La préparation de briques élémentaires de pillar[5]arènes « clickables » nous ont permis de construire des édifices moléculaires complexes, en greffant différents groupements fonctionnels autour du coeur macrocyclique. Dans ce contexte, des nouveaux dérivés du pillar[5]arène présentant des propriétés cristaux-liquides ont été synthétisés en greffant du p-dodecyloxybenzoate ou encore des dendrons de type percec. D’autres part, des dérivés pillarèniques portant des unités de porphyrines ont été préparés à partir du squelette « clickable » pillar[5]arène et de porphyrines de Zinc portant des fonctions alcynes vrai. Les études de ce système par RMN du proton à des températures variables ont permis de mettre en évidence un équilibre conformationnel dynamique conduisant au repliement des molécules. Ceci a été expliqué par une complexation intramoléculaire des porphyrines de Zinc par les groupements 1,2,3-triazole. Finalement un support « clickable » detype [2]rotaxane comportant une porphyrine base libre comme bouchon, a été préparé et ensuite fonctionnalisé par dix porphyrines de Zinc permettant l’obtention d’un dispositif supramoléculaire photoactif. / Clickable pillar[5]arene building blocks have been used for the efficient grafting of peripheral subunits onto the macrocyclic core. New liquid-crystalline pillar[5]arene derivatives have been prepared by grafting either p-dodecyloxybenzoate groups or percec-type dendrons on the macrocyclic scaffold. On the other hand, pillar[5]arene derivatives bearing peripheral porphyrin subunits have been efficiently prepared from the clickable pillar[5]arene building block and Zn(II)-porphyrin derivatives bearing a terminal alkyne function. Owing to an intramolecular complexation of the peripheral Zn(II)-porphyrin moieties by 1,2,3-triazole subunits, an original dynamic conformational equilibrium leading to a folding of the molecules has been evidenced by variable temperature 1H NMR studies. Finally, a clickable [2]rotaxane scaffold incorporating a free-base porphyrin stopper has been prepared and functionalized with ten peripheral Zn(II)-porphyrin moieties to afford a sophisticated photoactive supramolecular device.

Ce travail de thèse a été dédié à l’élaboration et l’étude de nouveaux matériaux hybrides obtenus par la fonctionnalisation de molécule-aimants (en anglais single-molecule magnets, SMMs) et de complexes à transfert d’électron. Le premier chapitre fait un état de l’art des deux classes de composés magnétiques utilisées dans ce travail : les molécule-aimants et les systèmes à transfert d’électrons. Une brève description des systèmes magnétiques hybrides présents dans la littérature est ensuite présentée dans le but d’illustrer les motivations qui ont conduit à ce travail. Le chapitre II décrit la fonctionnalisation des molécule-aimants de type [Mn12] dans le but d’obtenir des systèmes cristaux liquides hybrides. Deux approches ont été étudiées : (a) la fonctionnalisation des ligands périphériques avec des groupements fortement lipophiles (longues chaines alkyle) ou (b) le greffage de promoteurs mésogènes par l’intermédiaire d’espaceurs aliphatiques flexibles. Les chapitres III à V présentent les études sur des carrés moléculaires à ponts cyanure {Fe2Co2} qui montrent un transfert d’électron thermo- et photo-induit. Le chapitre III discute de la possibilité de moduler le processus de transfert d’électron de ces carrés moléculaires via le changement du contre anion. La fonctionnalisation du carré moléculaire {Fe2Co2} avec de chaines aliphatiques et son impact induit sur les propriétés physiques à l’état solide et en solutions sont décrits dans le chapitre IV. Le chapitre V discute de l’effet de la fonctionnalisation avec des groupements fortement électrodonneurs, tels que les groupements méthoxy, sur le processus de transfert d’électron des carrés moléculaires {Fe2Co2}. / The work presented in this thesis was focused on the design and investigation of novel hybrid materials via ligand functionalization of the single-molecule magnets (SMMs) and electron transfer complexes. Chapter I contains general information about these two classes of the magnetic systems. In order to illustrate the motivation behind our work, a brief review on previously reported soft hybrid magnetic systems, is presented. Chapter II is dedicated to the functionalization of [Mn12]-based SMMs towards hybrid liquid crystalline systems via two different approaches: (a) the functionalization of peripheral ligands with strongly lipophilic groups (long alkyl chains), or (b) the grafting of mesogenic promoters through flexible aliphatic spacers. Chapters III – V are focused on cyanido-bridged molecular {Fe2Co2} squares that exhibit thermally or photo-induced electron transfer. Thus, in Chapter III, the possibility to modulate the electron transfer properties in {Fe2Co2} molecular squares via the use of different counter-anion is discussed. The functionalization with long aliphatic chains and its influence over the properties of {Fe2Co2} molecular squares in solid state and solutions are discussed in Chapter IV. Finally, the effect of the ligand functionalization with strongly electron density donating groups (methoxy) over the electron transfer properties of {Fe2Co2} molecular squares is investigated in Chapter V.

