The preparation and characterisation of a number of fluorinated monomers capable of electrochemical polymerisation is described. Their electrochemical characteristics and the products of polymerisation are discussed 4,5,6,7-Tetrafluoroisothianaphthene was synthesised and its chemistry investigated. Attempts to electrochemically polymerise this to give a potentially narrow band-gap conducting polymer were generally unsuccessful. Other analogous monomers were also found to be difficult to polymerise by this method. New fluorinated polyphenylylenevinylene oligomers and polymers have been prepared. In addition, potential routes to high molecular weight polytetrafluorophenylenevinylenes have been being investigated. Oligomeric poly-2,3,5,6-tetrafluorophenylenevinylenes were prepared via a self nucleophilic displacement of the para fluorine in cis and trans organometallic derivatives of corresponding cis and trans 1-halo- 2-pentafluorphenylethenes.The attempted preparation of poly 2,3,5,6-tetrafluorophenylene- vinylene via two different soluble precursor derivatives is described. 2,3,5,6-tetrafluoro-l,4-xylene-bis(dialkyl sulphonium halides) were prepared with view to the preparation of soluble precursor derivatives of F-PPV. Preliminary work polymerising 2,3,5,6-tetrafluorobenzene- 1,4-diethanal with 1,4-dilithium-2,3,5,6-tetrafluorobenzene did provide polyalcohol type precursor polymers to F-PPV, but requires further developement.

Chapter 1 gives a general introduction to the field of electroactive organic compounds. The historical development of the field is outlined and then the more specific areas are described in detail. The properties of picolinium and quinolinium TCNQ salts are introduced and the extension of this to the molecules studied in this work developed. Two current areas of interest - second harmonic generation and molecular rectification - are then reviewed and the potential applications of the materials studied in this work highlighted. Chapter 2 discusses the synthesis of the materials and contrasts the two methods used. A discussion of the reaction mechanisms is given, as well as techniques for monitoring the course of reaction. The characterisation of the materials by a range of spectroscopic techniques is described. The solvatochromic behaviour of the materials is shown to conform with theoretical predictions and the observed mass spectra are shown to have some diagnostic importance. Chapter 3 gives a general introduction to Langmuir-Blodgett (LB) films starting once again from a historical perspective. The molecular requirements of suitable materials together with pressure/area per molecule measurements and the deposition process are described. The various methods available for the characterisation of LB films are described, as well as the many potential applications proposed within the general field of molecular electronics. Chapter 4 describes the experimental methods employed when using the Joyce Loebl Langmuir Trough. The importance of parameters such as cleanliness, sample purity and instrument calibration is stressed. Chapter 5 discusses the behaviour of the materials on the subphase and their resultant fabrication as LB films. The structure of the films is shown to be dependent on the hydrophobic chain length with a definite change in film structure occurring at a 15 carbon chain. Reasons for this are proposed and calculations of chromophore/hydrocarbon chain tilt angles on the basis of the proposed structure are given. A time dependent change in film structure is also discussed, as well as suggestions for future work.

