Bioorganisch-synthetische Blockcopolymere sind sowohl für die Materialwissenschaft als auch für die Medizin hochinteressant. Diese Arbeit beschäftigte sich mit neuen Synthesewegen für die Herstellung dieser Blockcopolymere. Zunächst wurde der klassische Ansatz zur Herstellung eines Blockcopolymers über die Kupplung der beiden Segmente aufgegriffen. Hierzu wurde eine Methode zur Synthese von selektiv säureendfunktionalisierten Polyacrylaten mittels einer terminalen Benzylesterschutzgruppe vorgestellt. Für die Herstellung von bioorganisch-synthetischen Blockcopolymeren mit einem größeren Polymersegment wurde daher ein anderer Syntheseansatz entwickelt. Dieser geht von einem funktionalisierten Oligopeptid aus, an dem durch Polymerisation das synthetische Segment aufgebaut wird. Der Aufbau erfolgte durch kontrolliert radikalische Polymerisation, um ein möglichst definiertes Segment zu erhalten. Zunächst wurde eine Synthese von Oligopeptid-Makroinitiatoren für die ATRP-Polymerisation durchgeführt. Es konnte gezeigt werden, dass in geeigneten polaren Lösungsmitteln (DMSO, DMF) eine Polymerisation mit dem ATRP-Oligopeptid-Makroinitiator erfolgreich ist. Allerdings treten während der Polymerisation Wechselwirkungen zwischen dem Katalysator und dem Oligopeptid auf. Eine Alternative bietet die RAFT-Polymerisation, da sie ohne einen Katalysator durchgeführt wird. Es gelang ausgehend von dem Oligopeptid-ATRP-Makroinitiator den Überträger herzustellen. Die RAFT-Polymerisation mit einem Oligopeptidüberträger stellt eine wichtige Methode für die Herstellung von bioorganisch-synthetischen Blockcopolymeren dar. Sie besitzt eine hohe Toleranz gegenüber funktionellen Gruppen. Die so hergestellten Blockcopolymere sind frei von Verunreinigungen, wie z.B. Übergangsmetallen. Dabei läßt sich das Molekulargewicht des synthetischen Blocks bei einer Polydispersität um 1,2 gut kontrollieren. / Bioorganic – synthetic conjugates have received a lot of attention concerning their potentials in the fields of material science, pharmaceutics and medicine. This work presents new synthetic routes to these conjugates. For conjugates consisting of small blocks an approach via coupling is possible. For larger blocks it was necessary to develop a different approach via controlled radical polymerisation methods. To begin with oligopeptide macroinitiators for Atom Transfer Radical Polymerisation were synthesized and successful applied in polymerization. The reaction conditions were optimized by studying the polymerisation kinetics. Although the polymerization results in well-defined products, interactions between the copper catalyst and the peptide are evident and cannot be suppressed. To overcome this problem the polymerization method had to be changed. Therefore oligopeptide-based reversible addition fragmentation transfer (RAFT) agents were developed. Well-defined conjugates comprising sequenz-defined peptides and synthetic polymers could be accessed by applying RAFT polymerization techniques in combination with the peptide macrotransfer agents. Polymerization reactions of n-butyl acrylate were performed in solution, yielding peptide-polymer conjugates with controllable molecular weight and low polydispersities.