Cette thèse présente une étude de films monomoléculaires d'acides gras à l'interface eau-air, principalement par microscopie à l'angle de Brewster. Cette technique permet l'observation directe des coexistences de phases lors de transitions de phases du premier ordre; de plus elle est sensible à l'anisotropie optique des films. La première partie contient une étude du diagramme de phase des acides gras, qui comporte des mésophases analogues aux phases de cristaux liquides smectiques. Nous avons montré que lors des transitions de phases entre phases denses, la texture (l'arrangement moléculaire)des phases est réversible et nous avons obtenu des informations sur l'ordre des transitions. Nous avons aussi mis en évidence, dans deux phases constituées de molécules verticales, une très faible anisotropie optique due à la forme rectangulaire du réseau moléculaire. Nous avons ensuite étudié une film d'acide myristique adsorbé à la surface d'une solution aqueuse d'acide myristique. Nous avons observé des domaines d'une mésophase "inclinée" contenant des lignes de défauts d'orientationmoléculaire présentant des fluctuations thermiques. La mesure de leur amplitude a permis de déterminer la tension de ces lignes. Nous nous sommes aussi intéressés aux constantes élastiques qui gouvernent la forme et la texture à l'équilibre des domaines de mésophase. Nous avons d'une part déterminé la tension de ligne de l'interface entre une phase liquide et une mésophase "inclinée" en étudiant la forme des domaines. Celle-ci résulte de l'équilibre entre la tension de ligne, qui favorise des domaines circulaires, et les interactions répulsives à longue portée entre dipoles moléculaires, qui forment les domaines. Des mesures de potentiel de surface ont permis de calculer l'intensité des forces dipolaires. d'autre part, la texture d'autre domaines de cette mésophaseinclinée nous a renseigné sur la valeur du rapport entre l'élasticité de courbure de la direction moléculaire et l'anisotropie de la tension de ligne.

<p>Designing an application specific integrated circuit (ASIC) must be starting with careful preparations, otherwise the chip will not be as good as possible. The theoretical studies must cover everything from the chip circuits to the application structure. In mobile applications there is extremely important that the current consumption becomes minimized because the battery power is limited. The power reductions studies must include the most power costing circuits on the chip. When the whole circuit or segments of the circuit is not in use, they must switch fast and simple into another mode that consume nearly none power. This mode is called sleep-mode. If the sleep-mode has very low leakage currents, the lifetime of the application will dramatically increase. </p><p>This report studies the most power costing circuits in smartcard application ASIC. The chip should be used to control a LCD display on the smartcard. The circuits that have been investigated are level shifters, charge pumps and LCD drivers, also sleep-mode configuration possibilities have been investigated. Other small preparing work is also included in the thesis.</p>

<p>The aim of this thesis was to investigate amphiphilic molecules in aqueous solution. The work was divided into two parts. In the first part the effects of different counterions on phase behavior was investigated, while the second part concerns the 1-monooleoyl-rac-glycerol (MO)/n-octyl-β-D-glucoside (OG)/2H2O-system. </p><p>The effects of mixing monovalent and divalent counterions were studied for two surfactant systems, sodium/calcium octyl sulfate, and piperidine/piperazine octanesulfonate. It was found that mixing monovalent and divalent counterions resulted in a large decrease in cmc already at very low fractions of the divalent counterion. Moreover, the degree of counterion binding for piperidine in the piperidine/piperazine octanesulfonate system was much higher than predicted, probably due to the larger hydrophobic moiety of piperidine.</p><p>The effects of hydrophobic counterions were studied for eight alkylpyridinium octanesulfonates (APOS). The results were discussed in terms of packing constraints. The anomalous behavior of the 2H2O quadrupolar splittings in the lamellar phases was explained by the presence of two or more binding sites at the lamellae surface. </p><p>The MO/OG/water system was studied in general and the MO-rich cubic phases in particular. When mixing MO and OG it was found that OG-rich structures (micelles, hexagonal and cubic phase of space group Ia3d) could solubilize quite large amounts of MO, while the MO-rich cubic structures where considerable less tolerant towards the addition of OG. The micelles in the OG-rich L1 phase were found to remain rather small and discrete in the larger part of the L1 phase area, but at low water concentration and high MO content a bicontinuous structure was indicated. Only small fractions of OG was necessary to convert the MO-rich cubic Pn3m structure to an Ia3d structure, and upon further addition of OG a lamellar (La) phase formed. Since the larger part of the phase diagram contains a lamellar structure (present either as a single La phase or as a dispersion of lamellar particles together with other phases), the conclusion was that introducing OG in the MO structures, forces the MO bilayer to become more flat. Upon heating the cubic phases, structures with more negative curvature were formed. The transformation between the cubic structures required very little energy, and this resulted in the appearance of additional peaks in the diffractograms.</p>

