Supramolecular polymers represent a family of polymeric materials that are held together with dynamic, noncovalent interactions. In contrast to conventional functional polymers that usually have high melt-viscosity due to their covalent nature and chain entanglement, supramolecular polymers combine excellent physical properties with low melt-viscosity, allowing for less energy-intensive processability and recyclability. Dynamic bonding with multiple binding sites, such as multiple hydrogen bonding or multiple ionic bonding, exhibits much stronger binding strength compared to the counterparts containing only a single binding site, thereby allowing for enhanced mechanical integrity to the polymers and facilitate self-assembly. This dissertation focuses on the design of novel supramolecular polymers building from the doubly-charged or quadruple hydrogen bonding (QHB) scaffolds utilizing chain-growth polymerization or step-growth polymerization, as well as elucidate the structure-property-morphology relationships of the polymers. A 2-step nucleophilic substitution reaction afforded a series of 1,4-diazabicyclo[2.2.2]octane (DABCO)-based styrenic monomers with two pairs of charged groups. An optimized 2-step reversible-addition-fragmentation chain-transfer (RAFT) polymerization synthesized ABA triblock thermoplastic elastomers (TPEs) with a low Tg poly (n-butyl acrylate) central block and a high Tg external charged blocks. Strong ionic interactions between doubly-charged units drove molecular self-assembly to form densely packed, hierarchical microstructures, which contributed to a robust, crosslinked physical network that allows the polymer to retain thermomechanical integrity until degradation. High-resolution single-crystal X-ray diffraction (SCXRD) coupled with powder X-ray diffraction (PXRD) further disclosed a detailed 3-D structural information of molecular arrangement and ion distribution within the charged phase through comparing DABCO-salt monomer single-crystal structure and the corresponding homopolymer XRD pattern. It was found that the physical properties of the DABCO-salt copolymers not only relied on their charge content and architectures but also dependent on their electrostatically-bonded counterions. The size and structure of the counterion determined the strength of dipole-dipole interaction, which significantly impact on thermal property, (thermo)mechanical performance, water affinity, and microstructure. A cytosine-functionalized monomer, cytosine acrylate (CyA), allowed the synthesis of acrylic ABA triblock TPEs with pendant nucleobase moieties in the external blocks and a low Tg central polymer matrix through RAFT polymerization. Post-functionalization of cytosine (Cyt) bidentate hydrogen bonding sites with alkyl isocyanate, allowed the formation of ureido-cytosine (UCyt) groups in the external block that were readily dimerized through QHB interactions. The UCyt units in the external block enhanced mechanical strength and induced stronger phase-separation of the block copolymers compared to the corresponding Cyt-containing TPE analogs. Facile conventional free-radical polymerization using CyA and subsequent post-functionalization enabled accessibility to random copolymers containing pendant UCyt QHB moieties in the soft polymer matrix. The synergy of the flexible polymer matrix and the dynamic character of QHB groups contributed to the ultra-high elasticity of the polymer and rapid self-healing properties. QHB interactions enabled efficient mechanical recovery upon deformation by facilitating elastic chain retraction to regenerate the original physical network. Finally, one-pot step-growth polymerization through chain extending a novel bis-Cyt monomer and a commercially available polyether diamine using a di-isocyanate extender afforded segmented polyurea series for extrusion additive manufacturing. The molecular design of the polyureas featured soft segments containing flexible polyether chain and a relatively weak urea hydrogen bonding sites in the soft segment and rigid UCyt hydrogen bonding groups in the hard segment. The reversible characteristics of QHB enabled low viscosity at the processing temperature while providing mechanical integrity after processing and reinforced bonding between the interlayers, which contributed to the remarkable strength, elasticity, toughness, and interlayer adhesion of the printed parts. / Doctor of Philosophy / This dissertation focuses on designing supramolecular thermoplastic elastomers containing strong noncovalent interactions, i.e., quadruple hydrogen bonds or double ionic bonds. Inspired from