Abstract Heavy metals are used in many industrial processes and their cations are either valuable or environmentally harmful to discharge in wastewater. Thus, it is necessary to separate heavy metals in wastewater treatment. Amongst several technical methods of separation, use of permeable membranes is an important one. For separation processes, membranes can be selective towards a target heavy metal cation either against mono-valent common cations or against other similar heavy metal cations. Synthesis of selective permeable membranes for separation purposes is an area of continuous research to meet specific needs in different applications. One of the common applications of selective separation by a permeable membrane is cation/anion separation processes using cation exchange and anion exchange membranes. Another application of selective permeable membranes is the separation of mono-valent cations from other higher valence cations. Some researchers have focused on specific selective separation of heavy metal cation from other heavy metal cations having the same valent charge. Some use chelating particulates dispersed in a neutral polymeric membrane matrix and others applied a thin chelating film on the surface of a commercial cation exchange membrane. In this work, the synthesis of novel permeable selective membranes and their use for selective separation between two di-valent heavy metal cations is presented. Three different sets of membranes were prepared in non-imprinted and imprinted forms. The ion imprinted membranes form is prepared by pre-reacting the target metal ion with the selective chelating monomer before applying in situ polymerization step, and in the non-imprinted membranes form this step is not considered. Their morphological and chemical structures were determined and their separation performances were investigated using a diffusion dialysis technique. The first membrane (non-imprinted polyvinylidene fluoride-divinylbenzyl-triethylenetetramine (PVDF/diVB-TETA) and Cu-imprinted PVDF/diVB-TETA-Cu forms) was prepared by in situ polymerization of the chelating monomer divinylbenzyl-triethylenetetramine diVB-TETA (or diVB-TETA-Cu) within a PVDF substrate, using a divinylbenzene cross-linker. Fourier transform infrared FT-IR spectroscopy showed the successful in situ polymerization of the chelating monomer within the PVDF texture. The permeation study showed that the ion-imprinted membrane has a Cu2+ selectivity factor of 3.78, while the non-imprinted membrane has a Cu2+ selectivity factor of 1.65. In addition the Cu2+ permeation flux in the imprinted membrane is 3.9 time that in the non-imprinted membrane For the second membrane, the synthesis is similar to the first membrane for both non-imprinted and imprinted forms (polyvinylidene fluoride-divinylbenzyl-triethylenetetramine-N,N'-methylenebis(acrylamide) (PVDF/diVB-TETA-N) and PVDF/diVB-TETA-N-Cu respectively), except that the used cross-linker was N,N'-methylenebis(acrylamide). In addition, sodium 4-vinylbenzyl sulfonate was added in selected percentages, (5-15% mol), to enhance the permeation flux. FT-IR spectroscopy analysis of the prepared membranes confirmed the chemical structure of diVB-TETA-N and sulfonate group into PVDF. Permeation and selective separation studies for the prepared membranes showed that the ion-imprinted membrane has a higher selectivity for copper permeation over the non-imprinted membrane. However imprinted membrane showed a lower flux for the permeated cations than that of the non-imprinted membranes The addition of the sulfonate groups to the prepared membranes enhanced the flux of the permeated cations, but the copper selective permeation decreased for both types (non-imprinted and ion-imprinted). Moreover, the ion-imprinted membrane PVDF/diVB-TETA-N-Cu showed a lower flux for the permeated cations than that of the non-imprinted membranes PVDF/diVB-TETA-N. Selective separation factors decreased to unity when the content of the sulfonate groups increased to 15% mol. Ion imprinted membrane prepared with 10% of sulfonate group showed optimum copper selectivity factor (α = 30304) and permeation flux for copper (0.4949 μmol cm‒2 h‒1) The third membrane (non-imprinted Selemion TM cation exchange membrane-divinylbenzyl-triethylenetetramine (CMV-S/diVB-TETA) and ion-imprinted CMV-S/diVb-TETA-Cu forms) was prepared by in situ polymerization of the chelating monomer, diVB-TETA (or diVB-TETA-Cu), on the surface of the commercial cation exchange membrane, Selemion, using divinylbenzene as cross-linker. FT-IR spectroscopy confirmed the chemical structure of the chelating polymer on the CMV-S membrane surface. Permeation study showed that ion-imprinted CMV-S/diVB-TETA-Cu membrane reached high separation factor (α = 17), yet the flux is low (0.0391 μmol cm‒2 h‒1). Non-imprinted CMV-S/diVB-TETA membrane of thickness (0.115±0.005 mm) using cross-linker (10% DVB) showed reasonable copper selectivity factor (α = 2.723) and permeation flux (0.433 μmol cm‒2 h‒1) / Thesis / Doctor of Philosophy (PhD)