<p>Laser beam control is important in many applications. Phase modulating spatial light modulators (SLMs) can be used to electronically alter the phase distribution of an optical wave-front and thus change the direction and shape of a laser beam. Physical constraints set limitations to the SLM and an ideal phase distribution can usually not be realised. In order to understand how such components can be used for non-mechanical beam control three nematic liquid crystal (NLC) SLMs have been thoroughly characterised and modelled.</p><p>The pixel structure and phase quantisation give a discrepancy between ideal and realised phase distributions. The impact on beam steering capability was examined by measurements and simulations of the intensity distribution in the far-field.</p><p>In two of the studied SLMs the pixel period was shorter than the thickness of the LC layer giving the optical phase shift. This results in a so-called “fringing field”, which was shown to degrade the phase modulation and couple light between polarisation modes. The deformation of the LC was simulated and a finite-difference time-domain (FDTD) algorithm was used to calculate how polarised light propagates through the optically anisotropic SLM.</p><p>Non-mechanical beam steering and tracking in an optical free-space communication link were demonstrated. Continual optimisation of the steering angle was achieved by feedback from a video camera.</p><p>The optical properties of the SLM in the time period right after a voltage update were studied. It was shown how light is redistributed between orders during the switching from one blazed grating to another. By appropriate choice of the blazed gratings the effects on the diffraction efficiency can be minimised.</p><p>The detailed knowledge of the SLM structure and its response to electronic control makes it possible to predict and optimise the device performance in future systems.</p>

<p>The interactions between anionic, crosslinked gels and cationic surfactants have been investigated. When exposed to oppositely charged surfactant, the gel collapses into a dense complex of polyion and micelles. During deswelling, the gel phase separates into a micelle-rich, collapsed surface phase, and a swollen, micelle-free core, both still part of the same network. As more surfactant is absorbed, the surface phase grows at the expense of the core, until the entire gel has collapsed. Polyacrylate (PA) gels with dodecyl- (C₁₂TAB), and cetyltrimethylammonium bromide (C₁₆TAB), as well as hyaluronate gels with cetylpyridinium chloride, have been studied. </p><p>Kinetic experiments have been performed on macro- as well as microgels, using micromanipulator assisted light microscopy for the latter. A surfactant diffusion controlled deswelling model has been employed to describe the deswelling. The deswelling kinetics of PA microgels have been shown to be controlled by surfactant diffusion through the stagnant layer surrounding the gel, as the surface phase is relatively thin for the major part of the deswelling. For macroscopic PA gels the surface phase is thicker, and the kinetics with C₁₂TAB were therefore also influenced by diffusion through the surface phase, while for C₁₆TAB they were dominated by it. </p><p>Relevant parameters have also been determined using equilibrium experiments. An irregular, balloon-forming deswelling pattern, mainly found for macrogels, as well as unexpectedly long lag times and slow deswelling for microgels, are reported and discussed. </p><p>The microstructure of fully collapsed PA/C₁₂TAB complexes has been studied using small-angle X-ray scattering. A cubic <i>Pm3n</i> structure was found at low salt concentration, which melted into a disordered micellar phase as the salt concentration was increased. Further increasing the salt concentration dissolved the micelles, resulting in no ordering.</p>

