromagnetic spectrum. These ions are sensitive to the nature of their ligands, as has been evidenced from their spectral properties in different environments. In an effort to predict the behaviour of lanthanide ions in different environments, solvated Ln 3+ ions in clusters, Ln 3+ (solvent) n , were investigated as a model system. Cluster studies provide an ideal means of monitoring progressive changes in the properties of the lanthanide ions with cluster size increases. The electronic, energetic and thermodynamic properties of Ln 3+ (H 2 O) n and Ln 3+ (CH 3 CN) n clusters were simulated using a combination of quantum chemistry calculations, model potential development and Monte Carlo simulations, paying close attention to possible cluster-to-bulk transitions. The properties of small Ln 3+ (H 2 O) n clusters obtained from quantum chemistry calculations indicate, much akin to other multi-valent M q+ (H 2 O) n clusters, that the metal ion-water interactions are predominantly electrostatic. Mutual polarization of both the ion and the water molecules accounts for the large Ln 3+ (H 2 O) n cluster binding energies and the resulting structural properties of the clusters. The quantum chemistry results were the basis for designing and parameterising polarizable model potentials for use in Monte Carlo simulations. The simulations revealed that bulk-like properties of Ln 3+ (H 2 O) n clusters, namely first-shell coordination numbers and bulk thermodynamic properties, are obtained at very large cluster sizes (n > or = 64), thus showing that cluster studies are a good model for studying bulk solvation. The Ln 3+ (H 2 O) n cluster binding enthalpies were found to be quite large, even at small cluster size, implying that these species should be stable under experimental conditions. However, small clusters have rarely been observed experimentally when they contain protic solvents and charge-reduced clusters, where the metal loses its 3+ charge, are observed instead. Thus, Eu 3+ (H 2 O) n cluster deprotonation was investigated as a possible explanation for the lack of experimental observation of small Ln 3+ (H 2 O) n clusters. The small clusters were found to favour loss of (solvated) hydronium ions from the cluster, explaining the experimentally-observed, charge-reduced clusters. Only recently (June 2006) was the experimental observation of large Ln 3+ (H 2 O) n clusters (n > 15) reported. This is consistent with our prediction that deprotonation becomes less favourable with cluster size. Finally, investigation of Ln 3+ (CH 3 CN) n clusters, using a similar methodology, reveals that formation of these clusters is also energetically favourable and that convergence to bulk, structural and thermodynamic properties are obtained at smaller cluster sizes than those observed in water clusters. Given that the thermodynamic properties of Ln 3+ (CH 3 CN) n and large Ln 3+ (H 2 O) n clusters have yet to be determined, the results herein may serve as benchmarks for future experimentation.