Filmes inorgânicos de ZrO2 e filmes híbridos orgânico-inorgânicos de ZrO2-PMMA, preparados pelo método sol-gel, foram estudados como protetores contra a corrosão de aço inoxidável em meio ácido. Os sóis foram preparados a partir de uma solução submetida à irradiação de ultra-som e contendo o alcóxito metálico correspondente como precursor, álcool como solvente e ácido acético glacial como agente quelante para modificar a reatividade do alcóxito metálico. Várias concentrações de PMMA foram adicionadas aos sóis e estes foram caracterizados através de reometria, espectroscopia na região do infravermelho (FTIR), calorimetria explanatória diferencial (DSC) visando estudar a evolução de suas características morfológicas durante o envelhecimento. Os filmes de ZrO2 e ZrO2-PMMA foram depositados, utilizando-se a técnica de imersão, sobre lâminas de aço inoxidável 316L (AISI 316L), densificados a 200&#176C e o tempo de tratamento térmico foi variado de 5 a 180 minutos. Os filmes foram caracterizados por espectroscopia de reflexão especular na região do infravermelho; a morfologia, composição e textura superficiais foram determinadas por microscopia eletrônica de varredura (MEV), dispersão de energia de raios X (EDS) e perfilometria, respectivamente. curvas de polarização potenciodinâmica a 1 mVs-1 foram usadas para estudar a eficiência dos diferentes recobrimentos na proteção do AISI 316L contra a corrosão em soluções de H2SO4 0,5 mol.L-1. Os resultados mostram que os filmes híbridos ZrO2-PMMA aumentam em média 30 vezes o tempo de vida do substrato em relação aos filmes puramente inorgânicos. / ZrO2 inorganic and ZrO2-PMMA hybrids organic-inorganic films, obtained by the sol-gel method, were studied in order to determine their properties as protective layers against corrosion of stainless steel in acid media. The sol was prepared from a sonocatalyzed solution containing the appropriate metal alkoxide as precursor, alcohol as solvent, and glacial acid acetic as chelant agent to modify the reactivity of the metal alkoxide and PMMA was added into these sols. Reology, infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) were employed to determine the evolution of structural changes during aging time. The ZrO2 and ZrO2-PMMA films were deposited on stainless steel by dip-coating technique and heat treated at 200&#176C at times of heating ranging from 5 to 180 minutes. The films were characterized by FTIR reflection spectroscopy, scanning electronic microscopy, X-ray dispersive energy and profilometry to determine the surface morphology, composition and texture, respectively. Potentiodynamic polarization curves (PPC) at 1 mVs-1 were used to study the efficiency on the protection of AISI 316L against corrosion in H2SO4 0,5 mol.L-1, showing that ZrO2-PMMA increase in a factor up 30 the life time of substrate.

Filmes inorgânicos de ZrO2 e filmes híbridos orgânico-inorgânicos de ZrO2-PMMA, preparados pelo método sol-gel, foram estudados como protetores contra a corrosão de aço inoxidável em meio ácido. Os sóis foram preparados a partir de uma solução submetida à irradiação de ultra-som e contendo o alcóxito metálico correspondente como precursor, álcool como solvente e ácido acético glacial como agente quelante para modificar a reatividade do alcóxito metálico. Várias concentrações de PMMA foram adicionadas aos sóis e estes foram caracterizados através de reometria, espectroscopia na região do infravermelho (FTIR), calorimetria explanatória diferencial (DSC) visando estudar a evolução de suas características morfológicas durante o envelhecimento. Os filmes de ZrO2 e ZrO2-PMMA foram depositados, utilizando-se a técnica de imersão, sobre lâminas de aço inoxidável 316L (AISI 316L), densificados a 200&#176C e o tempo de tratamento térmico foi variado de 5 a 180 minutos. Os filmes foram caracterizados por espectroscopia de reflexão especular na região do infravermelho; a morfologia, composição e textura superficiais foram determinadas por microscopia eletrônica de varredura (MEV), dispersão de energia de raios X (EDS) e perfilometria, respectivamente. curvas de polarização potenciodinâmica a 1 mVs-1 foram usadas para estudar a eficiência dos diferentes recobrimentos na proteção do AISI 316L contra a corrosão em soluções de H2SO4 0,5 mol.L-1. Os resultados mostram que os filmes híbridos ZrO2-PMMA aumentam em média 30 vezes o tempo de vida do substrato em relação aos filmes puramente inorgânicos. / ZrO2 inorganic and ZrO2-PMMA hybrids organic-inorganic films, obtained by the sol-gel method, were studied in order to determine their properties as protective layers against corrosion of stainless steel in acid media. The sol was prepared from a sonocatalyzed solution containing the appropriate metal alkoxide as precursor, alcohol as solvent, and glacial acid acetic as chelant agent to modify the reactivity of the metal alkoxide and PMMA was added into these sols. Reology, infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) were employed to determine the evolution of structural changes during aging time. The ZrO2 and ZrO2-PMMA films were deposited on stainless steel by dip-coating technique and heat treated at 200&#176C at times of heating ranging from 5 to 180 minutes. The films were characterized by FTIR reflection spectroscopy, scanning electronic microscopy, X-ray dispersive energy and profilometry to determine the surface morphology, composition and texture, respectively. Potentiodynamic polarization curves (PPC) at 1 mVs-1 were used to study the efficiency on the protection of AISI 316L against corrosion in H2SO4 0,5 mol.L-1, showing that ZrO2-PMMA increase in a factor up 30 the life time of substrate.

