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1
Smith, Jon Anthony. "Polyaniline Gold Nanocomposites." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/4900.
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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.
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Wang, Weining. "Electronic transport in polyaniline films and polyaniline/silicon heterostructure solar cellsWeining." Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2008. http://wwwlib.umi.com/cr/syr/main.
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Abbas, Zaid Kahtan. "Intrinsically conducting polyaniline blends." Thesis, Kingston University, 2009. http://eprints.kingston.ac.uk/20400/.
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The project involved the production of, conductive polyanilines and their blending with elastomers to make new conducting' rubbers. Conductive elastomers already have commercial applications such as antistatic coatings, artificial muscles, sensors and electromagnetic screening. These have been based on carbon black or metal fillers, or more recently conducting polymer powders incorporated into natural or synthetic rubbers. A number of polyaniline-rubber blends have been reported in the literature. A key aim of this project was to improve the compatibility, mechanical, thermal stability and electrical properties of this type of blend through different mixing methods such as solution and thermo-mechanical with more systematic mixing procedures and better optimised mixing conditions. The first part of the work was to optimise the synthesis of conducting polyanilines (P Ani), polyanisidines (poAnis), and copolymers of the latter two, in the presence of a variety of protonating agents under a range of conditions, in order to study the influence of the synthetic conditions on the physical, chemical and morphological characteristics of the polymers. PAnilPoAnis products were prepared via solution polymerisation (simple oxidation at low pH) or via emulsion polymerisation using sulfonic acids (surfactants). Syntheses yielded the emeraldine salts (ES), which were either kept as such, or deprotonated using ammonia solution. There were noticeable differences in the behaviour of the two families of polymers. P Anis display better conductivity and a higher thermal stability than PoAnis due to their less hindered structure. These differences in physical characteristics tend to fade when the compounds are synthesised using a protonic surfactant such as dodecylbenzenesulfonic acid (DBSA). Here, the surfactant-induced order of the final polymeric particles becomes dominant over that of the pendant methoxy-group of PoAnis. Scanning electron microscopy (SEM) revealed the strong influence of the protonic acid used for the synthesis onthe shapes of the final particles. Hence, P Ani-DB SA has a monoclinic appearance and rhombic shape particles while P Ani-ß-naphthalenesulfonic acid (ß-NSA) has a "flakey" morphology. It was shown that a very small quantity of co-monomer could change drastically the physical characteristics of P Ani; hence, when anisidine (Anis) is added to the aniline-acid complex, a different crystalline structure is achieved. The chosen polymer (P Ani-DB SA) was matched with two individual elastomers, one based on an ethylene oxide co-polymer and the other on a nitrile butadiene co-polymer, both of which had suitable solubility parameters. The polymers were solution-blended and studied for compatibility by means of microscopy, electrical conductivity measurements and thermal analysis. Blends of poly (epichlorohydrin-co-ethylene oxide) rubber (Zeon Hydrin" C2000L) and polyaniline doped with dodecylbenzenesulfonic acid (P Ani-DB SA), containing different weight fractions of P Ani, were cast from solution. Solubility parameters for both P Ani¬DBSA and Hydrin® were calculated and found to be comparable, favouring some degree of miscibility. Conductive transparent films were formed by casting onto PTFE substrates. Conductivities of the cast films were found to be in the region of 10-7 Scm" for 1 wt% P Ani¬DBSA. Electrical conductivities increased with the proportion of P Ani-DB SA, showing a percolation threshold as low as I wt%, with highest conductivity achieved at, 50wt%. Decomposition steps of conductive blends were investigated using thermogravimetric analysis (TOA) and differential scanning calorimetry (DSC). The thermal stability of the blends was influenced by the ratio ofPAni-DBSA to Hydrin'". The effect of composition on the glass transition in the blends was determined using thermomechanical analysis (TMA). Thin films of the blends of dodecylbenzenesulfonic acid (DB SA) doped polyaniline (P Ani) and pure grade of Poly[(acrylonitrile-co-butadiene)/poly vinylchloride] (Zeon Nipol® DN171) were prepared via co-dissolution, at varying ratios of conducting filler (0.5-50)wt %. The electrical conductivity correlated with the concentration ofP Ani-DB SA. At a percolation threshold ofO.9% (wt/wt), an increase in electrical conductivity of approximately eight orders of magnitude was observed, with a recorded conductivity of 1.21xlO-4 S.cm-1 for the most conductive blend (consisting of 50wt% PAni). Characterisation by UV-visible spectroscopy indicated the retention of the doped state of the conductive P Ani-DB SA in each elastomer blend. Morphological studies by optical microscopy, showed the presence of P Ani-DB SA agglomerate networks (or interpenetrating networks) at higher concentrations; however, at lower concentrations of P Ani-DB SA, the dispersion and encapsulation of the conductive species was observed. Due to the double phase morphology of Nipol® DN 171, the encapsulating phenomenon was attributed to the presence of the thermoplastic (poly vinylchloride). Solubility parameter calculations confirmed the compatibility ofP Ani-DB SA with the constituents of the Nípol" DN171 elastomer. This was supported by the infrared spectrum, which shows the presence of functional groups specific to the reacting components of each blend. Thermal studies, performed by DSC and TOA, indicated an increased thermal stability with increasing concentration of the elastomer.
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Gill, Michael. "Polyaniline-silica colloidal nanocomposites." Thesis, University of Sussex, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239632.
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The work presented in this thesis provides a new route to a colloidal form of polyaniline, which uses colloidal silica as a dispersant. We obtained stable colloidal dispersions of polyaniline-silica composite particles with a 'raspberry' morphology. Compressed pellets of these particles exhibit solid-state conductivities of 1O-!_10-2 S crrr l, which is approximately 1-2 orders of magnitude lower than that of polyaniline bulk powder. This novel colloidal form of polyaniline has significantly improved processability compared to conventionally synthesised polyaniline. The synthesis and chemical characterisations are presented for various polyaniline-silica colloidal nanocomposites. The quantity of polyaniline incorporated into the nanocomposite particles can be controlled by varying the diameter of the silica dispersant, approximately 20% and 60 % polyaniline content being obtained using 120 nm and 10 nm diameter silica respectively. The average particle size ranges of nanocomposites was found to be 150 to 700 nm and 330 to 560 nm, as determined by transmission electron microscopy (TEM) and disc centrifuge photosedimentometry (DCP) respectively. The nanomorphology and surface composition of the polyanilinesilica particles were determined by small angle X-ray scattering (SAXS) and X-ray photoelectron spectroscopy (XPS) respectively. The average inter-particle separation distance of the silica particles within the polyaniline-silica raspberries was determined by SAXS to be 4 nm, a dimension equivalent to molecular polyaniline. The XPS data suggests that the surface of the particles is silica rich, this is consistant with their long term colloidal stability in 1.2 mole dm-3 HCl. The kinetics of polymerisation was studied using 1H NMR spectroscopy to monitor the disappearance of aniline monomer. Polymerisation rates during the synthesis of polyaniline-silica nanocomposites were appreciably faster than the corresponding precipitation polymerisations carried out in the absence of silica dispersants, due primarily to an increase in the second auto-catalytic step of the reaction. Rate constants were determined for both these types of synthesis; the values obtained for the precipitation polymerisations were in reasonably good agreement with literature values.