The research project aimed to synthesise semiconducting polymer brushes (polymer chains densely grafted to a surface) utilising simple and efficient organic chemistry methods, with a view to use in molecular-level electronic applications. Conjugated polymers were initially chosen for their ability to conduct electrical charge along a polymer chain by facilitating electron transfer between π-bonds. Polymers also aimed to be living , which could allow for further chain growth at a later point in time. This could lead to the production of various useful brush block co-polymers, with different blocks (or layers) of polymers having different chemical, structural and electronic properties. Initially, several syntheses towards monomers for poly(phenyl isocyanide) and poly(quinoxaline-2,3-diyl) were undertaken with limited success. Attention was turned to the synthesis of poly(thiophene)s by Kumada catalyst-transfer polymerisation (KCTP), again with varying success. After this, ring-opening metathesis polymerisation (ROMP) was explored as a possible avenue. The successful synthesis of several cyclopropenes for use as monomers was carried out. However, the ROMP of these monomers failed. ROMP of unsubstituted norbornene was successful. XPS studies suggested that vapour deposition of SAMs (Self Assembled Monolayers) gave homogenous monolayers. Solution-phase depositions appeared prone to inhomogeneous multilayer deposition. Vapour deposited SAMs gave better grafting densities at lower deposition pressures, leading to thicker polymer brushes. Finally, atom transfer radical polymerisation (ATRP) methods have been investigated. ARGET-ATRP was determined as the favoured method as it uses lower quantities of copper. Functionalised monomers for ATRP were synthesised, but homopolymers of these polyaromatic monomers have been difficult to synthesise by both copper-mediated ATRP and AIBN initiation. Polymer brushes and polymer brush diblocks of post-polymerisation modified PHEMA and PDMAEMA have been successfully grown on silicon wafers and glass slides, with a view to using the diblocks of these polymers as effective bulk heterojunction photovoltaic devices. The kinetics of the growth of both polymers by the ARGET and ATRP methods were studied to determine the degree to which each polymerisation is living; to determine if diblock growth would be possible. PHEMA brushes were successfully modified with a range of polyaromatic acid chlorides. Focussing on anthracene (which has excellent fluorescence properties, displaying a clear ability to move electrons between energy levels), this attachment was further confirmed by a range of techniques, before successfully growing a brush diblock of the unfunctionalised and functionalised polymers.

Orientador: Valdemiro Pereira de Carvalho Júnior / Banca: André Luiz Bogado / Banca: Ana Maria Pires / Resumo: A investigação de sistemas catalíticos duais capazes de mediar as reações de polimerização por abertura de anel via metátese (ROMP) e de polimerização radicalar por transferência de átomo (ATRP) simultaneamente é de grande interesse e importância na obtenção de novos materiais com potencial de aplicação. Neste estudo, novos complexos de Rutênio(II) coordenados a diferentes carbenos N-heterocíclicos derivados de cicloalquilaminas (ciclopentil (IPent) (1a), ciclohexil (IHex) (1b), cicloheptil (IHept) (1c) e ciclooctil (IOct) (1d)) foram sintetizados: [RuCl2(S-dmso)2(IPent)] (2a), [RuCl2(S-dmso)2(IHex)] (2b), [RuCl2(S-dmso)2(IHept)] (2c) e [RuCl2(S-dmso)2(IOct)] (2d). Os sais imidazólicos e seus respectivos complexos de rutênio foram caracterizados por FTIR, UV-Vis, RMN e voltametria cíclica, comprovando-se o sucesso na síntese dos mesmos. Os complexos planejados foram avaliados como precursores catalíticos em reações de ROMP de norborneno (NBE) e em reações de ATRP de metacrilato de metila (MMA). As sínteses de polinorborneno (poliNBE) via ROMP com os complexos 2a-d como pré-catalisadores foram avaliadas sob condições de reação ([EDA]/[Ru] = 28 (5 µL), [NBE]/[Ru] = 5000, temperatura de 50 ºC, utilizando clorofórmio como solvente, variando o tempo até 60 minutos. A polimerização de MMA via ATRP foi conduzida usando os complexos 2a-d na presença de etil-α-bromoisobutirato (EBiB) como iniciador. Os testes catalíticos foram avaliados em função do tempo de reação usando a razão... / Abstract: The investigation of dual catalytic systems able to mediate simultaneously ring-opening metathesis polymerization (ROMP) and atom-transfer radical