To meet the predicted increase in demand for energy storage in tomorrow's society, the development of inexpensive, flexible, lightweight and sustainable energy-storage materials is essential. In this respect, devices based on electroactive organic molecules, such as conducting polymers, are highly interesting. The aim of this thesis was to evaluate the use of nanocellulose as a matrix material in composites of cellulose and the electroactive polymer polypyrrole (PPy), and the use of these composites in all-polymer paper-based energy-storage devices.   Pyrrole was polymerized using FeCl3 onto cellulose nanofibers in the form of a hydrogel. The resulting PPy-coated fibers were washed with water and dried into a high surface area, conductive paper material. Variations in the drying technique provided a way of controlling the porosity and the surface area of wood-based cellulose nanofibers, as the properties of the cellulose were found to have a large influence on the composite structure. Different nanocellulose fibers, of algal and wood origin, were evaluated as the reinforcing phase in the conductive composites. These materials had conductivities of 1–6 S/cm and specific surface areas of up to 246 m2/g at PPy weight fractions around 67%.   Symmetrical supercapacitor devices with algae-based nanocellulose-PPy electrodes and an aqueous electrolyte showed specific charge capacities of around 15 mAh/g and specific capacitances of around 35 F/g, normalized with respect to the dry electrode weight. Potentiostatic charging of the devices was suggested as a way to make use of the rapid oxidation and reduction processes in these materials, thus minimizing the charging time and the effect of the IR drop in the device, and ensuring charging to the right potential. Repeated charging and discharging of the devices revealed a 10–20% loss in capacity over 10 000 cycles. Upon up-scaling of the devices, it was found that an improved cell design giving a lower cell resistance was needed in order to maintain high charge and discharge rates.   The main advantages of the presented concept of nanocellulose-PPy-based electrical energy storage include the eco-friendly raw materials, an up-scalable and potentially cost-effective production process, safe operation, and the controllable porosity and moldability offered by the nanocellulose fiber matrix. Integrating energy storage devices into paper could lead to un- precedented opportunities for new types of consumer electronics. Future research efforts should be directed at increasing the energy density and improving the stability of this type of device as well as advancing the fundamental understanding of the current limitations of these properties.

The thesis describes an investigation into the interaction between the conducting polymer and cellulosic materials, and the preparation of electroconductive paper. The adsorption behavior of the conducting polymer onto cellulosic materials was characterized. Poly(3,4-ethylenedioxythiophene) doped with poly(4-styrene sulfonate) (PEDOT:PSS) was used as conducting polymer because of its attractive properties in terms of conductivity, water solubility, and environmental stability. The model substrate used for adsorption was microcrystalline cellulose (MCC). Various pH levels and salt concentrations were explored to completely understand the adsorption behavior of PEDOT:PSS. The variation in surface charge characteristics when the pH and salt concentration were changed was monitored by polyelectrolyte titration and zeta potential measurement. The adsorption isotherm showed a broad molecular distribution of the conducting polymer and considerable interaction between the polymer and MCC. As the pH of the solution was increased, the adsorbed amount decreased. With varying salt concentrations, the adsorption passed through a maximum. The extent of deposition of PEDOT:PSS on the surface of cellulosic fibers was investigated using X-ray Photoelectron Spectroscopy (XPS) with a commercial base paper as substrate. XPS analysis of dip-coated paper samples showed PEDOT enrichment on the surface. The degree of washing the dip-coated paper with acidic water did not significantly affect the PEDOT enrichment on the surface.   A base paper was coated with PEDOT:PSS blends to produce electroconductive papers. The bulk conductivities (σdc) of the coated papers were measured using a four-probe technique and impedance spectroscopy. One-side and two-side coating gave comparable conductivity levels. Various organic solvents added to the PEDOT:PSS dispersion at different concentrations showed various effects on the bulk conductivity of the coated paper. Blends containing sorbitol and isopropanol did not enhance the bulk conductivity of the coated paper, and at high concentrations these organic solvents lowered the conductivity. Paper samples coated with a PEDOT:PSS blend containing N-methylpyrrolidinone (NMP) and dimethyl sulfoxide (DMSO) exhibited a higher conductivity than when coated with pure PEDOT:PSS, due to conformational changes and their plasticizing effect. The effect of calendering was investigated and only the sample subjected to 174 kN/m line load after coating showed significant conductivity enhancement. The addition of TiO2 pigment lowered the bulk conductivity of the paper. Contact angle measurements were made to monitor the effect of coating the paper with PEDOT:PSS blends on the hydrophilicity of the paper samples. The amount of PEDOT:PSS deposited in the fiber network was determined using total sulfur analysis. Thus, this study makes use of conventional paper surface treatment as method for achieving bulk conductivity of paper in the semi-conductor range without significantly decreasing the paper strength. / Printed Polymer Electronics

