A waterflood has been used as a secondary recovery process to maintain the reservoir pressure and displace the oil towards the producer. However, the existence of high-permeability zones (thief zones) can cause early water breakthrough and excessive water production, thus, leaving a significant amount of oil bypassed in heterogeneous reservoirs. In this work, thermally active (Bright Water®) and pH-sensitive polymers have been proposed as an in-depth conformance tool with detailed simulation studies. Thermally active polymers are triggered by temperature change, whereas pH-sensitive polymers are triggered by pH change. Upon activation, polymers provide high resistance to subsequent fluid flow and divert the flow into adjacent unswept zones. As a result, this leads to improved sweep efficiency, low oil-water-ratio, and incremental oil recovery. The modeling of a pH-sensitive polymer was based on the principles of the microgel modeling procedure developed by Huh et al. (2005). In addition, a modified model was developed to calculate equilibrium swelling ratio explicitly in terms of pH and ionic strength of solution instead of using a root-finding algorithm. Thermal active polymers were modeled in terms of gelation reaction, gel viscosity, gel adsorption, and permeability reduction factor. Thermally active and pH-sensitive polymers were coupled with UTGEL reservoir simulator in an attempt to assess applicability of these gels as a conformance tool. Sensitivity analysis studies were conducted through 3D synthetic models to investigate technical feasibility of thermally active and pH-sensitive polymers as an in-depth conformance tool. Results indicated that incremental oil recovery and conformance control depend on the polymer concentration, slug size, permeability contrast between matrix and thief zone, vertical to horizontal permeability ratio (kv/kh), treatment location, oil-to-water viscosity ratio, and adsorption level, among others. It is concluded in this study that the permeability contrast between matrix and thief zones appears to be one of the most important parameters that impacts treatment performance. Therefore, a high permeability contrast is a prerequisite to achieve technically and economically successful treatment. / text

Step-growth polymerization provided an effective method for the preparation of several high performance polymers. Step-growth polymerization was used for syntheses of poly(siloxane imides), polyesters, poly(triazole esters), poly(triazole ether esters), and epoxy networks. Each of these polymeric systems exhibited novel structures, and either photoreactive capabilities, or high performance properties. There is an increasing trend towards the development of photoactive adhesives. In particular these polymers are often used in flip bonding, lithography, stimuli responsive polymers, drug delivery, and reversible adhesives. The ability to tailor polymer properties carefully with exposure to light allows for very unique stimuli responsive properties for many applications. This dissertation primarily investigates photoreactive polymers for reversible adhesion for use in the fabrication of microelectronic devices. In particular cyclobutane diimide functionality within polyimides and poly(siloxane imides) and o-nitro benzyl ester functionality within polyesters acted effectively as chromophores to this end. Thermal solution imidization allowed for the effective synthesis of polyimides and poly(siloxane imides). 1,2,3,4-Cyclobutane tetracarboxylic dianhydride acted as the chromophore within the polymer backbone. The polyimides obtained exhibited dispersibility only in dipolar, aprotic, high boiling solvents such as DMAc or NMP. The obtained poly(siloxane imides) demonstrated enhanced dispersibility in lower boiling organic solvents such as THF and CHCl₃. Dynamic mechanical analysis and tensile testing effectively measure the mechanical properties of the photoactive poly(siloxane imides) and confirmed elastomeric properties. Atomic force microscopy confirmed microphase separation of the photoactive poly(siloxane imides). ¹H NMR spectroscopy confirmed formation of maleimide peaks upon exposure to narrow band UV light with a wavelength of 254 nm. This suggested photo-cleavage of the cyclobutane diimide units within the polymer backbone. Melt transesterification offered a facile method for the synthesis of o-nitro benzyl ester-containing polyesters. ¹H NMR spectroscopy confirmed the structures of the photoactive polyesters and size exclusion chromatography confirmed reasonable molecular weights and polydispersities of the obtained samples. ¹H NMR spectroscopy also demonstrated a decrease in the integration of the resonance corresponding to the o-nitro benzyl ester functionality relative to the photo-stable m-nitro benzyl ester functionality upon exposure to high-intensity UV light, suggesting photo-degradation of the adhesive. ASTM wedge testing verified a decrease in fracture energy of the adhesive upon UV exposure, comparable to the decrease in fracture energy of a commercial hot-melt adhesive upon an increase in temperature. Click chemistry was used to synthesize polyesters and segmented block copolyesters. Triazole-containing homopolyesters exhibited a marked increase (~40 °C) in Tg, relative