polymerization (ATRP) reactions is of great interest and importance in obtaining new materials with potential for application. In the study, new complexes of Ruthenium (II) coordinated to different N-heterocyclic carbenes derived from cycloalkylamines (cyclopentyl (IPent) (1a), cyclohexyl (IHex) (1b), cycloheptyl (IHept) (1c) and cyclooctyl (IOct) (1d), [RuCl2(S-dmso)2(IHept)] (2a), [RuCl2(S-dmso)2(IHex)] (2b) [RuCl2(S-dmso)2(IHept)] (2c) and [RuCl2(S-dmso)2(IOct)] (2d). The imidazole salts and their respective ruthenium complexes were characterized by FTIR, UV-Vis, NMR and cyclic voltammetry, proving the success in their synthesis. The planned complexes were evaluated as catalytic precursors in norbornene ROMP (NBE) reactions and in methyl methacrylate (MMA) ATRP reactions. The polynorbornene (polyNBE) syntheses via ROMP with complexes 2a-d as pre-catalysts were evaluated under reaction conditions ([EDA] / [Ru] = 28 (5 μL), [NBE] / [Ru] = 5000, The polymerization of MMA via ATRP was conducted using the complexes 2a-d in the presence of ethyl α-bromoisobutyrate (EBiB) as the initiator.The catalytic tests were evaluated As a function of the reaction time using the molar ratio [MMA] / [EBiB] / [Ru] = 1000/2/1. All ATRP experiments were conducted at 85 °C. The linear correlation of ln ([MMA]0 / [MMA]) as a function of time in MMA ATRP... / Mestre

Recently, a particular interest has been devoted to “smart”/stimuli-responsive amphiphilic polymeric materials. Strictly speaking, such structures do not present an amphiphilic character but can be transformed as such by external stimuli within their close environment, e.g., pH, temperature, light, ionic strength, ... and are then able to produce reversible self-assemblies greatly attractive in the biomedical field as drug delivery systems. The originality of this thesis relies upon the synthesis of “intelligent” hydrophilic triblock copolymers containing acrylamide and acrylate-based monomers presenting both thermo- and pH-responsiveness. The applied synthetic strategy aimed at performing the controlled copolymerization reactions entirely in aqueous conditions and in a “one-pot process” via Atom Transfer Radical Polymerization (ATRP). This synthetic approach represents a real challenge knowing that ATRP of (meth)acrylamide comonomers is difficult to control in aqueous medium. However, by the help of kinetic studies and related theoretical modeling, a fine control over the copolymerization process has been made available allowing the synthesis of polyacrylamide-based triblock copolymers with different charge states. Ultimately, all series of triblock copolymers have been investigated for forming polyelectrolyte complexes potentially useful as drug delivery (nano)systems. The first part of the thesis aims at reporting the control and the understanding of the aqueous ATRP of N-isopropylacrylamide (NIPAAm) initiated by a model low molecular weight initiator. The NIPAAm polymerization has been kinetically studied varying different parameters. Correlated with a theoretical modeling, the reactions involved in the ATRP process have been identified highlighting the importance of molecular diffusion limitations. This step was crucial in view to extrapolate to the synthesis of poly(N-isopropylacrylamide)-based copolymers. The second part focuses on the controlled synthesis of poly(ethylene oxide)-b-poly(N- isopropylacrylamide) diblock copolymers using the macroinitiator method. Different conditions such as solvent mixture, nature of the catalyst and of macroinitiator, i.e., poly(ethylene oxide), have been studied ultimately yielding well-tailored polyacrylamide-based triblock copolymers based on NIPAAm, N,N-dimethylaminoethyl acrylate and 2-acrylamido-2-methyl-1-propane sodium sulfonate comonomers The “smart” character of the resulting triblock copolymers has been investigated affording in specific conditions micellar self-assemblies. Last but not least, polyelectrolyte complexes have been prepared by coulombic interactions between the resulting triblock copolymers, e.g., poly(ethylene oxide)-b-poly(N- isopropylacrylamide)-b-poly(N,N-dimethylaminoethyl acrylate) and poly(ethylene oxide)-b- poly(N-isopropylacrylamide)-b-poly(2-acrylamido-2-methyl-1-propane sodium sulfonate) whose the thermo-responsiveness could be highlighted. The so-formed polyelectrolyte complex nanoparticles constitute promising nanovectors of the third generation able to kinetically tune the drug release in function of local temperature variation.