<p>The focus of this study is to synthesize a novel hinged polymer actuator. The linking molecule (hinge) is phenazine with interconnected dipyrrole units.</p>

In this thesis, the development of a novel experimental technique for measuring the spontaneous, stochastic work function (WF) fluctuations of conducting polymer films, at equilibrium, is discussed. Polyaniline (PANI) is studied as a representative conducting polymer. This technique utilizes an insulated-gate field-effect transistor (IGFET) with PANI gate electrode (PANI-IGFET). The fluctuations of PANI WF are transduced into measurable drain current fluctuations of the device. By analyzing these fluctuations while systematically controlling the temperature, electric field and doping level, a model of WF fluctuations in PANI films is developed. These experiments suggest that the source of WF fluctuations is the hopping of charge carriers, or trapping/detrapping of charge carriers, around the Fermi level of the PANI film at the PANI-insulator interface. This process is thermally activated with a field and doping dependent activation energy in the range of 0.1 to 0.5 eV. Thus, this new technique provides detailed information about charge-carrier dynamics in the space-charge region of the PANI film, at equilibrium. These results have important implications for organic electronics and furthering fundamental understanding of the relationship between doping, disorder and work function in organic semiconductors.

Polyaniline/Gold Nanocomposites J. Anthony Smith 141 Pages Directed by Dr. Ji and #345;?anata The expectation that it is possible to create a range of new materials from two basic components, polyaniline fibers and gold particles is explored. Three synthetic methods were employed each of which created different materials and required different investigation techniques. The methods are: chemical, one step aniline oxidation / AuCl4- reduction; electrochemical/chemical, a two-step composite growth achieved by electrochemical polyaniline thin film growth followed by film immersion in AuCl4- solution and spontaneous reduction to gold particles; electrochemical, resulting in freestanding polyaniline thin film/Au nanoparticles carried out by electrochemical stripping of a polyaniline thin film grown over a sacrificial gold layer in the presence halide solutions. The incorporation of particles was shown to affect film morphology and electrical properties in all synthetic methods. The changes are in large part attributed to the development of a contact potential between the polyaniline and the gold particles. Applications for the composites include use as chemically sensitive layers, corrosion inhibition materials, and use as probes to evaluate nanoparticle substrate interactions.

Since the discovery of the photovoltaic effect in bulk heterojunction devices¡Mthe considerable publications in PSCs have been reported¡OPSCs based on the concept of bulk heterojunction (BHJ) configuration where active layer comprises of a p-type donor (conjugated polymer) and a n-type acceptor (fullerene derivative) materials¡Mrepresents the most useful strategy to maximize the internal donor-acceptor interface area allowing for efficient charge separation¡OTo further enhance the power conversion efficiency from solar cells made of poly(3-hexylthiophene)/[6,6]-phenyl C61 butyric acid methyl ester (P3HT/PCBM) ¡M a new conducting polymer with optimized band energy levels are demonstrated to be one of the key properties¡OIn this study¡MI synthesized a soluble and strongly visible-light absorbing alternating conducting polymer using Suzuki coupling polymerization method¡OThe UV-Vis absorption spectra of copolymer contains an intramolecular charge transfer (ICT) transition band¡Mwhich leads to absorption extending to near-infrared region and optical band gaps is 1.55 eV¡OThe photo-electron spectroscopy in air(PESA) measurements show that the HOMO level of the polymer is ~5.0eV which is lower than P3HT¡O

This thesis studied on the research of how conducting polymer polyaniline can be used in the buffer layer of organic solar cell. There are two methods used.¡]1¡^Using spin-coating to make film of polyaniline solution.¡]2¡^Polymerizing aniline on the substrate directly by electrochemical polymerization. The electrochemical method is separated into cyclic voltammetry and potentiostatic method respectively. The latter method which improved the disadvantage of infractable thick film and low electric conductivity of polyaniline for spin-coating is chosen as the preparation method for polyaniline films. We discuss of the photoelectric characteristics and surface morphologies of polyaniline film and to make a solar cell base on Poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester measured with AM 1.5G 100 mW/cm2 solar light simulation. This research combine above-mentioned results to use potentiostatic method to polymerize polyaniline on the PEDOT¡GPSS into a compound electrode and to replace currently popular ITO positive pole in a organic solar component. The structure is PEDOT¡GPSS/PANI/P3HT¡GPCBM/Al. By electroplating polyaniline, it can enhance the electric conductivity of the film of PEDOT¡GPSS from 1 S/cm to 154 S/cm, furthermore, to reach 1.06% of photoelectric conversion efficiency and creates a new possibility of preparing a flexible organic solar cell.