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Focke, Walter Wilhelm. "Conduction mechanisms in polyaniline." Thesis, Massachusetts Institute of Technology, 1987. http://hdl.handle.net/1721.1/14642.
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Jonke, Alex P. "Atomic metal/polyaniline composites." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/49070.
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It is ideal to theoretically predict the activity of a catalyst. It has been recognized that not only the type of metal, but also its atomic size plays an important role in catalysis. In the past, atomic clusters have been created by sputtering from a sacrificial metal plate and then using a mass selector to choose cluster sizes from 1-233 atoms of gold. This approach has practical limitations. In this thesis, I describe a procedure by which atomic clusters of gold containing 1-8 atoms are deposited in polyaniline as an isolation matrix. My atomic deposition follows a cyclic pathway. Atomic clusters of palladium and atomic alloys of gold and palladium are also deposited in polyaniline using the same process. It is to show that this method will also work for other metals. These composite materials are characterized, and the catalytic activity for alcohol oxidation is evaluated.
This thesis is divided into seven chapters. The first chapter discusses the chemistry of polyaniline for using gold and palladium as catalysts. The technique developed to deposit the atomic clusters is discussed in the second chapter. This technique deposits one atom of metal per imine site on polyaniline, per cycle. The cycle is repeated n-times until a cluster of specified size, Mn, and composition has been synthesized. It is known that polyaniline plays an important role in stabilization of the formed clusters which prevents their aggregation. The optimization of this technique is the topic of the third chapter along with the description of how these composite films are produced. To end this chapter, the composite films are characterized by cyclic voltammetry, Kelvin probe, and X-ray photoelectron spectroscopy.
In chapters 4 and 5, the catalytic activity of the polyaniline/gold composites for the oxidation of alcohols in alkaline media using cyclic voltammetry is evaluated. In chapter 4, the correlation of the electrochemical activity for the oxidation of n-PrOH with the odd-even pattern from the calculated HOMO-LUMO gap energies for the same size clusters is shown. It is shown that the infrared spectrum of polyaniline with different sizes of atomic gold clusters also follows the odd-even pattern. Chapter 5 expands on the discussion of the catalytic oxidation of alcohols. The oxidation of methanol, ethanol, propanol, and butanol is surveyed. The peak currents are again dominated by the odd-even pattern.
In chapter 6, the versatility of the atomic deposition cycle is shown by depositing atomic palladium clusters. The peak currents for the oxidation of n-PrOH by these palladium composite films again follows the predicted pattern of the calculated HOMO-LUMO gap energies for atomic palladium clusters. This chapter also explores bimetallic atomic clusters of gold and palladium. The results indicate that the catalytic activity depends on the orientation of the cluster in the polyaniline matrix. Chapter 7 discusses the oxidation of methanol, ethanol, and isopropanol on AunPd1 bimetallic atomic clusters. The addition of palladium in the cluster increases the peak current densities for the oxidation of both alcohols except for the most stable of the atomic gold clusters, while it inactivated the electrodes for isopropanol. The possible future work for this project is discussed in chapter 8.
Overall, this thesis has developed a novel and unique technique for depositing atomic metal clusters into a polyaniline matrix. The technique is versatile enough to deposit atomic metal clusters other than gold, as shown by creating atomic palladium clusters and atomic bimetallic clusters of gold and palladium. This is extremely useful, since this single technique can produce many different types of atomic catalysts. The composite materials have been shown to be catalytically active for the oxidation of alcohols in alkaline media. This indicates a significant improvement to conserve precious metals while still retaining a high catalytic activity.
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Milton, A. J. "Structural properties of polyaniline films." Thesis, Durham University, 1993. http://etheses.dur.ac.uk/5548/.
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This thesis describes the experimental investigations of the structural properties of the conductive polymer, poly aniline. These studies have been performed on free-standing film samples, solution cast using the solvent N- methyl-2-pyrrolidinone (NMP). Such specimens have enabled a wealth of detailed information about polyaniline to be derived. The polymer itself was synthesised in the emeraldine base form using a chemical route optimised at Durham. The product was then assessed for its chemical structure and molecular weight using (^13)c NMR, elemental analysis and gel permeation chromatography. The process of fabricating the polymer into free-standing films is discussed and assessed. It has been shown that such films may be oriented by the application of uniaxial stress at elevated temperatures and this procedure has been described and analysed in detail. This stretching process aligns the polymer chains on a molecular level and hence produces changes in the physical properties of films. In particular, upon doping to the conducting emeraldine salt form by protonation in aqueous HCl, stretch oriented films display a remarkable increase in conductivity (parallel to the stretch direction) over their unstretched, doped counterparts. Various thermal analysis techniques, including dynamic mechanical thermal analysis, dielectric thermal analysis, thermomechanical analysis and infrared spectroscopy have been used to probe the physical properties of polyaniline films. Using these techniques a number of important thermal transitions have been observed and furthermore the stretch alignment process has been rationalised. Infrared orientational analysis has revealed detailed information about the molecular orientation produced during macroscopic stretching of a film. The type and degree of chain orientation has been analysed as well as the geometrical structure of a single chain. X-ray diffraction has probed the crystalline fraction of polyaniline films. Various aspects concerning the crystalline fraction of film samples has been derived along with an orientational analysis which has been contrasted with the infrared results. An even greater amount of structural information has been revealed by neutron diffraction and this technique has enabled a detailed examination of the structure of the crystalline phases of polyaniline to be made.
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Deng, Chengming. "Synthesis and Characterization of Polyaniline." University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1603712965215724.
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Ginder, John Matthew. "Electronic defect states in polyaniline." The Ohio State University, 1988. http://rave.ohiolink.edu/etdc/view?acc_num=osu1343059710.
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Sebantu, Lambert. "Electrochemistry of polyaniline-DNA system." [Johnson City, Tenn. : East Tennessee State University], 2004. https://dc.etsu.edu/etd/895.