Non-polar phase selective solubility of modified poly(4-n-alkylstyrene) supports can be measured using fluorescent dyes as catalyst surrogates with thermomorphic and latent biphasic systems. By modifying the solvent compositions in heptane/ethanol and heptane/N, N-dimethylacetamide, increased non-polar phase selective solubility of modified polystyrene supports can be attained. Likewise, by varying the structure and length of the pendant alkyl chain, an increase in non-polar phase selective solubility is measured. These heptane soluble polymer supports can be useful for applications involving heptane soluble polymer-bound reagents and catalysts. Various polar and non-polar polymer supports were synthesized with an attached solvatochromic catalyst surrogates to determine the solvent accessibility of the supported species in pure and mixed solvents. The results of these studies indicate that in pure solvents, the influence of both polar and non-polar polymer supports on the solvent microenvironment of these polymer-supported probes is minimal. In mixed solvent systems, a polymer-like solvent microenvironment is measured in solvent mixtures comprised of solvents the polymer has unfavorable interactions. Poly(4-n-alkylstyrene) and internally functionalized polyisobutylene supports are two such polymer supports that exhibit this behavior. For terminally functionalized polymers in mixed solvents, the solvatochromic behavior does not indicate a collapsed structure. In mixed solvents, there is minimal influence of the polymer support on the solvent microenvironment of these terminally functionalized polymers. The application of soluble polyisobutylene supported copper complexes in the ATRP polymerization of styrene was investigated. Using the difference in solubility of the product polystyrene and the polyisobutylene copper complex in heptane, a solid/liquid separation of the soluble copper complex from the solid product was achieved. The results of these polymerizations indicate that the polyisobutylene copper complex behaves exactly like a low molecular weight copper complex in terms of control over molecular weight and molecular weight distribution. After the polymerizations, the polyisobutylene complexes could be separated as a heptane solution and recycled in multiple polymerizations of styrene.

A study of the atom transfer radical polymerisation (ATRP) of water-soluble, acidic, monomers was carried out in aqueous media. The ATRP of sodium methacrylate (MAANa) produced polymers with controlled molecular weights and narrow polydispersities (Me/M, - 1.3) at 90°C. This is the first reported example of direct polymerisation of an acidic monomer via ATRP. Previously, such acidic polymers were produced by polymerisation of protected monomers. In this thesis, copper(l) bromide and iron(II) bromide were investigated as ATRP catalysts. Both were found to be effective when solubilised by 2,2'-bipyridine (bipy). Monomer conversions between 75 and 85 % were obtained in the presence of Cu(l)Brlbipy, and conversions as high as 94 % were obtained in the presence of Fe(II)Br2Ibipy. Kinetic studies carried out on the ATRP of MAANa using the CuBrlbipy catalyst and an oligo(ethylene glycol)-based initiator indicated that polymerisation proceeded via first order kinetics with respect to monomer consumption, and that molecular weight increased linearly with conversion. This is as expected for a living polymerisation. At approximately 75 - 85 % conversion, however, premature termination occurred. Both bromine microanalyses and 'n and 13CNMR studies indicated that the halide-capped polymer chain-ends undergo HBr elimination. Low molecular weight « 10,000 g mol") MAANa homopolymers and oligo(ethylene glycol)-sodium methacrylate block copolymers (PEG-b-PMAANa) were examined as possible macro initiators for the ATRP of sodium 4-styrenesulfonate (SSNa), potassium 3- sulfopropyl methacrylate (SPMAK) and sodium allyl sulfonate (SAS). PEG-b-PMAANa was found to initiate the ATRP of SSNa, yielding a polymer with controlled molecular weight and a polydispersity of 1.23. Initiation of the ATRP of SPMAK and SAS was less successful. This was likely due to the loss of functionality of the MAANa-based polymers. Block copolymers were obtained, however, by macroinitiating the aqueous ATRP of MAANa using a monomethoxy-capped oligo(ethylene glycol) methacrylate homopolymer. Successful ATRP of MAANa was also achievable at ambient temperatures in the presence of a co-solvent, 2-(dimethylamino)ethanol, DMAE. DMAE appears to dramatically increase the rate of polymerisation whilst still maintaining control when used in equimolar quantities (relative to the monomer). Polymers with predetermined molecular weights and narrow polydispersities were produced in good yield (up to 86 % conversion) within five minutes at 20°C. The ATRP of other hydrophilic monomers was also investigated, albeit in less detail. These monomers included sodium acrylate, mono-2-(methacryloyloxy)ethyl succinate, 2- hydroxyethyl acrylate, itaconic acid, and 2-acrylamido-2-methyl-propanesulfonic acid. Generally less control was achieved for such syntheses than for the ATRP of MAANa.