noncovalent interactions in our mother nature, a series of bio-inspired monomers functionalized with nucleobase or ionic units were synthesized through scalable reactions with minimal purification steps. Polymerization of the functional monomers through step-growth or chain-growth polymerization techniques affords a variety of supramolecular thermoplastic elastomers with well-defined structures and architectures. These thermoplastic elastomers comprise soft and hard constituents; the former contains low glass transition polymer chains that provide elasticity while the latter contains strong noncovalent units to impart mechanical strength. Varying the soft/hard component ratios enables polymers with tunable physical properties to address different needs. Systematic characterizations of these supramolecular polymers revealed their distinct properties from the polymers containing the covalent or weak noncovalent interactions and facilitate molecular-level understanding of the polymers. Generally, incorporating strong noncovalent interactions increases the temperature for polymer segmental motion and extends thermomechanical plateau windows. Additionally, the strong association strength of those non-covalent interactions promotes microphase separation and self-assembly, contributing to a high degree of structural ordering of the polymers. Moreover, the dynamic characteristics of the noncovalent interactions offer the polymers with reversible properties, which not only enables melt-processability and recyclability of the polymer but also contributes to a series of smart properties, including self-healing, shape-memory, and recoverability. Thus, the molecular design using supramolecular chemistry provides promising avenues to developing functional materials with enhanced mechanical properties, processability, and stimuli-responsiveness for emerging applications.

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The aim of the present work was to screen the main methods for the synthesis of conjugated polymers for their suitability in the preparation of conductive polymer brushes. The main focus was put on the grafting of intrinsically soluble substituted regioregular polyalkylthiophenes because of their excellent optoelectronic properties. The resulting polymer films were characterized and their optoelectrical properties studied. For the first time, a synthesis of conductive polymer brushes on solid substrates using “grafting-from” method was performed. The most important, from my opinion, finding of this work is that regioregular head-to-tail poly-3-alkylthiophenes – benchmark materials for organic electronics - can be now selectively grafted from appropriately-terminated surfaces to produce polymer brushes of otherwise soluble polymers - the architecture earlier accessible only in the case of non-conductive polymers. In particular, we developed a new method to grow P3ATs via Kumada Catalyst Transfer Polymerization (KCTP) of 2-bromo-5-chloromagnesio-3-alkylthiophene. Exposure of the initiator layers to monomer solutions leads to selective chain-growth polycondensation of the monomers from the surface, resulting into P3AT brushes in a very economical way. The grafting process was investigated in detail and the structure of the resulting composite films was elucidated using several methods. The obtained data suggests that the grafting process occurs not only at the poly(4-bromstyrene) (PS-Br)/polymerization solution interface, but also deeply inside the swollen PS-Br films, penetrable for the catalyst and for the monomer The grafting process was investigated in detail and the structure of the resulting composite film was elucidated using ellipsometry, X-ray Photoelectron Spectroscopy (XPS), Rutherford backscattering spectroscopy (RBS), and Conductive atomic force microscopy (C-AFM). The obtained data suggests that the grafting process occurs not only at the poly(4-bromostyrene), PS-Br/polymerization solution interface, but also deeply inside the swollen PS-Br film, which is penetrable for the catalyst and the monomer. The process results in an interpenetrated PS-Br/P3HT network, in which relatively short poly(3-hexylthiophene), P3HT grafts emanate from long, cross-linked PS-Br chains. A further method investigated during our work was to covalently graft regioirregular P3HT to substrates modified by macromolecular anchors using oxidative polymerization of 3HT with FeCl3. P3HT layers with variable thicknesses from 30 nm up to 200 nm were produced using two steps of polymerization reaction. The P3HT obtained by oxidative polymerization had always an irregular