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Thesis (M.S.)--East Tennessee State University, 2004.<br>Title from electronic submission form. ETSU ETD database URN: etd-0331104-130134. Includes bibliographical references. Also available via Internet at the UMI web site.
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SHAH, KUNAL G. "SYNTHESIS AND CHARACTERIZATION OF POLYANILINE,SUBSTITUTED POLYNAILINES AND THEIR COMPOSITES COATINGS ON AL-2024." University of Cincinnati / OhioLINK, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1004469624.
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Al, Zohbi Fatima. "Etude de Polyanilines et de nanocomposites Polyaniline/Graphène en milieu liquide ionique protique pour la réalisation de supercondensateurs." Thesis, Tours, 2016. http://www.theses.fr/2016TOUR4026/document.
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Les travaux réalisés dans le cadre de cette thèse ont porté sur la réalisation de polymères conducteurs de type polyaniline et de leurs composites associés à du graphène en vue d’une utilisation en tant que matériaux d’électrodes dans des dispositifs de stockage d’énergie de type supercondensateurs. Les travaux se sont tout d’abord orientés sur la synthèse de nouveaux liquides ioniques protiques (LIP) associant des cations pyrrolidinium (Pyrr+) et imidazolium (Imi+) avec des anions p-toluène sulfonate (PTS-), hydrogénosulfate (HSO4-) ou (+)-camphre-10-sulfonate (Cs-), et de l’étude de leur propriétés physico-chimiques (conductivité, viscosité) dans des mélanges binaires LIP/eau. Après avoir déterminé les formulations permettant d’atteindre les propriétés de transport optimales, les capacitances spécifiques de la Pani/HCl dans ces milieux LIP ont été déterminées et nous avons montré que les performances de dispositifs symétriques sont améliorées en capacitance, énergie et en puissance (400 F/g, 7 Wh.kg-1 et 4 kW.kg-1 pour les valeurs les plus élevées) par rapport à un milieu H2SO4 1M. Ces milieux LIP ont également été utilisés comme milieu de synthèse de la Pani. Nous avons ainsi montré que la nature des LIP, qui sont des milieux nanostructurants, pouvait modifier les propriétés électroniques, morphologiques et thermiques des Pani. Un optimum de conductivité électronique de la Pani (22 S/cm) a été atteint avec une synthèse réalisée dans le mélange binaire [Imi][HSO4]/eau 70/30 (pourcentage massique) générant une morphologie fibrillaire et une bonne cyclabilité (93% de rétention de capacitance sur 1000 cycles dans H2SO4 1M. Des valeurs de près de 400 F/g ont été obtenues dans le mélange [Pyrr][HSO4]/eau 41/59 optimisé. Dans le cas de la synthèse de la Pani réalisée dans [Pyrr][PTS]/eau, un gain en stabilité thermique (360°C) est obtenu grâce au dopage par l’anion PTS-. Finalement, une étude exploratoire sur la préparation de composites Pani/graphène et Pani/oxyde de graphène a été réalisée. Les synthèses des nanocomposites ont été effectuées dans les mélanges LIP/eau. L’optimisation de la composition du composite a été étudiée et indique que des rapports massiques de graphène ou oxyde de graphène d’environ 15% permettent d’atteindre des performances de stockage prometteuses et exaltées par rapport à celles obtenues pour des Pani sans graphène<br>The work carried out during this PhD thesis is based on the preparation of conducting polymers such as polyaniline (Pani) and their composites associated with graphene for use as electrode materials for supercapacitors application. This work was first dedicated to the synthesis of new protic ionic liquids (PILs) combining pyrrolidinium (Pyrr+) or imidazolium (Imi+) cations with p-toluene sulfonate (PTS-), hydrogen sulfate (HSO4-) or (+)-camphor-10-sulfonate (Cs-) anion, and the study of their physico-chemicals properties (conductivity, viscosity) in binary mixtures PILs/water. After determining the formulations needed to achieve the optimum of transport properties, the specific capacitance of Pani/HCl in these PILs medium was determined, and we have shown that the performance of symmetrical devices are improved in capacitance, specific energy and specific power (400F/g, 7Wh/kg and 4kW/kg for the higher values) in comparison to those obtained in a H2SO4 1M medium. These PILs mediums were also used as a synthesis medium of Pani. We have shown that the nature of PILs, acting as soft template, could change the electronic, morphological and thermal properties of Pani. An optimum of electronic conductivity of Pani (22 S/cm) was obtained with a synthesis realized in the binary mixture [Imi][HSO4]/water 70/30 generating a fibrillar morphology and a good cyclability (93% capacitance retention over 1000 cycles in H2SO4 1M at 2 A/g). For Pani synthesis in [Pyrr][PTS]/water, a thermal stability gain (360 °C) is obtained thanks to a PTS- doped Pani. Finally, a preliminary study on the preparation of composite Pani/graphene and Pani/graphene oxide was performed. The syntheses of nanocomposites were realized in PILs/water mixtures. The optimization of the composition of the Pani nanocomposites was studied and it was found that a mass ratio of about 15% in weight of graphene or graphene oxide enables to obtain promising nanomaterials with higher electrochemical performances compared with pristine Pani
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PADILLA, RONALD MARCOS ARCOS. "STUDY OF TRANSPORT OF POLYMER POLYANILINE." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2011. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=18472@1.
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COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR<br>O desenvolvimento de materiais com propriedades elétricas incomuns,
como é o caso dos polímeros condutores, vem sendo estudado por muito tempo.
Este tipo de sistema orgânico apresenta característica isolante pura, mas quando
são introduzidas impurezas por meio da dopagem variam a sua condutividade de
forma significativa em comparação com os metais.
No presente trabalho, investigamos o transporte de carga eletrônica no
sistema molecular do polímero Polianilina (PAN), através de cálculos quânticos
mediante o método de Hückel e acoplado com a metodologia das funções de
Green de não equilíbrio (FGNE) foram obtidas expressões para a condutância e
densidade local de estados (LDOS). Realiza-se o estudo da estrutura eletrônica
da PAN conformada de 200 anéis apresentando algum tipo de defeito estrutural
tipo polaron o bipolaron onde os efeitos provocados pela desordem
desempenham um papel fundamental.
Investigamos assim a LDOS e a condutância para formações de cadeias de
PAN tanto protonadas e não protonadas, verificando assim que a rede
bipolarônica presente na estrutura do sistema apresenta um deslocamento da
energia de Fermi para dentro da banda de valência, região de estados
espacialmente estendidos onde a condutância é finita, comprovando assim a
transição metal-isolante para este material.<br>The development of materials with unusual electrical properties as is the
case of conducting polymers has been studied for a long time. This type of
organic system provides insulation characteristic pure, but when impurities are
introduced by doping the conductivity varies significantly in comparison with
metals.