Le Poly(vinylidene-fluoride) (PVDF) est un polymère piézoelectrique pouvant être utilisé comme capteur, actuateur ou pour de la récupération d'énergie. Son copolymère dérivé le poly(vinylidene-fluoride–trifluoroethylene) (P(VDF-TrFE)) possède des propriétés similaires tout en étant plus simple à préparer que le PVDF. Il est compatible avec une technologie tout imprimée pour fabriquer des dispositifs transparents sur des substrats flexibles. Le premier objectif de cette thèse est d'analyser l’intérêt des couches minces de P(VDF-TrFE) imprimées pour l'actuation et de comparer avec la dernière génération de polymères dérivés: le Poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) (P(VDF-TrFE-CTFE)). Après une étude des différentes compositions l'objectif est d'améliorer la compréhension des mécanismes de déformations pour ouvrir la voie à de nouvelles améliorations. Les travaux menés sont présentés ici en trois parties distinctes. La première est consacrée à l’étude des propriétés mécaniques et électriques des polymères. L'influence du taux de CTFE est analysée et les polymères séparés en 3 catégories distinctes en fonction de leur nature ferroélectrique. Les performances pour l'actuation de chacune de ces catégories sont étudiées. Deux figures de merites sont retenues : le déplacement (et la force) que peuvent générer l'actuateur et le coefficient de couplage pour comparer le coût en énergie du dispositif. Le choix d'un terpolymère adapté dépend de l'application envisagée et peut permettre une augmentation significative de la réponse mécanique comparé à un copolymère. En revanche le coût énergétique est toujours beaucoup plus important, au minimum le double, quelle que soit l'application .Cette première étude a aussi mis en évidence l'hystérésis et les non-linéarités dans la relation champ électrique-déformation des polymères. La deuxième partie reprend les relations constitutives de la piézoélectricité pour analyser plus avant les divergences entre la théorie et l'expérience. Ces divergences servent de points de départ à des hypothèses et modèles de déformation dans le copolymères et dans les terpolymères. De nombreuses observations indirectes montrent l'existence d'une transition de phase sous l'effet du champ électrique; en se basant sur les données de déformation et de polarisation, l'analyse présentée ici identifie une plage limitée de champ pour cette transition et quantifie son poids dans la déformation totale du matériau.La troisème partie est consacrée à la mise en évidence expérimentale des hypothèses de la partie précédente. La principale étude est l'observation in-situ de la transition de phase sous l'effet du champ par diffraction aux rayons X. Cette mise en évidence expérimentale confirme une partie des explications avancées et une étude en température permet d'aller plus loin en jouant sur la dépendance des phases à la température.Ces travaux apportent une analyse de la viabilité des différents polymères pour l'actuation. L'étude de la relation champ électrique-déformation apporte des outils pour la modélisation et une meilleure compréhension des mécanismes à l’œuvre dans ces matériaux. Les observations in-situ de la microstructure permettent de valider physiquement les modèles présentés. Ils apportent une meilleure compréhension de la physique même si de nombreuses zones d'ombre subsistent, notamment au niveau de la phase amorphe. / Poly (vinylidene-fluoride) (PVDF) is a piezoelectric polymer that can be used as a sensor, actuator or for energy harvesting. Its copolymer derivative poly (vinylidene-fluoride-trifluoroethylene) (P (VDF-TrFE)) has similar properties whilst being easier to process than PVDF. It is compatible with fully printed technologies to make transparent devices on flexible substrates. The first objective of this thesis is to analyze the interest of print thin films of P (VDF-TrFE) for the actuation and to compare with the last generation of derived polymers: Poly (vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) ( P (VDF-TrFE-CTFE)) terpolymers. After a study on the different compositions the objective is to improve the understanding of the deformation mechanisms to pave the way for new improvements. The work is presented here in three separate parts. The first is devoted to the study of the mechanical and electrical properties of polymers. The influence of the CTFE content is analyzed and the polymers separated into 3 distinct categories based on their ferroelectric nature. The performances for the actuation of each of these categories are studied. Two figures of merits are retained: the displacement (and the force) that can be generated by the actuator and the coupling coefficient to compare the energy cost of the device. The choice of a suitable terpolymer depends on the intended application and may allow a significant increase in the mechanical response compared to a copolymer. On the other hand the energy cost with a terpolymer is always much more important, at least twice that of a copolymer.This first study revealed hysteresis and nonlinearities in the electric field-strain relationship of polymers. The second part takes up the constituent relations of piezoelectricity to analyze further the divergences between the theory and the experiment. These divergences serve as starting points to understand and model the deformation in co- and ter-polymers. Many indirect observations show the existence of a phase transition under the effect of the electric field; based on deformation and polarization data, the analysis presented here identifies a limited field range for this transition and quantifies its weight in the total deformation of the material.The third part is devoted to the experimental demonstration of the hypotheses made in the modelling section. The main study is the XRD in-situ observation of the phase transition under the effect of an electrical field. This experimental evidence confirms some of the proposed explanation and a temperature study allows us to go further, making use of the dependence of phases stability to the temperature.This work provides an analysis of the viability of the various polymers for the actuation. The study of the electric field-strain relationship provides tools for modeling and a better understanding of the mechanisms at work in these materials. In-situ observations of the microstructure make it possible to physically validate the models presented. They bring a better understanding of physics even if many uncertainties remain, especially in the amorphous phase.