Contribution à l’étude de la réflectance et du confinement des modes dans les systèmes optiques stratifiés Résumé : Ce travail prolonge les études du changement de réflectivité des systèmes optiques stratifiés sous des contraintes mécanique et électrique. D’abord, nous quantifions le déplacement de la bande interdite photonique suite à une modification de l’angle d’incidence. Il en dérive une technologie bio-inspirée. Ensuite, c’est un champ électrique externe qui contrôle les propriétés de réflexion et de polarisation d’une multicouche construite à partir de cristaux liquides. Enfin, nous distinguons deux manières de confiner l’énergie électromagnétique. Ce travail s’attache à comprendre la nature des modes qui se propagent à la surface des milieux stratifiés. Par ailleurs, il montre que l’association de matériau gauche et de matériau droit pour former un guide d’onde permet de réduire la vitesse de la lumière de plusieurs ordres de grandeur. Contribution to the study of the reflectance and the mode confinement in optical stratified systems Abstract : This work extends the studies of change in reflectance in optical stratified systems under mechanical and electrical constraints. In the first part, we quantify the shift of the photonic bandgap following, a modification in the angle of incidence. We define the tools for the design of bio-inspired Bragg mirrors. In the second part, we adjust the reflection properties of a multilayer stack made of liquid crystals with an external electric field. Furthermore, we examine two distinct ways of producing light confinement. First, we contribute to the understanding of the nature of electromagnetic modes propagating at the surface of stratified media. Second, we show that a waveguide made of left- and right-handed materials can reduce the speed of light by several orders of magnitudes.

The aim of this thesis was to investigate amphiphilic molecules in aqueous solution. The work was divided into two parts. In the first part the effects of different counterions on phase behavior was investigated, while the second part concerns the 1-monooleoyl-rac-glycerol (MO)/n-octyl-β-D-glucoside (OG)/2H2O-system. The effects of mixing monovalent and divalent counterions were studied for two surfactant systems, sodium/calcium octyl sulfate, and piperidine/piperazine octanesulfonate. It was found that mixing monovalent and divalent counterions resulted in a large decrease in cmc already at very low fractions of the divalent counterion. Moreover, the degree of counterion binding for piperidine in the piperidine/piperazine octanesulfonate system was much higher than predicted, probably due to the larger hydrophobic moiety of piperidine. The effects of hydrophobic counterions were studied for eight alkylpyridinium octanesulfonates (APOS). The results were discussed in terms of packing constraints. The anomalous behavior of the 2H2O quadrupolar splittings in the lamellar phases was explained by the presence of two or more binding sites at the lamellae surface. The MO/OG/water system was studied in general and the MO-rich cubic phases in particular. When mixing MO and OG it was found that OG-rich structures (micelles, hexagonal and cubic phase of space group Ia3d) could solubilize quite large amounts of MO, while the MO-rich cubic structures where considerable less tolerant towards the addition of OG. The micelles in the OG-rich L1 phase were found to remain rather small and discrete in the larger part of the L1 phase area, but at low water concentration and high MO content a bicontinuous structure was indicated. Only small fractions of OG was necessary to convert the MO-rich cubic Pn3m structure to an Ia3d structure, and upon further addition of OG a lamellar (La) phase formed. Since the larger part of the phase diagram contains a lamellar structure (present either as a single La phase or as a dispersion of lamellar particles together with other phases), the conclusion was that introducing OG in the MO structures, forces the MO bilayer to become more flat. Upon heating the cubic phases, structures with more negative curvature were formed. The transformation between the cubic structures required very little energy, and this resulted in the appearance of additional peaks in the diffractograms.

Laser beam control is important in many applications. Phase modulating spatial light modulators (SLMs) can be used to electronically alter the phase distribution of an optical wave-front and thus change the direction and shape of a laser beam. Physical constraints set limitations to the SLM and an ideal phase distribution can usually not be realised. In order to understand how such components can be used for non-mechanical beam control three nematic liquid crystal (NLC) SLMs have been thoroughly characterised and modelled. The pixel structure and phase quantisation give a discrepancy between ideal and realised phase distributions. The impact on beam steering capability was examined by measurements and simulations of the intensity distribution in the far-field. In two of the studied SLMs the pixel period was shorter than the thickness of the LC layer giving the optical phase shift. This results in a so-called “fringing field”, which was shown to degrade the phase modulation and couple light between polarisation modes. The deformation of the LC was simulated and a finite-difference time-domain (FDTD) algorithm was used to calculate how polarised light propagates through the optically anisotropic SLM. Non-mechanical beam steering and tracking in an optical free-space communication link were demonstrated. Continual optimisation of the steering angle was achieved by feedback from a video camera. The optical properties of the SLM in the time period right after a voltage update were studied. It was shown how light is redistributed between orders during the switching from one blazed grating to another. By appropriate choice of the blazed gratings the effects on the diffraction efficiency can be minimised. The detailed knowledge of the SLM structure and its response to electronic control makes it possible to predict and optimise the device performance in future systems.