In this study, we investigated the transport of electronic charge in the system
polymer molecular Polyaniline (PAN) through quantum calculations by the
Hückel method and coupled with the methodology of Green functions of nonequilibrium
(FGNE) were obtained expressions for the conductance and local
density of states (LDOS). Is carried out to study the electronic structure of PAN
conformed to 200 rings showing some type of structural defect type polaron
bipolaron where the effects of the disorder play a key role.
Thus investigated the LDOS and conductance to PAN formation of chains of
both protonated and non protonated, thus verifying that the structure of the
bipolaron in this system has a displacement of the Fermi energy into the valence
band region of spatially extended states where conductance is finite, thus
proving the metal-insulator transition for this material.
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Kim, Kwangjoon. "Dynamics of photoexcited states in polyaniline." The Ohio State University, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=osu1343060920.
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Long, Stephen M. "Structure of defect states in polyaniline." The Ohio State University, 1995. http://rave.ohiolink.edu/etdc/view?acc_num=osu1343061764.
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Menardo, Christine. "La polyaniline : propriétés magnétiques et conductivité." Grenoble 1, 1989. http://www.theses.fr/1989GRE10099.
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Preparation, etude par rmn #1#3c, dosage acido-basique, rpe, squid, de la polyaniline en relation avec les transitions isolant conducteur du polymere. Mecanisme de conduction par des bipolarons. Comparaison des proprietes de la polyaniline et de la poly(n-methyl aniline): role des sites imines protones de la polyaniline dans la conductivite
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Baker, M. Christina Opimo. "Applications of polyaniline nanofibers and nanocomposites." Diss., Restricted to subscribing institutions, 2008. http://proquest.umi.com/pqdweb?did=1666392621&sid=19&Fmt=2&clientId=1564&RQT=309&VName=PQD.
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Chiou, Nan-Rong. "Aligned and oriented polyaniline nanofibers: frabrication and applications." The Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=osu1148485692.
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Lennartz, Werner. "Strukturuntersuchungen an intrinsisch leitfähigen Polyanilin-, PMMA-Blends SAXS als Messverfahren zur Bestimmung der Morphologie synthetischer Metalle /." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=970154267.
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Tian, Shengjun. "Thin functional conducting polymer films preparation, properties and applications /." [S.l. : s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=975929003.
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Jameel, Dler Adil. "Electrical properties of sulfonated polyaniline (Span) and polyaniline (Pani) polymers grown on conventional and high index GaAs substrates." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/36040/.
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The electrical properties of sulfonated polyaniline (SPAN) and polyaniline (PANI) grown on both conventional (100) and high Miller index GaAs surfaces are investigated. These devices were electrically characterized using Current-Voltage (I-V), Capacitance-Voltage (C-V), Capacitance-Frequency (C-F), Capacitance-Conductance-Frequency (C-G-F), Deep Level Transient Spectroscopy (DLTS), and Laplace DLTS measurements in the temperature range 20 – 440 K. Electrically active defects are generated at/near the interface and away from the interface with energy levels deep in the bandgap of the materials. These defects considerably affect the electrical and optical properties of the devices. This thesis reports the effect of n-type GaAs substrate orientation, namely (100), (311)A and (311)B, on the electrical properties of sulfonated polyaniline (SPAN)/GaAs heterojunction devices. It was found that the interface state density (Dit) of SPAN/(311)B GaAs samples is lower than that of (100) and (311)A GaAs devices. This behaviour is attributed to the effect of crystallographic orientation of the substrates, and was confirmed by DLTS results as well. In addition, the inhomogeneity of the interface between various GaAs substrates and SPAN is investigated in terms of barrier height and ideality factor by performing I–V measurements at different temperatures (20–420 K). The I–V results indicate that the value of the rectification ratio (IF/IR) at 0.5 V is higher for SPAN/(311)B GaAs samples than for SPAN/(100) GaAs and SPAN/(311)A GaAs samples. Moreover, the barrier height decreases and the ideality factor increases with decreasing temperature for all three heterostructure devices. This thesis also reports an extensive study of the electrical properties of PANI/GaAs (organic-inorganic) hybrid heterojunctions. Polyaniline (PANI) thin films were deposited by a very simple technique on (100), (311)A and (311)B ntype Gallium Arsenide (GaAs) substrates to fabricate hybrid devices with excellent electrical properties. The DLTS and Laplace DLTS measurements illustrated that the number of defects at/very close to the interface region in PANI/(311)A GaAs samples is lower than those of PANI/(100) GaAs and PANI/(311)B GaAs samples. Moreover, the analysis of I–V characteristics based on the thermionic emission mechanism has shown a decrease of the barrier height and an increase of the ideality factor at lower temperatures for all the three hybrid devices. The interface states were analysed by series resistance obtained using the C–G–V methods. The interface state density (Dit) of PANI/(100) GaAs devices is approximately one and two order of magnitude higher than that of PANI/(311)B GaAs and PANI/(311)A GaAs devices, respectively. Additionally, the devices show excellent air stability, with rectification ratio values almost unaltered after two years of storage under ambient conditions, making the polyaniline an interesting conductor polymer for future devices applications.
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Yilmaz, Faris Sad. "Polyaniline: Synthesis, Characterization, Solution Properties, And Composites." Phd thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/3/12608598/index.pdf.
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Polyaniline was chemically synthesized at three different temperatures of 25, 0, and -25oC, by oxidative polymerization with ammonium peroxidisulfate at equimolar of aniline to oxidant ratio and 1M HCl. The resulted polyaniline was in a powder form which was characterized by several techniques such as: electrical conductivity, elemental analysis, thermal analysis, wide-angle X-Ray diffraction, and scanning electron microscope. The solution properties of the reduced polymer were studied by viscometry, static and dynamic light scattering.
It was found that as the polymerization temperature decreased, the molecular weight, crystallinity, and thermal stability of polyaniline increased, while the electrical conductivity was independent of the polymerization temperature. Moreover, the morphology of the polymer was changed from granular to tubular with reducing polymerization temperature. Viscometry and static light scattering showed that polyaniline has a flexible random coil conformation when dissolved in N-methyl-2-pyrrolidinone which proved to be a good solvent for this polymer. Dynamic light scattering indicated that the polymer solution is a polyelectrolyte with high hydrodynamic radius at low polymer concentrations.
All mechanical features except Young'<br>s modulus of polyaniline-filled low density polyethylene composites became poorer as polyaniline content increased. Moreover, a sudden increase in the electrical conductivity with increasing polyaniline contents was also observed.