to structurally analogous classical polyesters synthesized in the melt. However, the triazole-containing homopolyesters exhibited insignificant dispersibility in many organic solvents and melt-pressed films exhibited poor flexibility. Incorporation of azide-functionalized poly(propylene glycol) difunctional oligomers in the synthesis of triazole-containing polyesters resulted in segmented block copolyesters which exhibited enhanced dispersibility and film robustness relative to the triazole-containing homopolyesters. The segmented triazole-containing polyesters all demonstrated a soft segment Tg near -62 °C, indicating microphase separation. Dynamic mechanical analysis confirmed the presence of a rubbery plateau, with increasing plateau moduli as a function of hard segment content, as well as increasing flow temperatures as a function of hard segment content. Tensile testing revealed increasing tensile strength as a function of hard segment, approaching 10 MPa for the 50 wt % HS sample. Atomic force microscopy confirmed the presence of microphase separated domains, as well as semicrystalline domains. These results indicated the effectiveness of click chemistry towards the synthesis of polyesters and segmented block copolyesters. Click chemistry was also used for the synthesis of photoactive polyesters and segmented block polyesters. The preparation of 2-nitro-p-xylylene glycol bispropiolate allowed for the synthesis of triazole-containing polyesters, which exhibited poor dispersibility and flexibility of melt-pressed films. The synthesis of segmented photoactive polyesters afforded photoactive polyesters with improved dispersibility and film robustness. ¹H NMR spectroscopy confirmed the photodegradation of the o-nitro benzyl functional groups within the triazole-containing polyesters, which indicated the potential utility of these polyesters for reversible adhesion. Synthesis of the glycidyl ether of 2,2,4,4-tetramethyl-1,3-cyclobutane diol (CBDOGE) allowed for the subsequent preparation of epoxy networks which did not contain bisphenol-A or bisphenol-A derivatives. Preparation of analogous epoxy networks from the glycidyl ether of bisphenol-A (BPA-GE) provided a method for control experiments. Tensile testing demonstrated that, dependent on network Tg, the epoxy networks prepared from CBDOGE exhibited similar Young's moduli and tensile strain at break as epoxy networks prepared from BPAGE. Dynamic mechanical analysis demonstrated similar glassy moduli for the epoxy networks, regardless of the glycidyl ether utilized. Tg and rubbery plateau moduli varied as a function of diamine molecular weight. Melt rheology demonstrated a gel time of 150 minutes for the preparation of epoxy networks from CBDO-GE and 78 minutes for the preparation of epoxy networks from BPA-GE, with the difference attributed to increased sterics surrounding CBDO-GE. These results indicated the suitability of CBDO-GE as a replacement for BPA-GE in many applications. / Ph. D.

Aufgrund der zunehmenden technischen Ansprüche der Gesellschaft sind sich aktiv bewegende Polymere in den Mittelpunkt aktueller Forschung gerückt. Diese spielen bei Anwen-dungen im Bereich von künstlichen Muskeln und Implantaten für die minimal invasive Chirurgie eine wichtige Rolle. Vor allem Formänderungs- und Formgedächtnispolymere stehen dabei im wissenschaftlichen Fokus. Während die kontaktlose Deformation einer permanenten Form in eine temporäre metastabile Form, charakteristisch für Formände-rungspolymere ist, kann bei Formgedächtnis-Materialien die temporäre Form, aufgrund der Ausbildung reversibler, temporärer Netzpunkte, fixiert werden. Ein Polymermaterial, das eine Kombination beider Funktionen aufweist würde zu einem Material führen welches kontaktlos in eine temporäre Form deformiert und in dieser fixiert werden kann. Zusätzlich würde aufgrund der kontaktlosen Deformation die Reversibilität dieser Funktion gewähr-leistet sein. Ein solches Material ist bislang noch nicht beschrieben worden. In dieser Arbeit wird untersucht, ob durch die Kopplung zweier separat schaltbarer, be-kannter Funktionen eine neue schaltbare Funktion erzielt werden kann. Daher wurden multi-stimuli sensitive Materialien entwickelt die eine Kopplung des Formänderungs- und des Formgedächtniseffektes aufweisen. Dazu wurden zwei Konzepte entwickelt, die sich hinsichtlich der Reihenfolge der verwendeten Stimuli unterscheiden. Im ersten Konzept wurden flüssigkristalline Elastomere basie-rend auf Azobenzenderivaten aufgebaut und hinsichtlich der Kombination des licht-induzierten Formänderungseffektes mit dem thermisch-induzierten Formgedächtniseffekt untersucht. Diese orientierten Netzwerke weisen oberhalb der Glasübergangstemperatur (Tg) eine kontaktlose Verformung (Biegung) durch Bestrahlung mit UV-Licht des geeigneten Wellenlängenbereichs auf, wodurch eine temporäre Form erhalten wurde. Hierbei spielt der Vernetzungsgrad eine entscheidende Rolle bezüglich der Ausprägung dieser Biegung. Eine fixierte, temporäre Form konnte durch gleichzeitiges Abkühlen des Materials unterhalb von Tg während der Bestrahlung mit UV-Licht erhalten werden. Nach erneutem Aufheizen über Tg konnte die Originalform wiederhergestellt werden. Dieser Vorgang konnte reversibel durchgeführt werden. Damit wurde