Ultramicroelectrodes (UMEs) are generally defined as electrodes with sizes ≤25 µm. UMEs can be prepared by several methods including by sealing a conductive filament like thin metal wire or a single carbon fiber in a glass capillary. The small size of UMEs makes them useful as probes for measuring electroactive species in confined spaces (for example, inside living cells, etc.), and also enables very effective mass transport, resulting in rapid achievement of steady-state response and facilitating measurement of fast electrochemical reactions. Application of UMEs often requires modification of the electrode surface to improve the selectivity and the sensitivity towards the target analyte. Surface modification methods are time-consuming and may require expensive equipment. Previous research in our group demonstrated that a simple soft nitriding method could be employed to introduce surface nitrogen on carbon fiber (CF). The technique improved electrochemical response of CF-UMEs towards hydrogen peroxide (a reactive oxygen species that has been related to various malignancies and disorders) and, in separate experiments, also enabled deposition of electroactive metal nanoparticles on the UME surface. Since the presence of phosphorus heteroatoms on carbon electrodes has been shown to impart similar benefits, here we investigate a simple phosphorus doping strategy to make P-doped CF-UMEs. We compare their properties towards the electrocatalytic reduction of H2O2 to both N-doped CF-UMEs and unmodified CF-UMEs.

Yes / Biomaterials capable of precisely controlling the delivery of agrochemicals/biologics/drugs/fragrances have significant markets in the agriscience/healthcare industries. Here, we report the development of degradable electroactive polymers and their application for the controlled delivery of a clinically relevant drug (the anti-inflammatory dexamethasone phosphate, DMP). Electroactive copolymers composed of blocks of polycaprolactone (PCL) and naturally occurring electroactive pyrrole oligomers (e.g., bilirubin, biliverdin, and hemin) were prepared and solution-processed to produce films (optionally doped with DMP). A combination of in silico/in vitro/in vivo studies demonstrated the cytocompatibility of the polymers. The release of DMP in response to the application of an electrical stimulus was observed to be enhanced by ca. 10-30% relative to the passive release from nonstimulated samples in vitro. Such stimuli-responsive biomaterials have the potential for integration devices capable of delivering a variety of molecules for technical/medical applications. / This research was funded by a variety of sources, and the authors acknowledge the UK Engineering and Physical Sciences Research Council (EPSRC) National Productivity Investment Fund (NPIF) for a PhD Studentship for M.D.A. (Grant references: EP/R512564/1, 2065445), in support of the EPSRC First Grant for J.G.H. (Grant reference: EP/ R003823/1); the UK Royal Society for support of J.G.H. (Grant reference: RG160449); and the UK Royal Society and CONICET (Argentina) for supporting M.D.A., S.M., M.F.D., and J.G.H. (Grant Reference: A103355).

Traditionally, water has been used as the diluent for ionomeric polymer transducers. The water mobilizes the counterions within the polymer and allows electromechanical transduction to occur. However, these water-swollen devices have limited stability when operated in a non-aqueous environment. In this work, ionic liquids are demonstrated as viable diluents for ionomeric polymer transducers based on Nafion membranes. Ionic liquids are molten salts that are highly thermally stable and have an immeasureably low vapor pressure. Therefore, the ionic liquid-swollen transducers exhibit enhanced stability in their performance when operated for long periods of time in air. Methods for swelling Nafion membranes with ionic liquids are presented. Also, techniques for plating the ionic liquid-swollen transducers with metal electrodes are discussed. The performance of the ionic liquid-swollen transducers is compared to that of water-swollen transducers and differences are observed. Apart from the superior stability of the ionic liquid-swollen devices, they are observed to not exhibit the characteristic back-relaxation that is often associated with water-swollen transducers and limits their low frequency response. In order to investigate the physics of transduction in the ionic liquid-swollen membranes, structured experiments are performed using two different ionic liquids: 1-ethyl-3-methylimidazolium trofluoromethanesulfonate (EMI-Tf), which is water miscible, and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMI-Im), which is hydrophobic. The other experimental parameters are the counterion of the Nafion membrane and the swelling level of ionic liquid. Small-angle X-ray scattering (SAXS) is used to characterize the morphology of the ionic liquid-swollen Nafion membranes. The SAXS testing reveals that the clustered morphology of the Nafion membrane is preserved by the EMI-Tf ionic liquid, which is compatible with the hydrophilic cluster phase. By contrast, the hydrophobic EMI-Im ionic liquid is found to disrupt the clustered morphology and lead to partial homogenization of the polymer. This has the effect of inhibiting the ionic conductivity. The SAXS testing also reveals that the mean intercluster spacing increases as the content of ionic liquid and size of the counterions increases. Based on assumptions regarding the swelling mechanism, this is thought to arise from an increase in the mean size of the clusters. Spectroscopic investigations were also performed using Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (NMR). These studies show that the ionic liquid interacts with the Nafion polymer by displacing the counterions away from the sulfonate exchange sites. The cations of the ionic liquid then associate with the sulfonate sites and the counterions associate with the anions of the ionic liquid. Above a certain critical uptake of ionic liquid, this displacement is complete and additional ionic liquid does not associate with the ions of the polymer. The critical uptake is found to decrease with increasing size of the counterions. / Ph. D.