The conductivity of the tubular composites of multi wall nanotubes (MWNTs)-filled polyaniline increased with increasing MWNTs loading, and became weakly temperature dependent. The morphological analysis indicated that the MWNTs were well dispersed and isolated, and the tubes became crowded proportionally to MWNTs weight percent used in the composites.
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West, Ryan Matthew. "Work function fluctuation analysis of polyaniline films." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/47586.
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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.
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Ou, Runqing. "Nondestructive characterization of polyaniline emeraldine base films." Thesis, Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/9143.
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Monkman, Andrew Paul. "The characterisation of the conducting polymer polyaniline." Thesis, Queen Mary, University of London, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363035.
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Tzamalis, Georgios. "Optical and transport properties of polyaniline films." Thesis, Durham University, 2002. http://etheses.dur.ac.uk/4148/.
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This thesis presents the results of a comprehensive study on the transport and optical properties of polyaniline (PANI) films. The films are derived by protonation (doping) of the emeraldine base form of polyaniline, as synthesized in Durham, with either 2-acrylamido-2-methyl-l-propanesulfonic acid (AMPSA) or 10- camphorsulfonic acid. Thus, two distinct PANI systems are obtained: PANI-CSA and PANI-AMPSA. The variation of the doping level can affect the metallic properties of the final system, so that samples close to the boundary as well as samples at either side of a disorder induced metal-insulator can be obtained. The relation between the doping level and the degree of disorder, along with the existence of an inherently metallic behaviour in PANI, are investigated through a series of experiments. Temperature dependent dc conductivity measurements ranging from 10-295 K are performed using a closed loop helium cryostat under dynamic vacuum (~10(^-5) mbar). From the conductivity data curves, typical fingerprints of the metallic behaviour are detected for certain samples and an initial estimate of the degree of disorder is implicitly attained. More specific information regarding the microscopic contributions to the transport mechanisms is obtained via low temperature (down to 1.5 K) magnetocon- ductance measurements on selected samples. The magnetic field dependence of conductivity for fields up to 14 T is measured and the suitability of the localization- interaction model for the understanding of the transport mechanism in PANI is examined. Infrared reflectivity (20-9000 cm(^-1)) measurements on samples of both PANI systems are performed. The experimental configuration permits the determination of the sample’s absolute reflectivity. The optical constants are deduced from Kramers- Kronig analysis of the reflectivity data. Typical features of metallic behaviour are examined and analysed in the context of the localization modified Drude model. The results are shown to be consistent with the transport measurements, indicating that PANI is a disordered metal close to the boundary of a disorder induced metal- insulator transition.
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Shaw, Tiana C. "Preparation of Derivatized Polyaniline for Biosensing Applications." DigitalCommons@Robert W. Woodruff Library, Atlanta University Center, 2016. http://digitalcommons.auctr.edu/cauetds/54.
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Conducting polymers have emerged as a promising material for optoelectronics and chemical sensing application. Polyaniline (PANI) is a conductive polymer which can be easily functionalized to be specific for various biomolecules and has ideal sensor characteristics. The protonation and deprotonation of the polyaniline’s backbone by derivatization can result in color and conductive change responses. This makes it ideal for the construction of a real time, naked eye sensor. Derivatized polyaniline has previously been reported as a colorimetric sensor in solution. We plan to create a more practical sensor by synthesizing hydroxyl functionalized polyaniline thin films. In this study, we designed a process to functionalize polyaniline and deposit it as a thin film on quartz or silicon substrate via a dip coating process. To demonstrate the use of derivatized PANI in biosensing applications, derivatized and underivatized PANI thin films were treated with solutions of L-aspartic (Asp) acid at concentrations ranging from 10-8 mM to 103 mM and monitored utilizing UV-Vis spectroscopy. We found that the derivatized thin films change from deep blue to green color upon addition of Asp solution and showed a decrease in the characteristic quinoid ring peak at 600nm and the appearance of a new polaron peak at 425nm. The underivatized PANI films showed no colorimetric response indicating the hydroxyl functionalized PANI films are a more ideal material for a biosensing and naked eye detection. The polyaniline derivative was characterized using FT-IR spectroscopy, 1H NMR spectroscopy, UV-VIS spectroscopy, and Scanning Electron Microscopy. Additionally, conductivity studies were utilized to explore the material’s effectiveness as an electronic sensor using a 4-point probe to measure resistance.
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Abia, Atogho Jude. "Polyaniline and Its Derivatives for Environmental Analysis." Digital Commons @ East Tennessee State University, 2006. https://dc.etsu.edu/etd/2240.
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Electrooxidation has been used to deposit thin film polyaniline as well as its derivative - thin film poly (ortho-phenylenediamine) (POPD) and poly (meta-phenylenediamine) (PMPD) on carbon electrodes, which are subsequently used to monitor the environmental heavy metal ions (Hg2+, Pb2+ ,Cd2+) through a rather unusual "blocking" of anodic stripping for these metals. Using Hg2+ as a model, its cyclic voltammogram for a modified glassy carbon electrode with the resultant polymer shows an enhanced cathodic peak that increases linearly with the analyte ion concentration. POPD also exhibits unique selective detection for organic species. Acetaminophen and uric acid can be preferentially detected over ascorbic acid from a mixture of these three compounds. In addition, the effect of carbon nanotubes incorporated in polyaniline (PAN) film is observed to have enhanced electrochemical catalytic activities on the remedy of environmental dichromate.
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Brault, Damien. "Synthèse et caractérisations thermoélectriques de polyaniline dopée." Thesis, Tours, 2018. http://www.theses.fr/2018TOUR4032/document.