gezeigt, dass eine neue schaltbare Funktion erzielt wurde, die auf der Kopplung des lichtinduzierten Formänderungs- mit dem thermisch-induzierten Formgedächtniseffekt basiert. Die Abstimmung der einzelnen Funktion wird in diesem Konzept über die Morphologie des Systems gewährleistet. Diese neue Funktion ermöglicht eine kontaktlose Deformation des Materials in eine temporäre Form, welche fixiert werden kann. Im zweiten Konzept wurde eine Kopplung des thermisch induzierten Formänderungs- mit dem licht-induzierten Formgedächtniseffekt angestrebt. Um dies zu realisieren wurden nematisch, flüssigkristalline Hauptkettenelastomere (NMC-LCE) entwickelt, die eine nied-rige Übergangstemperatur der nematischen in die isotrope Phase (TNI), als auch einen aus-geprägten thermisch induzierten Formänderungseffekt aufweisen. Zusätzlich wurde eine photosensitive Schicht aufgebaut, die Cinnamylidenessigsäuregruppen in der Seitenkette eines Polysiloxanrückgrates aufweist. Die Reversibilität der photoinduzierten [2+2]-Cycloaddition konnte für dieses photosensitive Polymer beobachtet werden, wodurch die-ses Polymersystem in der Lage ist reversible temporäre Netzpunkte, aufgrund der Bestrah-lung mit UV-Licht, auszubilden. Die kovalente Anbindung der photosensitiven Schicht an die Oberfläche des flüssigkristallinen Kerns wurde erfolgreich durchgeführt, wodurch ein Multi-Komponenten-System aufgebaut wurde. Die Kombination des thermisch-induzierten Formänderungs- mit dem licht-induzierten Formgedächtniseffektes wurde anhand dieses Systems untersucht. Während die Einzelkomponenten die erforderliche Funktion zeigten, ist hier noch Arbeit in der Abstimmung beider Strukturen zu leisten. Insbesondere die Variation der Schichtdicken beider Komponenten steht im Fokus zukünftiger Arbeiten. In dieser Arbeit wurde durch die Kopplung von zwei separat schaltbaren, bekannten Funktionen eine neue schaltbare Funktion erzielt. Dies setzt voraus, dass die Einzelkomponenten hinsichtlich einer Funktion schaltbar sind und in einem Material integriert werden können. Des Weiteren müssen die beiden Funktionen mit unterschiedlichen Stimuli geschaltet werden. Ein wichtiger Schritt bei der Kopplung der Funktionen, ist die Abstimmung der beiden Komponenten. Dies kann über die Variation der Morphologie oder der Struktur erzielt werden. Anhand der Vielzahl der vorhandenen stimuli-sensitiven Materialien sind verschiedene Kopplungsmöglichkeiten vorhanden. Demnach wird erwartet, dass auf diesem Gebiet weitere neue Funktionen erzielt werden können. / Actively moving polymers are high scientific significance due to their ability to move actively in response to an external stimulus. Most notably shape-change and shape-memory polymers are in the focus of current research. Shape-changing polymers exhibit a non-contact deformation from a permanent into a temporary shape, which is just stable as long the material is exposed to an external stimulus. In contrast shape-memory polymers are capable of a fixed temporary shape due to the formation of additional temporary netpoints, while the deformation is proceed by applying mechanical stress. A polymeric material, which combines both functions would result into a material that possesses the advantages of the shape-change, as well as the shape-memory effect. In this work, the coupling of two known functions is investigated which results into a new switchable function. Therefore, two different concepts were developed requiring different material structures. For the first concept monodomain, smectic liquid-crystalline elastomers (LCE) containing azobenzene moieties were prepared and the coupling of the light-induced shape-change with the thermally-induced shape-memory effect was investigated. These oriented LCE's exhibit a non-contact deformation into a temporary shape, above the glass transition temperature (Tg), due to the irradiation with UV-light. The temporary shape could be fixed by cooling the material below Tg, while the irradiation with light was kept constant. The permanent shape could be recovered by additional heating above Tg. This process could be repeated several times. Therefore, a new switchable function was developed, which based on the coupling of the light-induced shape-change with the thermally induced shape-memory effect. The second concept required a multi-component system and the coupling of the thermally-induced shape-memory withe the light-induced shape-change effect was investigated. The multi component system consists of a LCE-core and a photosensitive layer. Nematic, main-chain elastomers were prepared, which possess of low transition temperatures and high actuation performances. The photosensitive layer consists of cinnamylidene acetic moieties, that were attached to a siloxane backbone, while the photoreversibility of the light-induced [2+2]-cycloaddition was shown. Furthermore, the photosensitive layer was covalently attached to the surface of the LCE-core. While both components showed their functionality, the coupling of the thermally-induced shape-change with the light-induced shape-memory effect was not successful up to now. The Adjustment of both components on each other has to be improved. Mainly the variation of the layer thickness of both structural components should be in the focus of future work.