structure, which was a result of the starting monomer being asymmetric, which is undesired for electronic applications. The third method for the production of conductive polymer brushes was to graft regioregular poly(3,3''-dioctyl-[2,2';5',2'']terthiophene) (PDOTT) by electrochemical oxidative polycondensation of symmetrically substituted 3,3''-dioctyl-[2,2';5',2'']terthiophene (DOTT). A modification of the supporting ITO electrode by the self-assembled monolayers (SAMs) of compounds having polymerizable head-groups with properly adjusted oxidative potentials was found to be essential to achieve a covalent attachment of PDOTT chains. The polymer films produced show solvatochromism and electrochromism, as well as the previous two methods. After polymerization, the next step towards building organic electronic devices is applying the methods obtained in nano- and microscale production. Block copolymers constitute an attractive option for such surface-engineering, due to their ability to form a variety of nanoscale ordered phase-separated structures. However, block copolymers containing conjugated blocks are less abundant compared to their non-conjugated counterparts. Additionally, their phase behaviour at surfaces is not always predictable. We demonstrated in this work, how surface structures of non-conductive block copolymers, such as P4VP-b-PS-I, can be converted into (semi)conductive P4VP-b-PS-graft-P3HT chains via a surface-initiated polymerization of P3HT (Kumada Catalyst Transfer Polymerization (KCTP) from reactive surface-grafted block copolymers. This proves that our method is applicable to develop structured brushes of conductive polymers. We believe that it can be further exploited for novel, stimuli-responsive materials, for the construction of sensors, or for building various opto-electronic devices. The methods developed here can in principle be adapted for the preparation of any conductive block copolymers and conductive polymers, including other interesting architectures of conductive polymers, such as block copolymers, cylindrical brushes, star-like polymers, etc. To this end, one needs to synthesize properly-designed and multi-functional Ni-initiators before performing the polycondensation.

The aim of the present work was to screen the main methods for the synthesis of conjugated polymers for their suitability in the preparation of conductive polymer brushes. The main focus was put on the grafting of intrinsically soluble substituted regioregular polyalkylthiophenes because of their excellent optoelectronic properties. The resulting polymer films were characterized and their optoelectrical properties studied. For the first time, a synthesis of conductive polymer brushes on solid substrates using “grafting-from” method was performed. The most important, from my opinion, finding of this work is that regioregular head-to-tail poly-3-alkylthiophenes – benchmark materials for organic electronics - can be now selectively grafted from appropriately-terminated surfaces to produce polymer brushes of otherwise soluble polymers - the architecture earlier accessible only in the case of non-conductive polymers. In particular, we developed a new method to grow P3ATs via Kumada Catalyst Transfer Polymerization (KCTP) of 2-bromo-5-chloromagnesio-3-alkylthiophene. Exposure of the initiator layers to monomer solutions leads to selective chain-growth polycondensation of the monomers from the surface, resulting into P3AT brushes in a very economical way. The grafting process was investigated in detail and the structure of the resulting composite films was elucidated using several methods. The obtained data suggests that the grafting process occurs not only at the poly(4-bromstyrene) (PS-Br)/polymerization solution interface, but also deeply inside the swollen PS-Br films, penetrable for the catalyst and for the monomer The grafting process was investigated in detail and the structure of the resulting composite film was elucidated using ellipsometry, X-ray Photoelectron Spectroscopy (XPS), Rutherford backscattering spectroscopy (RBS), and Conductive atomic force microscopy (C-AFM). The obtained data suggests that the grafting process occurs not only at the poly(4-bromostyrene), PS-Br/polymerization solution interface, but also deeply inside the swollen PS-Br film, which is penetrable for the catalyst and the monomer. The process results in an interpenetrated PS-Br/P3HT network, in which relatively short poly(3-hexylthiophene), P3HT grafts emanate from long, cross-linked PS-Br chains. A further method investigated during our work was to covalently graft regioirregular P3HT