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Dans le contexte actuel de recherche d’efficacité énergétique, c’est-à-dire de maîtrise de l’énergie incluant la valorisation de l’énergie perdue, ce projet de thèse propose de synthétiser et caractériser les propriétés thermoélectriques de la polyaniline dopée. Nous avons ainsi synthétisé plusieurs échantillons de polyaniline et étudié l’influence des conditions de synthèse, du taux de dopage, du type de dopant, du taux de cristallinité ou de la mise en forme du matériau fini sur leurs propriétés thermoélectriques. Tout d’abord, nous avons mesuré les dépendances en température des conductivités électriques et thermiques ainsi que du coefficient Seebeck de la polyaniline dopée à l’acide chlorhydrique (Pani/HCl). Nous avons montré que lors de la synthèse, une température de polymérisation basse (223K) permet d’obtenir de meilleures conductivités électriques et donc des propriétés thermoélectriques améliorées. D’autre part, la valeur de la pression utilisée pour compresser le matériau et le mettre en forme doit être assez élevée (1.109GPa) pour optimiser les performances thermoélectriques. Afin de mieux comprendre les propriétés de transport de la polyaniline dopée au chlorure, nous nous sommes ensuite intéressés à ses propriétés magnétiques et calorifiques. Les mesures de la susceptibilité magnétique et de la capacité calorifique du polymère dopé en fonction de la température ont ainsi permis de déterminer la nature de ses états électroniques et de déduire le type de transport au sein du polymère. Enfin, nous avons synthétisé et étudié la polyaniline dopée au camphresulfonate en faisant varier le taux de dopage entre 30% et 90%. Les mesures de conductivités électriques, thermiques et du coefficient Seebeck en fonction de la température montrent qu’un optimum peut être trouvé pour un taux de dopage de 50%<br>In the actual frame of energy efficiency research, namely, the energy management including wasted energy, this PhD project deals with the synthesis and characterization of thermoelectric properties of doped polyaniline. Consequently, polyanilines have been synthesized and the effect of the synthesis conditions, the doping level, the type of dopant, the crystallinity or the sample preparation of the final material on the thermoelectric properties have been studied. Firstly, we measured the thermal dependencies of electrical and thermal conductivities as well as Seebeck coefficient hydrochloric acid doped polyaniline (Pani/HCl). We showed that a low polymerization temperature (223K) lead to better electric conductivity and so improved thermoelectric properties. On the other side, the pressure used to compress powders should as high as 1.109GPa to optimize the thermoelectric performance. Then, in order to have a better understanding of the transport properties of chloride doped polyaniline, we investigate the magnetic and thermal properties. Measurements of the specific heat and the magnetic susceptibility of chloride doped polyaniline as a function of the temperature allowed to determine the electronic states and the mechanism of transport in the polymer chains. Finally, we synthesized and studied camphorsulfonate doped polyaniline by varying the doping level between 30% and 90%. The electrical, thermal conductivities and Seebeck coefficient as a function of the temperature show clearly on optimum of doping level at 50% with camphorsulfonate doping agent
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Muthukumaraswamy, Sivaneswary. "Evaluation of electrochromic materials for displays." Thesis, London South Bank University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367908.
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Gottwald, Tomáš. "Vodivé polymery a jejich využití v superkondenzátorech." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-218316.
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This work deals with the issues of using conducting polymers for supercapacitor electrodes and optimizing the technological process for their production. The work focuses on optimizing the amount of polymer used in order to achieve the most capacity. The methodology consists of creating an appropriate experimental electrode and subsequent measuring its associated capacity with BioLogic. This approach leads to creating charts which show the dependencies of capacity on the amount of polymer used.
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Michaelson, Jeff C. "Polyaniline and related compounds : synthesis, morphology and electrochemistry /." [S.l.] : [s.n.], 1994. http://library.epfl.ch/theses/?nr=1211.
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Chiou, Nan-Rong. "Aligned and oriented polyaniline nanofibers fabrication and applications /." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1148485692.
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Summerour, Jamie Maddox. "Tritium doped polyaniline as a β-irradiation source". Thesis, Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/26962.
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Gupta, Yogesh. "A study of polyaniline membranes for gas separations." Thesis, Loughborough University, 2007. https://dspace.lboro.ac.uk/2134/8003.
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Membrane based gas separations are proven to be technically attractive because of their simplicity and low energy costs, although they are often limited by insufficient flux, selectivity and stability. During the past thirty years, major developments in this technology have been made by developing high flux asymmetric membranes, and large surface area membrane modules. Today, in the present market, the sales of the membrane gas separation equipments have grown to become a $150 million per year business, and substantial growth in the near future is likely. More than 90% of membrane gas separation business involves the separation of non-condensable gases, i.e. nitrogen from air, carbon dioxide from methane, and hydrogen from nitrogen, argon, or methane. However, a large potential market for membrane gas separation lies in refineries. The separations of hydrogen/hydrocarbon and olefin/paraffin are regarded as import processes (although challenging ones) in the petrochemical industry. The membrane based separation p~ocess to sepfirate olefins from paraffins is likely to be developed to the commercial state in the next few years. Industry's demands for increasing the separation effectiveness and productivity have encouraged conducting research into development of new membrane materials. Polyaniline is regarded as so far the best alternative for gas separations, since the molecular spacing of polymer chains can be controlled by its interesting doping/dedoping chemistry. A novel method to make reproducible defect-free dense self-supported polyaniline films with the thicknesses between 2 and 6 IJm, and polyaniline nanofilm membranes with selective polyaniline layer thicknesses between 300 and 800 nm supported on a porous polyvinylidene fluoride (PVDF) substrate is developed. (Continues...).
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Pan, Bo-Hong, and 潘柏宏. "Synthesis of polyaniline gold and polyaniline silver bilayer nanotubes." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/60805822812617525318.
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碩士<br>國立中央大學<br>化學工程與材料工程研究所<br>93<br>Abstract
Polyaniline gold/silver bilayer nanotubes are synthesized by reduction of aqueous HAuCl4 and AgNO3 with polyaniline. Polyaniline nanotubes of uniform size are synthesized inside the channels of anodic alumina membrane. After dissolving anodic alumina with NaOH and polyaniline with NMP, the remaining gold and silver tubes can be obtained. We also synthesized polyaniline palladium bilayer nanotubes by electroless plating of Pd in SnCl2-PdCl2 solution. SEM photographs show the formation of polyaniline gold/silver/palladium bilayer nanotubes. EDX results confirm the formation of metal tubes. TEM photographs show the formation of bilayer tubes and selected area electron diffraction results indicate gold and silver nanotubes grow along the [100]，[110] respectively.
In this study, we also use polycarbonate track-etched membrane as templates to synthesize polyaniline nanotubes. Owing to different characteristics of the two templates, the morphology of the polyaniline tubes synthesized in them are different. Polyaniline tubes firmed in channels of anodic alumina membrane are conform gold, silver and palladium deposited are highly crystalline nanotubes. Polyaniline tubes formed in polycarbonate membrane are not uniform, hence only gold or silver particles are deposited on local areas.
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ju, yu hui, and 游蕙如. "new chical polyaniline." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/18112536780359026850.
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碩士<br>國立清華大學<br>化學系<br>90<br>Abstract
New chiral aniline copolymers containing L-cysteine substituent have been first prepared from unsubstituted polyaniline, utilizing a concurrent reduction and substitution reaction performed in the solid-state matrix of polyaniline.