The main objectives of this thesis are 1) to evaluate the effect of cross-linking polar cyano phenyl (CN) groups on poly (dimethyl siloxane) (PDMS) and 2) to characterize the electromechanical properties of the resulting CN-PDMS blend as an electroactive actuator. Materials responding to an external stimulus are referred to as electroactive materials. There are several phenomena, which govern the mechanism in these materials, such as piezoelectricity, Maxwell's effect, ferroelectricity, electrostriction to name a few. These electroactive materials can be employed in several applications such as biomedical devices, robots, MEMs, aerospace vehicles, where the application is governed by the specific mechanism. However in order for the materials to be used effectively, they need to be thoroughly characterized to understand their behavior under factors like electric field, temperature, frequency and time.The present work focuses on developing an electroactive actuator, which has tailorable properties, allowing a wide operational temperature window from -100°C to 200°C and stability in harsh conditions. The characterization of the CN-PDMS polymer blend is done in two folds. First the physical properties of the polymer system are characterized by performing tests such as Dielectric Spectroscopy, Differential Scanning Calorimetery and Thermally Stimulated Current measurement. These techniques offer complete understanding of the structure-property relationship and effects of the functional groups on the dielectric and relaxation behavior of the polymer. The Dielectric Spectroscopy and the Thermally Stimulated Current analysis are used to elucidate the primary and the secondary relaxations, such as molecular mobility, interfacial polarization and dipolar relaxation. Dielectric Spectroscopy reveals that the molecular weight of PDMS does not affect the dielectric permittivity of the polymer blend. Also, Dielectric Spectroscopy clarifies the role of the CN polar group in the polarization of the CN-PDMS blend, inducing electromechanical strain in the polymer blend through electrostriction.The Differential Scanning Calorimetery is used to quantify the thermal behavior of the CN-PDMS polymer blend by quantifying properties such as melting temperature (Tm) and re-crystallization temperature of the PDMS polymer cross-linked with CN functional group. Results reveal that the thermal characteristics of the blend are not affected when PDMS is cross-linked with the functional CN moieties, meaning CN-PDMS maintains the advantages of PDMS in terms of stability towards harsh conditions, wide operating temperature and resistance to ultraviolet radiations.Following the physical characterization, electromechanical characterization of the CN-PDMS polymer blend is done to assess the electromechanical strain induced in the blend in response to electric field. The electromechanical strain is studied in two configurations; the electromechanical strain induced along the length of the polymer blend and induced through the thickness of the blend. These strain measurements are performed by applying both direct current as well as alternating current electric fields, and the induced electromechanical strain is studied as a function of amplitude and frequency of the electric field as well as the time of application of the electric field. The mechanism behind the development of the electromechanical strain and the nature of the strain under electric field is elucidated. The performance of the electroactive polymer is compared with several other polymeric actuators such as PVDF and PVDF-TrFE, polyurethane based actuators and ionomers. Comparison gives favorable results in terms of strains. In addition, CN-PDMS polymer system has the advantage of allowing control of processing of the blend, which is not present in all the other commercial electroactive polymers. The maximum electromechanical strain yielded along the length of the CN-PDMS polymer blend is 1.74 % when an electric field of 0.2MV/m is applied along the length of the polymer. Through the thickness, the maximum induced strain is 0.12 % for an electric field of 0.8 MV/m. Based on the nature of the strain yielded it is observed that the strain induced in the CN-PDMS blend is consistently proportional to the square of the electric field (E2). Moreover, the strain is driven by the concentration of the dipolar moieties (CN) present in the polymer blend.All the above-mentioned techniques used for thermal and electromechanical characterization of the CN-PDMS polymer blend illustrate the electrostrictive nature of the polymer under the study.