to substrates modified by macromolecular anchors using oxidative polymerization of 3HT with FeCl3. P3HT layers with variable thicknesses from 30 nm up to 200 nm were produced using two steps of polymerization reaction. The P3HT obtained by oxidative polymerization had always an irregular structure, which was a result of the starting monomer being asymmetric, which is undesired for electronic applications. The third method for the production of conductive polymer brushes was to graft regioregular poly(3,3''-dioctyl-[2,2';5',2'']terthiophene) (PDOTT) by electrochemical oxidative polycondensation of symmetrically substituted 3,3''-dioctyl-[2,2';5',2'']terthiophene (DOTT). A modification of the supporting ITO electrode by the self-assembled monolayers (SAMs) of compounds having polymerizable head-groups with properly adjusted oxidative potentials was found to be essential to achieve a covalent attachment of PDOTT chains. The polymer films produced show solvatochromism and electrochromism, as well as the previous two methods. After polymerization, the next step towards building organic electronic devices is applying the methods obtained in nano- and microscale production. Block copolymers constitute an attractive option for such surface-engineering, due to their ability to form a variety of nanoscale ordered phase-separated structures. However, block copolymers containing conjugated blocks are less abundant compared to their non-conjugated counterparts. Additionally, their phase behaviour at surfaces is not always predictable. We demonstrated in this work, how surface structures of non-conductive block copolymers, such as P4VP-b-PS-I, can be converted into (semi)conductive P4VP-b-PS-graft-P3HT chains via a surface-initiated polymerization of P3HT (Kumada Catalyst Transfer Polymerization (KCTP) from reactive surface-grafted block copolymers. This proves that our method is applicable to develop structured brushes of conductive polymers. We believe that it can be further exploited for novel, stimuli-responsive materials, for the construction of sensors, or for building various opto-electronic devices. The methods developed here can in principle be adapted for the preparation of any conductive block copolymers and conductive polymers, including other interesting architectures of conductive polymers, such as block copolymers, cylindrical brushes, star-like polymers, etc. To this end, one needs to synthesize properly-designed and multi-functional Ni-initiators before performing the polycondensation.

Block copolymer (BCP) thin film patterns, generated using directed self-assembly (DSA) of diblock copolymers, have shown excellent promise as templates for semiconductor device manufacturing since they have the potential to produce feature pitches and sizes well below 20 nm and 10 nm, respectively, using current 193 nm optical lithography. The goal of this work is to explore block copolymers with sufficient thermodynamics driving force (as described by the Flory Huggins interaction parameter, χ) for phase separation at these smallest lengths scales. Here, poly(styrene)-b-poly(hydroxystyrene) is investigated since the PHOST domain is known to form extensive hydrogen bond networks resulting in increased χ due to this strong enthalpic interaction. In this work, nitroxide mediated polymerization (NMP) techniques were utilized to produce PS-b-PHOST diblock copolymers with a range of molecular weights (5000-30000) with low PDI approaching 1.2. The phase separation of low molecular weight PS-b-PHOST on neutral underlayer substrates via solvent annealing provided thin film vertical lamellae with 13 nm pitch. These results illustrate the improved resolution of PS-b-PHOST compared with the current industry standard of PS-b-PMMA (with 20 nm pitch). The directed self assembly of lamellar PS-b-PHOST patterns with 18 nm pitch via graphoepitaxy is demonstrated. Also, a highly selective atomic layer deposition (ALD) and etch technique was investigated which provided selective block removal of (PS-b-PHOST) block copolymer patterns which initially exhibited no inherent etch contrast. In this process, the PS domain is removed leaving a high fidelity etch relief pattern of the original block copolymer template. Finally, an alternative system is presented, namely Poly(trimethylsilylstyrene)-block-poly(hydroxystyrene) (PTMSS-b-PHOST), which utilizes silicon containing functionality in one of the blocks, providing high etch contrast. PTMSS-b-PHOST patterns were also exposed to oxygen plasma allowing selective block removal of the PS domain without the need for additional ALD processing steps.