The chemical, electrical and chiroptical properties of the resultant copolymer powder have been characterized by XPS, ATRIR, CV, UV-vis, CD ( circular dichroism ) spectroscopy. The resultant copolymer powder was found to contain ca. 24 mol % (based on atomic ratio S/(N-S) measured by XPS ) of L-cysteine group and are very conductive (2 S/cm ). XPS spectra of PAN-L-Cys show a newly appeared S 2p line at around 163.6 eV, confirming the formation of the sulfide linkage. The ATRIR spectrum of the resulting aniline copolymer powder clearly showed reduction in the intensities of the peaks associated with diiminoquinoid ring at 1600 cm-1 (C=C stretching vibration of diiminoquinoid ring ). The oxidation potential E0 of the resulting aniline copolymer was lower than that of parent polyaniline. This result is consistent with the expectation that the attachment of electron-donating L-cysteine group that help lower the oxidation potential of polyaniline backbone . The UV-vis spectra of the resulting aniline copolymer showed that the lmax of the p-p* transition band is longer than the corresponding band of the parent unsubstituted polyaniline, possibly due to the enhanced electron density of the copolymer backbone as contributed by the electron-donating L-cysteine group. The corresponding CD spectra for PAN-L-Cys and PAN-D-Cys ( in NMP solutions ) are mirror image of each other, indicating that these two chiral form of polyaniline possess opposite handedness.
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Chiang, Cheng-Hsien, and 江政憲. "Electropolymerization of polyaniline." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/345g6d.
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碩士<br>國立臺北科技大學<br>有機高分子研究所<br>100<br>The research consists of three sections. The first section involves the electropolymerization of aniline under different enviroments. The variables are electrolytes, doping chemicals. The stracture-properties relationships are elucidated.
The second section illustrate the electropolymerization of aniline and pyrrole. The copolymerization of thiophene and aniline is also studied. The electrical conductivity is elucidated in this sections.
The third section involve the silane modification of aniline to increase the thermal stability of the copolymer. The thermal phenomena are elucidated in this research.
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Chen, Yi-Jie, and 陳怡潔. "Structure and properties of water-soluble polyaniline and porous polyaniline membrane." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/04897272703282890330.
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碩士<br>長庚大學<br>化工與材料工程研究所<br>95<br>Polyaniline is an intrinsically conducting polymer because of ease in preparation and good environment stability; therefore it has potential for electronics industry applications. Since it is limited in solubility of most common solvents and only soluble in solvents with high boiling points, it causes a lot of difficulties on the manufacturing process. In this thesis, a water soluble conducting polyaniline was prepared by hydrogen bond interaction with formic acid, succinic acid, benzoic acid, malonic acid and poly acrylic acid. The dialysis time effect on the doping level of polyaniline was analyzed by UV-Vis near IR. It was also found by FT-IR spectra that only a little amount of carboxylic acid was used to make polyaniline soluble in water. After doping with succinic acid for 8 hrs, the conductivities of solid polyaniline film increase from 3.1×10-9 up to 3.6×10-3 S/cm, a six orders increasing, as measured by conductivity and EPR analysis. In XRD spectra, the structures of polyaniline changed from amorphous phase to crystalline phase after doping with carboxylic acid. After doping with either formic acid or succinic acid, no toxic effect of polyailine film on the growth of HEK 293 cells was found. The HEK 293 cells even grew better in PAn-SA film as analyzed by HEK 293 cells biocompatibility tests. Meanwhile, a porpous membrane polyaniline and polyaniline blended membrane was prepared by a simple freeze gel method. After the extraction of ethanol, the smaller pore size and denser structure of the blended membrane was observed as measured by SEM.
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Chung, Wei Ming, and 陳偉明. "Study of polyaniline complex." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/a47atf.
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You, Yun-wen, and 尤韻雯. "Preparation and characterization of Fe3O4 nanowire–polyaniline composites and Ag nanowire-polyaniline composites." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/14663905001244124071.
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碩士<br>國立中央大學<br>化學工程與材料工程研究所<br>97<br>In this thesis, we study two research topics: one is the composite of Fe3O4 nanowire and polyaniline, the other is the composite of silver nanowire and polyaniline. In the first part, the Fe3O4 nanowires (diameter: 50nm, aspect ratio: 150) were previously dispersed in the polyethylene glycols (PEG) solution obtained from Industrial Technology Research Institute. Fe3O4-polyaniline was prepared by polymerization of aniline in the presence of Fe3O4 nanowires, dodecylbenzenesulfonic acid (DBSA) and ammonium persulfate (APS). We varied the relative amount of Fe3O4 nanowires to aniline monomer. The morphology of core-shell structure was observed by SEM and TEM. FTIR spectra show functional groups of polyaniline synthesized. TGA was used to measure the content of Fe3O4 nanowires. Vibrating sample magnetometer (VSM) was used to measure the magnetic properties. Four-Point Probe method was used to measure the conductivity. The prepared composites show both properties of conductivity and magnetism. The thermal stability of the polymer can be enhanced by forming the composites.
In the second part, the Ag nanowires were previously dispersed in polyvinylpyrrolidone solution obtained from Industrial Technology Research Institute. Ag nanowires -polyaniline was prepared by five different methods. Four methods were prepared in aqueous solution, and one of the methods was prepared in chloroform solution. We use thioglycolic acid to modify the surface of Ag nanowire, and then polymerization of aniline occurs near the surface of Ag nanowires. The morphology of core-shell structure was observed by SEM and TEM. FTIR spectra show functional groups of polyaniline synthesized. TGA was used to measure the content of Ag nanowires. Semiconductor parameter analyzer was used to measure the conductivity. The composites prepared by using thioglycolic acid as dopant, and ammonium persulfate (APS) as the oxidant were the best.
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Chen, Kang-Hung, and 陳岡宏. "The study of montmorillonite/epoxy, montmorillonite/polyaniline and polyaniline tubes in nano-materials." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/54035787015932969513.
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"Electrochemistry of Polyaniline-DNA System." East Tennessee State University, 2004. http://etd-submit.etsu.edu/etd/theses/available/etd-0331104-130134/.
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Levin, Zachary Solomon. "Polyaniline-Based Nanocomposite Strain Sensors." Thesis, 2011. http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10322.
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Health monitoring is an important field as small failures can build up and cause a catastrophic failure. Monitoring the health of a structure can be done by measuring the motion of the structure through the use of strain sensors. The limitations of current strain sensing technology; cost, size, form could be improved. This research intends to improve current strain sensing technology by creating a conductive polymer composite that can be used monitor health in structures. Conductive polymer composites are a viable candidate due to the low costs of manufacturing, tailorable mechanical and electrical properties, and uniform microstructure. This work will focus on determining if a all-polymer composite can be used as a strain sensor, and investigating the effects of filler, doping and latex effect the electrical and strain sensing properties.