Atom transfer radical polymerization (ATRP) is a dynamic technique that possesses tremendous potential for the synthesis of novel polymeric materials not possible through conventional free radical polymerization. However, its use on an industrial scale has been limited by the high level of transition metal complex required. Significant advances have been made in the last 5 years towards lowering the level of copper complexes used in ATRP, resulting in novel variants called “activator regenerated by electron transfer” (ARGET) and “single electron transfer-living radical polymerization” (SET-LRP). To fully realize the potential of ATRP, its use in industrially relevant processes must be studied. Continuous processes such as tubular flow reactors and stirred tank reactors (CSTR) can reduce waste, improve productivity and facilitate process scale-up when compared to common batch reactors. The combination of low copper concentration ATRP techniques and continuous processes are especially attractive towards the design of a commercially viable process. This thesis presents a study into ARGET ATRP and SET-LRP as applied to continuous tubular and stirred tank reactors for the production of acrylic and methacrylic polymers. The equilibrium which governs polymerization rate and control over molecular architecture is studied through batch ARGET ATRP experiments. The improved understanding of ARGET ATRP enabled the reduction of ligand from a 3 to 10 fold excess used previously down to a stoichiometric ratio to copper salts. ARGET ATRP was then adapted to a continuous tubular reactor, as well as to a semi-automated CSTR. The design of the reactors and the effect of reaction conditions such as reducing agent concentration and residence time are discussed. The use of common elemental copper(0) such as copper wire and copper tubing is also investigated with SET-LRP for room temperature polymerization of methyl acrylate. SET-LRP is adapted to a CSTR to observe the effects of residence time on reaction rate, molecular weight control as well as copper consumption rate. The use of copper tubing as a catalyst source for SET-LRP is demonstrated and the design of a continuous tubular reactor using a combination of copper and stainless steel tubing is discussed. / Thesis (Ph.D, Chemical Engineering) -- Queen's University, 2012-04-30 16:01:28.916

Functional nanoparticles have garnered considerable attention due to their intriguing physical properties at the nanoscale for a broad range of applications, such as photocatalysis, capacitive energy storage, thermoelectric power generation, solar energy harvesting, flexible and transparent electronics, drug delivery, biomolecular electronics, and analytic chemistry, etc. Successful synthesis of nanoparticles and precise control over their shapes are critical to achieving desired functions. In the first part of my thesis, an effective synthetic route to plain nanoparticles is briefly introduced. Based on this general route, the synthesis of solid iron oxide nanoparticles and a slightly modified synthetic method of solid silica nanoparticles are presented in detail. In the second part of my thesis, simulation of optical absorption spectra and plasmonic near-field maps of gold nanoparticle and gold/titanium oxide nanoparticle are explored, and the effectiveness of simulation in predicting, optimizing, and guiding experimental design is emphasized.