Part of the research described in this thesis is conducted in collaboration with Centre d' étude et de Recherche sur les Macromolécules (CERM), Université de Liège, Sart-Tilman, Belgium / Les copolymères séquencés amphiphiles sont très prometteurs pour des applications de technologie de pointe en raison de leur capacité à s'auto-assembler dans des structures bien organisées à l'échelle du micro– et du nanométre, et de leur sensibilité à des stimulations de différentes natures. La formation des nanomotifs bien ordonnés dans les films et/ou en masse fournit un substitut à la nanolithographie et est utile pour le design et l'ingénierie de nanomembranes et de matériaux nanoporeux. L'auto–assemblage dans des solvants sélectifs, en incluant la sensibilité au pH et à la température, peut être ajusté pour correspondre aux besoins de différentes applications biomédicales, telles que l’encapsulation et/ou relargage de médicaments, l'ingénierie de tissus, etc. Dans ce contexte, des copolymères séquencés de type L–lactide (LLA) et méthacrylate 2–diméthylaminoéthyl (DMAEMA) sont d’un grand intérêt. Comme le contrôle sur l'auto–assemblage des copolymères séquencés est permis au niveau moléculaire, il est très important de préparer des copolymères bien définis avec des longueurs de bloc prévisibles et de faible polydispersité. Ainsi, une partie de cette étude a été consacrée au développement de procédures synthétiques optimales et à la caractérisation détaillée de copolymères di– et triblocs de LLA et de PDMAEMA. Un outil simple pour déterminer la présence d'homo–PLLA résiduel a été développée; cela a permis de déterminer et d'expliquer plusieurs voies de synthèse indésirables. La dernière inclut la participation possible de l'amorceur bifonctionnel utilisé, et nous avons alors proposé un système alternatif d'amorceur bifonctionnel/catalyseur. La racémisation du LLA par les unités amine de (P)DMAEMA a été observée pendant la polymérisation, limitant ainsi l'utilisation première du bloc PDMAEMA pour la préparation des copolymères PLLA–b–PDMAEMA. Les études thermiques et de cristallisation, en incluant les copolymères séquencés partiellement quaternisés, ont révélé un retard significatif de la vitesse de cristallisation, en présence du bloc de PDMAEMA. Nous avons constaté que les blocs sont miscibles pour de faibles masses molaires et que la miscibilité partielle est maintenue après quaternisation. Selon la longueur et le taux de quaternisation du bloc PDMAEMA, la cristallisation du PLLA a été étudiée dans un environnement restreint et confiné, faiblement ou fortement. La torsion des lamelles cristallines observée pour certains copolymères biséquencés a été accentuée dans les copolymères triséquencés, où la formation de sphérolites annelés a été observée dans toutes les conditions thermiques utilisées. / Multi–functional amphiphilic block copolymers have much promise for various high technology applications thanks to the controlled stimuli–responsive self–assembly into well–organized structures on the micro– and nanometer scales. The formation of well–ordered nanopatterns in films and/or in bulk provides a competitive substitute to nanolithography and is useful in the design and engineering of nanomembranes and nanoporous materials. Solution self–assembly in selective solvents, including pH and temperature sensitivity, can be tuned to match the needs of different biomedical applications, such as drug encapsulation/delivery, tissue engineering, etc. In this context, block copolymers of L–lactide (LLA) and 2–dimethylaminoethyl methacrylate (DMAEMA) are of great interest. Since the control over self–assembly of block copolymer systems is enabled on a molecular level, it is of great importance to prepare well–defined block copolymers with predictable block lengths and low polydispersity. Thus, a major part of the research in this study was devoted to developing optimal synthetic procedures with detailed characterization of linear di– and triblock copolymers of LLA and PDMAEMA. A simple tool to determine homo–PLLA impurity was developed, which helped to determine and explain several undesired routes. The latter includes possible involvement of the bifunctional initiator used, and an alternative bifunctional initiator/catalyst system was proposed. Racemization of LLA by (P)DMAEMA moieties was observed during LLA polymerization thus limiting the utilization of PDMAEMA–first approach for the preparation of PLLA–b–PDMAEMA. Thermal and crystallization studies, including on quaternized block copolymers, revealed a significant retardation effect of the PDMAEMA block on the crystallization kinetics. The blocks were found to be miscible in the melt at low molecular weights, and maintained partial miscibility after quaternization. Depending on the length and the quaternization degree of PDMAEMA, PLLA crystallization was studied in a templated, soft or hard confinement environment. Crystalline lamellae twisting observed in certain diblock copolymers was facilitated in triblock copolymers, where the formation of banded spherulites was observed in all thermal conditions used.