Esta tese aborda quatro tópicos fundamentais para o desenvolvimento e aplicação de membranas eletroativas nanoestruturadas (MENs): (i) síntese e caracterização de nanopartículas (Nps) de prata, ouro e platina encapsuladas em moléculas de dendrímero poliamidoamina geração 4 (PAMAM); (ii) preparação de filmes automontados contendo PAMAM e Nps de ouro (PAMAM-Au); (iii) preparação de MENs utilizando sistema core-shell PAMAM-Au@Me, onde Me é um mediador redox; (iv) imobilização enzimática em MENs e estudos biocatalíticos associados a processos eletroquímicos. As Nps foram caracterizadas observando-se a banda plasmônica em espectros na região do UV-Vis. Imagens de microscopia eletrônica de transmissão revelaram que PAMAM-Au e PAMAM-Pt possuem morfologias esféricas, enquanto o PAMAM-Ag forma grandes cristais com estruturas fractais. Estruturas cúbicas de face centrada caracterizaram os cristais formados de Au e Pt, sendo possível estimar os diâmetros (3,0 nm) das Nps pela equação de Scherrer em difratogramas de raios X, confirmados posteriormente por microscopia eletrônica por transmissão (TEM). Um indício de estabilização por encapsulamento do híbrido PAMAM-Au foi obtido de espectros de infravermelho (FTIR), a partir de modificações nas bandas das amidas. A cinética de reação para formação de PAMAM-Au também foi estudada. Filmes de PVS/PAMAM-Au (onde PVS é o poli(ácidovinilssulfônico)) foram preparados com 5 minutos de imersão, com a mesma quantidade de material sendo adsorvida em cada camada, segundo medidas de espectroscopia UV-Vis e voltametria cíclica (CV). No caso do eletrodo ITO-(PVS/PAMAM-Au), saltos de elétrons foram considerados o mecanismo de transporte de carga ao longo do filme. Um novo sistema core-shell Au@PB foi preparado, formando um sistema ITO-(PVS/PAMAM-Au)6@PB, em que a eletrodeposição de PB (azul da Prússia) foi monitorada medindo-se as correntes faradaicas durante os ciclos potenciodinâmicos. Outros mediadores de hexacianoferratos de metais de transição (Fe, Ni, Co e Cu) foram obtidos sobre eletrodos de ITO-(PVS/PAMAM-Au). De resultados de espectroscopia de impedância eletroquímica (EIS), verificou-se que a resistência de transporte de carga decresce na sequência CuHCF > FeHCF > NiHCF > CoHCF e todos os eletrodos apresentaram atividade catalítica para o peróxido de hidrogênio. Uma nova configuração de eletrodo, ITO-(PVS/PAMAM-Au)3@CoHCF-GOx, pôde ser aplicada como dispositivo enzimático, com a glicose oxidase (GOx) sendo imobilizada por drop-coating na superfície do eletrodo e aplicada em experimentos de biocatálise. A glicose pôde ser detectada a 0,0 V (Ag/AgCl), com resposta linear até 100 µmol L-1 de glicose, sensibilidade de 115 nA mmol L-1, limite de detecção de 5,5 µmol L-1 e KMapp de 0,24 mmol L-1, mostrando que o sistema aqui proposto cria um ambiente propício para a enzima operar com alta atividade catalítica. / This thesis addresses four fundamental topics for producing and applying electroactive nanostructured membranes (ENMs): (i) synthesis of Au, Pt and Ag nanoparticles (Nps) using polyamidoamine (PAMAM generation 4) dendrimers as template/stabilizers; (ii) fabrication of layer-by-layer (LbL) films comprising PAMAM with AuNps (PAMAM-Au) and poly(vinylsulfonic acid) (PVS); (iii) preparation of a new core-shell system with Prussian blue (PB) around the Au nanoparticles (PAMAM-Au@PB); (iv) enzyme immobilization on ENMs and bioelectrochemistry studies. The formation of the Nps inside PAMAM was monitored by measuring the plasmonic band of NPs via UV-Vis spectroscopy. Images from transmission electron microscopy (TEM) showed well-organized Au and Pt spherical particles, with average diameter of 3 nm and narrow size distribution. In addition, X-ray diffraction of Nps enabled easy identification of the Nps atomic planes (face-centered cubic arrangements). However, PAMAMAg growth showed fractals structures. In order to confirm Au NPs encapsulation inside the PAMAM dendrimer, FTIR spectra in the transmission mode for neat PAMAM and PAMAM-Au were compared. The kinetics of formation of PAMAM-Au was studied by UV-Vis spectroscopy. The deposition of individual PAMAM-Au layers was examined in detail: the adsorption kinetics was determined by CV to be first-order and that 5 min of adsorption was sufficient for maximum coverage. Formation of PVS/PAMAM-Au multilayers showed a linear increase in anodic and cathodic peak currents, indicating that the same amount of material was adsorbed in each deposition step. Electron-hopping was inferred as the charge transport mechanism between PAMAM-Au layers. Using hexacyanoferrate (III) to probe the electrochemical reaction at the electrode surface, the charge transport in the PAMAM-Au layers was shown to be faster than for non-modified electrodes. A new system based on PAMAM-Au@PB was prepared by simple potential cycling electrodeposition after ITO-PVS/PAMAM-Au LbL film preparation. New systems are described based on ENM membranes of ITOPVS/ PAMAM-Au LbL electrodes, with a redox mediator (Me) electrodeposited around Au nanoparticles. The resulting ITO-PVS/PAMAM-Au@Me system was then characterised electrochemically using cyclic voltammetry and electrochemical impedance spectroscopy. We demonstrated that the concept of ENM can be generalized to a wider variety of redox mediators. All electrodes modified with hexacyanoferrates showed electrocatalytic activity towards hydrogen peroxide, which is promising for the preparation of nanodevices requiring redox mediators. An electrochemical enzyme device with glucose oxidase (GOx) immobilized at ITO-(PVS/PAMAM-Au)3@CoHCF ENM was developed. Using CoHCF as redox mediator, hydrogen peroxide (the enzymatic reaction product) was determined at 0.0 V (vs. SCE), with linear range up to 100 Zmol L-1 of glucose, sensitivity of 115 nA mmol L-1, detection limit of 5.5 Zmol L-1 and KM app of 0.24 mmol L-1. Such a performance indicates that this system promotes a friendly environment for enzyme immobilization.