Aggregation-induced emission (AIE) is a phenomenon with many applications, such as chemical sensors, biological probes, immunoassay markets, and active layers in fabricating organic light-emitting diodes. AIE materials in polymers can enhance the emissivity of such materials while having the benefits of polymeric materials. This thesis examines the use of AIE polymers to study the effect of structure on the properties. This is done by first synthesizing a monomer with AIE characteristics, tetraphenylethylene-methacrylate (TPEMA). Secondly, polymerizing TPEMA using free and controlled radical polymerizations. Finally, the copolymerization of TPEMA with methyl methacrylate (MMA) to understand the effect of spaced-out TPE groups in the polymer chain on the photoluminescence of the polymer. The structures of all intermediates and final products were characterized by nuclear magnetic resonance (NMR) and size exclusion chromatography (SEC). The AIE characteristics were proven and compared using the photoluminescence graphs, showing that the homopolymer had increased emission intensity than its monomer. The copolymer had higher emission intensity than TPEMA and higher normalized emission intensity than that of the homopolymer, showing the effect of structure on the photoluminescence. Both the homopolymer and the copolymer were easier to aggregate than the monomer, making it more effective to utilize the material in applications where it needs to be emissive in diluted solutions. The glass transition temperature and the tacticity of the homopolymer and copolymer were also compared. The thesis is divided into the following five chapters; 1. Introduction, where a brief background along with the scope of the thesis is provided; 2. Literature Review, where a summary of controlled radical polymerization and AIE is given; 3. Experimental Section, where the materials' detailed procedure and characterization are provided; 4. Results and Discussion, where results of successful experiments are discussed; 5. Concluding Remarks, where the results are summarized, and future work is discussed.

Les travaux présentés dans ce manuscrit ont porté sur l'élaboration de nouveaux copolymères dibloc amphiphiles (poly(ε-caprolactone)-b-poly(méthacrylate d'oligo(éthylène glycol) méthyl éther) biodégradables, thermostimulables et susceptibles d'être employés dans des applications respectueuses de l'environnement comme le traitement des eaux contaminées. La particularité de ces copolymères provient d'une part de la différence de solubilité des deux blocs et d'autre part de l'association d'un bloc hydrophobe biodégradable à un bloc thermostimulable hydrophile. Les propriétés de ces copolymères en milieu aqueux ont ainsi été évaluées en fonction de la température. Ces composés ont été obtenus par la combinaison de deux techniques de polymérisation contrôlée en utilisant un amorceur difonctionnel. Pour cela, deux stratégies ont été testées : i) la polymérisation par ouverture de cycle (POC) de l'ε-caprolactone à partir d'un macro-amorceur de poly(méthacrylate d'oligo(éthylène glycol) méthyl éther) à terminaison OH après avoir mis au point les conditions expérimentales de la POC en comparant plusieurs catalyseurs. ii) par polymérisation radicalaire par transfert d'atome (ATRP) du méthacrylate d'oligo(éthylène glycol) amorcée à partir d'une poly(ε-caprolactone) à extrémité bromée. Les températures critiques inférieures de solubilité (LCST) de ces copolymères ont été déterminées par UV visible. Leurs comportements micellaires ont été étudiés par mesures HPPS / The development of new biodegradable diblock copolymers poly(ε-caprolactone)-b-poly[oligo(ethylene glycol)methyl ether methacrylate], which could be used in environmental friendly applications such as treatment of contaminated water has been the main goal of this work. For the preparation these copolymers, the ring-opening polymerization (ROP) and the Atom Transfer Radical Polymerization (ATRP) were combined by using a bifunctional initiator. The two-step route for the synthesis of these copolymers was using either ATRP or ROP as first step and the other polymerization secondly. Each polymerization was studied carefully in order to control the macromolecular parameters of the copolymers. On the one hand, the ATRP of methacrylates bearing oligo(ethylene glycol) was carried out by using poly(ε-caprolactone) with bromide end-group as macroinitiator. On the other hand, the ring opening polymerization of ε-caprolactone was initiated by the hydroxyl end-group of the poly[oligo(ethylene glycol)methyl ether methacrylate], using tin octoate, tin tetrakis(phenylethynyl) or bismuth triflate as catalysts. The Low Critical Solution Temperature (LCST) of these amphiphilic diblock copolymers in aqueous medium have been determined by UV-visible spectroscopy. Their micellar behaviors were also studied by measuring size by HPPS