L’objectif de cette thèse est la synthèse de composés de manganèse et de matériaux hybrides qui soient intéressants du point de vue bioinorganique et magnétique. Pour accomplir ce but, nous avons découpé la stratégie en trois étapes constituant les différents chapitres de ce manuscrit :(a) Synthèse et caractérisation des composés moléculaires de manganèse et l’étude de leurs propriétés magnétiques.Nous avons réussi à obtenir la structure cristalline des vingt-trois nouveaux composés de Mn de différentes nucléarités, d’état d’oxydation II, III ou IV. Nous avons étudié les propriétés magnétiques de ces composés et nous avons établi des corrélations magnéto-structurales. Les composés de MnII ont été aussi étudiés par spectroscopie RPE.(b) Synthèse et caractérisation des matériaux hybrides basés sur des composés moléculaires de manganèse insérés dans de la silice mésoporeuse. Les composés moléculaires sélectionnés ont été insérés dans de la silice mésoporeuse (du type MCM-41). Les complexes de Mn dans les supports ont été caractérisés par ATG, XPS, ICP-OES, spectroscopie IR et mesures magnétiques. (c) Étude des propriétés catalytiques des composés moléculaires et des matériaux hybrides.Une famille de composés moléculaires obtenus dans cette thèse sont des modèles structuraux et fonctionnels de la catalase à Mn, une enzyme présente dans certaines bactéries, ayant des propriétés antioxydantes (H2O2 « scavenger »). L’activité catalase pour ces composés et les matériaux hybrides dérivés a été étudiée dans l’acétonitrile et dans l’eau. / The main objective of this work is the synthesis of manganese compounds and hybrid materials that may be relevant from a bioinorganic and magnetic point of view. The developed strategy comprises three main steps that form different sections in this thesis:(a) Synthesis and characterization of molecular manganese compounds and study of the magnetic propertiesThe crystal structure of twenty-three new Mn compounds of different nucleartities were obtained in which the Mn oxidation state is II, III, or IV. The magnetic properties of all these compounds were profoundly studied and they have been rationalized with their structural and electronic parameters. The MnII compounds were also studied with EPR spectroscopy. (b) Synthesis and characterization of hybrid materials based on molecular manganese compounds inside mesoporous silica.Selected molecular compounds were inserted inside mesoporous silica (MCM-41 type). The Mn complexes inside the supports were characterized with TGA, XPS, ICP-OES, IR spectroscopy, and magnetic measurements.(c) Study of the catalytic properties of both molecular compounds and hybrid materials.A family of the molecular compounds obtained in this work are structural and functional models of the Mn catalase, an enzyme found in some bacteria with antioxidant properties (H2O2 scavenger). The catalase activity for these compounds and the hybrid materials was studied in acetonitrile and water.

Nous avons développé un système de transfert des surfaces monocristallines préparées sous ultra-haut vide (UHV) vers un milieu électrolytique pour effectuer des mesures voltampérométriques. Ce système original très compact comprend une valise sous vide et une cellule électrochimique dédiée. Le système a été testé avec succès sur des surfaces monocristallines de platine, en particulier la surface Pt(111) très sensible à la qualité de la préparation sous UHV. Puis nous avons utilisé ce système pour caractériser les propriétés électrochimiques du système Pt/W(111) avec d'une part l'effet des contraintes élastiques pour les couches ultra-minces planaires de Pt épitaxié ainsi que la stabilité en milieu électrolytique de nano-pyramides obtenues par déstabilisation en température des surfaces Pt/W(111). Ce travail ouvre des perspectives intéressantes pour l'étude électrochimiques des surfaces modèles préparées sous UHV. / In this work, we developed a system for transferring single crystal surfaces prepared in ultra-high vacuum (UHV) to an electrolytic medium where voltammetric measurements are carried out. This unique system includes a compact vacuum chamber and its dedicated electrochemical cell. The system was successfully tested on platinum single-crystal surfaces; in particular the Pt (111) surface which is well known for it's sensitive to the quality of the preparation under UHV. Then we used this system for characterizing the electrochemical properties of the Pt / W (111) system, both the effect of elastic strain of ultrathin epitaxial planar Pt films and the stability of nano-pyramids obtained after a temperature annealing of the planar Pt / W (111) system. This work opens up interesting perspectives for the study of electrochemical model surfaces prepared in UHV.