Conjugated polyelectrolytes (CP) show interesting electrical and optical properties for organic electronics as well as for life science applications. Their possibilities of supramolecular assembly with nanowire like misfolded proteins, amyloids, as well as synthetic polypeptides or DNA forming conducting nano composites is highly interesting as being a truly bottom up approach for fabrication of OLEDs, photovoltaic’s as well as logic devices. A special class of CPs is that of electroactive cojugated polymers (ECPs), which, due to their structure, will exhibits a unique combination of properties, including the following; electrically conducting, ability to store an electric charge and ability to exchange ions. The positive or negative excess charge can be introduced into the conjugated polymer by means of chemical or electrochemical oxidation/reduction (a process called doping) following the polymerization reaction. In order to preserve overall electroneutrality of the polymer during introduction of excess charge, ionexhange processes occurs between the polymer phase and the surrounding electrolyte solution. This charge/discharge process can be utilized for application such as; pseudo super capacitors (energy storage through oxidation/reduction processes), electro mechanical actuators (convert electrical energy to mechanical energy) and sensors (converts a chemical signal to electrical conductivity). In this thesis we describes the synthetic challenges with ECPs for applications vide supra. These mostly relates to solubility, ionic functionalization, conductivity and macromolecular properties such as size and shape of the ECPs. The key requirement in the synthesis of ECPs is that the conjugated nature of the monomer is conserved in the synthesis process and that insertion of excess charge (doping) can be obtained. This limits both the choice of monomer and the choice of polymerization process. Monomers of great complexity have been synthesized with this careful goal in mind. Furthermore, the development of novel monomers must also target the appropriate functionality for polymerization. As such, most ECP monomers are electron-rich molecules with pendant groups containing pyrroles, thiophenes, or 3,4-ethylenedioxythiophenes. These three well known ECP monomers are excellent additions to conjugated systems as they typically enable electrochemical polymerization and direct the polymerizations toward linear polymers with good stability towards doping. The first topic of this thesis we demonstrate how we can obtain water soluble ECPs with good electrical conductivity by controlling the polymerization techniques and proper ionic functionalization of the monomer. We also show how these polymers can be incorporated by self-assembly with biomolecular templates, such as, DNA and amyloid fibrils, thus generating novel electrically conductive nanowires. The second topics of this thesis demonstrate how hydrogels of ECPs can be used as bioand charge storage materials, were we demonstrate electronically controlled cell release for biology applications. Both applications are based on ECPs ability to ionexhange processes during electrochemical redox reactions. As well as ions, solvent and other neutral molecules may enter the film during charge/discharge processes. This cause a swelling or shrinking of the ECP films and the expansion and contraction of the polymer network in conjugation with the sorption/desorption of solvent molecules and ions can be described in terms of mechanical work. In the first case we were able to synthesize a water soluble ECP with high amphiphilic character. The polymer was immobilized onto a flexible electrode, suitable for cell growth and subjected to a cell growth media. When the desired cell layer was formed we applied a potential to the flexible electrode. This resulted in that the mechanical work of the immobilized ECP during the applied potential overcame the week adhesive forces to the flexible electrode, which resulted in super swelling and disintegration of the ICP and the cell layer could be harvested. In the second case the possibilities of using synthetically modified ECPs as a dopant during electropolymerization of another ECP monomer to obtain a polymer integrated network with high charge density and good charge transport properties. We demonstrate how this polymer network can be used as porous electrodes suitable for supercapacitors.

Electroactive polymers (EAP) are an emerging branch of smart materials that possess the capability to change shape in the presence of an electric field. Opportunities for the advancement of knowledge were identified in the branch of EAP consisting of inherently electrically conductive polymers. This dissertation explores methods by which the unique properties of composite materials having conductive polymers as a constituent may be exploited. Chapter 3 describes the blending of polyaniline with conventional thermoplastics. Processing these polyblends into foams yielded a porous conductive material. The effect of blend composition and processing parameters on the resulting porous morphology and electrical conductivity was investigated. These findings represent the first systematic study of porous conductive polymer blends. In Chapter 4, multilayer electroactive polymer actuators consisting of polypyrrole films electropolymerized on a passive polymer membrane core were harnessed as actuators. The membrane is vital in the transport of ionic species and largely dictates the stiffness of the layered configuration. The impact of the mechanical properties of the membrane on the actuation response of polypyrrole-based trilayer bending actuators was investigated. Candidate materials with distinct morphologies were identified and their mechanical properties were evaluated. These results indicated that polyvinylidene difluoride membranes were superior to the other candidates. An electrochemical synthesis procedure was proposed, and the design of a novel polymerization vessel was reported. These facilities were utilized to prepare actuators under a variety of synthesis conditions to investigate the impact of conductive polymer morphology on the electromechanical response. Characterization techniques were implemented to quantitatively assess physical and electrochemical properties of the layered composite. Chapter 5 proposes a new unified multiphysics model that captures the electroactive actuation response inherent to conductive polymer trilayer actuators. The main contribution of this investigation was the proposal and development of a new hybrid model that unifies concepts from charge transport and electrochemomechanical models. The output of the proposed model was compared with published data and shown to be accurate to within 10%. Finally, Chapter 6 demonstrated the application of these materials for use as precision mirror positioners in adaptive optical systems.