L’utilisation de systèmes robotiques pour la navigation dans des zones confinées pose des défis intéressants sur les thèmes de conception, de modélisation et de commande, particulièrement complexes pour les applications médicales. Dans ce contexte, nous introduisons un nouveau concept de robots continus, fortement prometteurs pour des applications biomédicales, dont la forme complexe, la dextérité et la capacité de miniaturisation constituent des avantages majeurs pour la navigation intra corporelle. Parmi cette classe, les robots à tubes concentriques (RTC), qui constituent notre point de départ, sont améliorés grâce à un actionnement embarqué innovant. Nos travaux s’articulent autour de deux thématiques aux frontières de l’état de l’art. D’une part, nous avons proposé une modélisation générique et conduit une analyse cinématique approfondie de robots continus basés sur l’architecture des RTC standards et ceux avec changement de courbure de leurs tubes dans deux variantes : courbures unidirectionnelle et bidirectionnelle. D’autre part, leur commande cartésienne en pose complète est introduite avec une validation expérimentale sur un prototype développé de RTC standard, ainsi que les simulations numériques d’une loi de commande comprenant la gestion de la redondance des RTC à changement de courbure. D’autre part, nous avons effectué la synthèse, la caractérisation et la mise en œuvre de micro-actionneurs souples basés sur les polymères électro-actifs (PEA), intégrés pour la première fois dans un robot continu.Ainsi, l’asservissement visuel d’un prototype de robot télescopique souple est proposé avec des précisions atteignant 0.21 mm sur différentes trajectoires. / Major challenges need to be risen in order to perform navigation in confined spaces with robotic systems in terms of design, modeling, and control, particularly for biomedical applications. Indeed,the complex shape, dexterity, and miniaturization ability of continuum robots can help solving intracorporeal navigation problems. Within this class, we introduce a novel concept in order to augment the concentric tube robots (CTR) with embedded actuation. Our works hinge on two majorcutting-edge thematics. On the one hand, we address modeling and kinematics analysis of standard CTR as well as variable curvature CTR with their two varieties : single and double bending directions.Furthermore, we perform the experimental validation of Cartesian control of a CTR prototype, anda task hierarchy based control law for redundancy resolution of CTR with variable curvatures. Onthe other hand, we develop the synthesis, the characterization, and the integration of soft microactuatorsbased on electro-active polymers (EAP) for the first time in a continuum robot. Thus, thevisual servoing of a telescopic soft robot is performed with precisions down to 0.21 mm following different trajectories.

<p> In an era of advancing printed electronics, solution-processable organic semiconductors continue to make significant strides in electronic and optoelectronic applications. Electrochromic (EC) technology, which encompass reversible optical modulation under electrochemical biasing, has progressed rapidly over the past half-century and developed into niche commercial-scale devices for auto-tinting glasses as well as low-power, non-emissive displays. To utilize the advantages of organic electrochromic materials in next-generation devices, it is imperative to understand their fundamental material properties, interactions with other device components, and the underlying electrochemistry that governs the overall optical and electrochemical response of the complete electrochromic device. This dissertation presents a discussion on the synergistic role of organic electrochromes, charge-balancing layers and electrolytes in determining two key performance metrics, namely the optical contrast and operational stability, of an electrochromic device (ECD). The absorption features of colored-to-transmissive switching conjugated polymers have been investigated by exploring material design strategies in conjunction with analytical approaches to optimize and enhance the optical contrast. In parallel, transmissive redox-active radical polymer counter electrodes have been developed as compatible charge-balancing layers and integrated into devices by pairing with electrochromic polymers (ECPs) to achieve stable and high-contrast optical modulation. Electrochemical activity of both conjugated and radical polymer electrodes in different ionic and solvent environments have been further examined to understand material-electrolyte interactions governing mixed ionic-electronic conduction. Finally, a small molecular approach to realizing transparent-to-colored electrochromism is discussed, where distinct substituent-induced degradation pathways of conjugated radical cations were revealed. Overall, this research aims to assist future development of robust, ultra-high contrast organic electrochromic platforms.  </p>