L’auto-assemblage de copolymères à blocs amphiphiles est un outil puissant de la chimie supramoléculaire pour la conception de nano-objets complexes et fonctionnels. Dans ces travaux de thèse, l’étude approfondie d’un copolymère à blocs « hybride » synthétique-b-peptidique poly(triméthylène carbonate)-b-poly(acide glutamique) pour des applications de vectorisation a été menée. Des morphologies vésiculaires, obtenues par auto-assemblage en voie « co-solvant » et présentant une grande stabilité ainsi qu’un caractère stimulable ont été mises en évidence. Une transition inédite en température, par des phénomènes de fusion et de fission, a pu être observée. L’encapsulation dans ces vésicules polymères d’un principe actif anti-tumoral et de nanoparticules magnétiques, à des taux très élevés, permet d’améliorer le contraste en IRM ainsi que de moduler la libération de la molécule par une variation des paramètres environnementaux (pH, T) ou par un effet d’hyperthermie magnétique. / Block copolymer self-assembly is a powerful tool within supramolecular chemistry to design smart and functional nano-objects. In this thesis work, comprehensive study of hybrid poly(trimethylene carbonate)-b-poly(glutamic acid) block copolymers for drug delivery applications has been conducted. Highly stable vesicular morphologies presenting stimuli-responsive behaviour were prepared using a solvent-injection method. In particular, original temperature responsiveness mediated by fusion and fission events has been evidenced. Dual loading of an anticancer drug and superparamagnetic nanoparticles in these vesicles, at very high loading contents, allows enhancing MRI contrast and controlling drug release kinetics by varying environmental conditions (pH, T) or by using a magnetic hyperthermia effect.

Dans le contexte d'un développement durable, les véhicules électriques apparaissent comme une solution incontournable dans le futur. Parmi les dernières évolutions sur les batteries, les systèmes constitués d'une électrode au lithium (technologie lithium métal) présente des performances remarquables en termes de densité d'énergie. L'inconvénient majeur de cette méthodologie est lié à la formation de dendrites lors de la recharge susceptibles d'occasionner des courts-circuits conduisant à l'explosion de la batterie. C'est dans cet axe que s'inscrit mon sujet de thèse dont l'objectif est de développer un électrolyte polymère solide présentant une conductivité ionique élevée (2.10-4 S.cm-1 à40°C) et une tenue mécanique suffisante (30 MPa) pour limiter les phénomènes de croissance dendritique. Pour cela, la polymérisation contrôlée par les nitroxydes (NMP) a été utilisée pour synthétiser des copolymères à blocs avec un bloc possédant des groupes d'oxyde d'éthylène –CH2-CH2-O- permettant la conduction des ions lithium et un bloc de polystyrène assurant la tenue mécanique de l'électrolyte final. Le bloc assurant la conduction ionique des architectures ainsi synthétisées sont constituées soit de POE sous forme linéaire soit de POE sous forme de peigne. / In the context of sustainable development, electric vehicles appear to be a major solution for the future. Among the lastest technologies, the Lithium Metal Polymer battery has presented very interesting performances in terms of energy density. The main drawback of this system is the formation of lithium dendrites during the refill of the battery that could cause short circuits leading to the explosion of the battery. The aim of my PhD is to develop a Solid Polymer Electrolyte showing a high ionic conductivity (2.10-4 S.cm-1 at 40°C) and a high mechanical strength (30 MPa) to prevent dendritic growth. For that purpose, Nitroxide Mediated Polymerization is used to synthesize block copolymers with a PEO moiety for ionic conduction –CH2-CH2-O- and polystyrene for mechanical strength. Different kind of architectures have been synthesized : block copolymer with linear PEO moiety or with grafted PEO moiety.