Polymerization reaction is carried out by the reaction of 2,4,6 trichlorophenol with sodium hydroxide, in the presence of small amount of water by microwave initiation. Synthesis of polymers were successfully performed under microwave enegy. The use of microwave energy was due to advantages of shorter processing time. The main focus of attention was the 90 to 600 watt microwave energy. Polymerizations were performed with different time intervals by keeping the microwave energy and water content constant / or with different energy levels by keeping the time interval and water content constant / or by varying the amount of water by keeping the time and energy level constant.Beside poly(dichlorophenylene oxide), conducting polymer, ion-radical polymer, crosslinked polymer were also be successfully synthesized and characterized. Characterizations of the products were performed by FTIR, 1H-NMR, 13C-NMR, DSC, TGA and elemental analysis. Molecular weight distribution was measured by PL-GPC 220 Polymer Laboratories Instrument. Conductivity measurements were performed by four probe technique.

The synthesis of black conducting polymer (CP) and/or crosslinked polymers (CLP) and/or radical ion polymer (RIP) and/or white polymers (WP) and/or orange polymer (OP) were achieved by using KOH with TCP, pyrrole and thiophene via microwave energy in a very short time interval. Polymerizations were carried out by constant microwave energy with different time intervals varying from 1 to 25 min / or at constant time intervals with variation of microwave energy from 90 to 900 watt / or varying the water content from 0, 0.5 to 5 ml at constant time intervals and microwave energy, or at constant time interval, water content, microwave energy with variation of amount of KOH 0.03 mol to 6x10-4 mol. The effects of heating time, microwave energy, water content and amount of KOH on the percent conversion and the polymer synthesis were also investigated.White, orange polymers and radical ion polymers were characterized by FTIR (Fourier Transform Infrared), 1H-NMR (Proton Nuclear Magnetic Resonance), 13C-NMR (Carbon-13 Nuclear Magnetic Resonance), TGA/ FTIR (Thermal Gravimetric Analysis / Fourier Transform Infrared), DSC (Differential Scanning Calorimeter), SEM (Scanning Electron Microscope), ESR (Electron Spin Resonance), GPC (Gel Permeation Chromatography), UV-Vis (UV-Visible Spectroscopy) and Light Scattering. Conducting and crosslinked polymers were characterized by FTIR, TGA/ FTIR, DSC, SEM, ESR, XRD (Powder Diffraction X-Ray) and conductivity.

A proven strategy, donor-acceptor approach, to reduce the band gap of conjugated materials and possibly improve the photocurrent is to incorporate electron-rich and electron-deficient units in an alternating fashion in a polymer chain. For this purpose, a wise selection of donor and acceptor moieties in a monomer structure results in desired finishing properties of polymeric materials. In this study, fourteen novel monomers were synthesized to explore the acceptor and donor effects on the electronic and optoelectronic properties. Dibenzophenazine, dibenzopyrido]quinoxaline, tetrahydro- dibenzophenazine, thiadiazoloquinoxaline, pyrazinoquinoxaline, thienopyrazine, benzoselenadiazole, thienoselenadiazole were used as acceptor moieties, while thiophene, 3-hexylthiophene and 2,3-dihydrothienodioxine (EDOT) were used as the donor components in these donor-acceptor molecules. To synthesize desired monomers, well-known synthetic methods were performed, including bromination, nitration, reduction and condensation. Bromination was achieved by two different ways depends on the aim, NBS and Br2/HBr medium. For the nitration, HNO2 and H2SO4 were used together. Fe metal in refluxing acetic acid was used as the reducing agent in case of nitro group reductions. On the other hand, Zn metal/AcOH system was chosen for the reduction of both nitro groups and thiadiazole structure to amine, simultaneously. Finally, the Stille Coupling was used to obtain resulting acceptor-donor-acceptor monomers. These synthesized monomers were polymerized by electrochemically and investigated their properties by methods such as spectroelectrochemistry, kinetic and colorimetry studies. Spectroelectrochemistry experiments were performed in order to investigate key properties of conducting polymers such as band gap, maximum absorption wavelength, the intergap states that upon doping and evolution of polaron and bipolaron bands. Switching time and optical contrast of the polymers were evaluated via kinetic studies.