Strain sensors were prepared from polyaniline (PANI)-latex composites, the morphology, mechanical, electrical and strain sensing properties were evaluated. These strain sensors were capable of repeatable measuring strain to 1% and able to measure strain until the substrates failure at 5% strain, with a sensitivity (measured by gauge factor) of between 6-8 (metal foil strain sensors have a gauge factor of 2). The best performing strain sensor consisted of 4 wt.% polyaniline. This composition had the best combination of gauge factor, linearity, and signal stability.
Further experiments were conducting to see if improvements could be made by changing the polymer used for the matrix material, the molecular weight and the level of doping of the polyaniline. Results indicate through differences in strain sensing response; lower hysteresis and unrecoverable conductivity, that polyaniline latex composites can be adjusted to further improve their performance.
The polyaniline-latex composites were able to repeatable measure strain to 1%, as well as strain until failure and with gauge factor between 6-8, and a 70% increase in signal at failure. These properties make these composites viable candidates to monitor health in structures, buildings, bridges, and damns.
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Chen, Chien-Hsiang, and 陳建翔. "Electrical Property of Polyaniline Nanofibers." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/t22rku.
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碩士<br>國立交通大學<br>電子物理系所<br>96<br>We present temperature dependent current-voltage behaviors of doped-PANI/HCl nanofiber devices with a two-probe configuration. The contribution of electrical transport result not only from the intrinsic PANI/HCl nanofibers but also from the contact. In order to reduce the contact resistance so as to obtain the intrinsic electrical property of the PANI/HCl nanofibers, the contacts of our nanofiber devices were exposed to the electron beam in the scanning electron microscope.
The temperature dependent resistance of our PANI/HCl nanofiber devices reveal a negative temperature dependence (dρ/dT <0) and display semiconducting behaviors. The resistance can be fitted well with the variable range hopping (VRH) model, and the dimensional parameter p lie in the range of 1 - 10. The conduction can be understood as electron hopping between localized states in a disorder system. Moreover, we found that the nanofiber devices with low room-temperature resistances could exhibit intrinsic electrical properties of PANI/HCl nanofibers which the p value smaller than 3 so we argue that PANI/HCl nanofibers could be taken as a quasi-one dimension system. On the other hand, the nanofiber devices with high room-temperature resistances show contact electrical properties with the dimensional parameter p > 3.
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White, Honda, and 白鴻達. "Synthesis of zeolite encapsulated polyaniline." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/99583335277678670054.
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碩士<br>國立中央大學<br>化學工程研究所<br>82<br>The polymerization of polyaniline in appropriate zeolite inrder
to synthesize isolated straight chain polymer with fewefects.
This series of studies try to intercalate polyanilinen
different zeolites with different pore size in three methods:
nilium ion exchange oxidative polymerrization, vacuum
adsorptionxidative polymerization and photopolymerization. In
anilium ionxchange oxidative polymerization, the polymer is
identified asolyaniline from IR,UV-Vis and NMR spectrum. The
delocalizationf polyaniline's electrons is characterized by
EPR. The weightverage molecular weight of the polymer was
characterized byPC and was between 1200-3000. In vacuum
adsorption oxidativeolymerization, we prove the polymers
polymerizing in the poress polyaniline by IR spectrum,the
weight average molecular weights smaller than that of anilium
ion exchange oxidativeolymerization. In photopolymerization, we
can judge if theeaction occurs by observing the change of
colors apparently.
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Chih, Yi-Kai, and 池易楷. "Nanomaterials of Self-Doped Polyaniline." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/61861576625777819608.
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碩士<br>南台科技大學<br>化學工程系<br>93<br>Polyaniline (PANI) is a conducting polymer that has been widely studied for electronic and optical applications. Which the investigation of materials with nanotubular structure is of great importance from both scientific and technological points of view due to their unique propertied and promising potential applications in nanodevices. In recent year, PANI nanostructures, including nanowires, nanotubes, and nanofibers have been studied with the expectation that such materials will possess a variety of advantages.
In this,Self-doping polyaniline (SPANI) nanofibers were synthesized by using self-assembly process consisting of a self-doping monomer (o-aminobenzenesulfonic acid, SAN) and aniline (AN). SAN plays the key roles of a self-doping monomer and a surfactant in the process of forming nanostructures. TEM and SEM results revealed that the morphology, average diameter of the resulting nanostructures depended on the mole ratio of AN to SAN and reaction conditions. NMR, FTIR, XPS, UV-Vis spectra were used to describe the molecular structures of the nanostructures. X-ray diffraction was used to characterize the degree of order in nanometer range structures. Results revealed that the molecular structures of polymer chains were similar to those of the emeraldine form of polyaniline (PANI). The doping degree ranged from 21 to 27 % corresponding to the AN/SAN mole ratio from 4 to 1.
In the second part, The self-doped polyaniline demonstrates nanotube and nanofibril structures corresponding to the AN/SAN mole ratio of 4 and 1, respectively, through the examination of transmission electron microscopy. Reduction of ionic silver along the nanotubes resulted in the production of nanorod about 140 nm in diameter. An immersing self-assembly method was developed to buildup an SPANI nanofibril or nanofilm on an ITO glass, providing an electrode material to fabricate a stable electrochromic device. Total solid-state electrochromic device was fabricated under atmospheric conditions and presented the following configuration:
ITO ∣ SPANI nanofilm ∥ WPU/LiClO4∥ PEDOT-PSS∣ITO
This device showed blue at +1.5 V and pale grey at -1.5 V with respect to a SPANI potential, respectively.
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Kabomo, Tlhabologo Moses. "Properties of nanometal-polyaniline composites." Thesis, 2011. http://hdl.handle.net/10539/10307.
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Polymeric nanocomposites are intimate combinations of a polymer with inorganic
nanoparticles. Such nanomaterials have attracted significant attention over the years
because of their potential uses as chemical sensors, electronic and optical devices, and
as catalysts. For catalytic applications, in particular, small and well dispersed
nanoparticles are desired. We report here the synthesis of gold-polyaniline (AuPANI)
nanocomposites and their catalytic performance. The simple synthetic route involved
pre-organizing the gold ions in polyaniline (PANI) through complexation followed by
the addition of a reducing agent. Control over the degree of reduction of
tetrachloroaurate ions (AuCl4
–) depends on the electrochemical potential of the system
which in turn depends on the molar ratio of the nitrogen atoms on PANI to AuCl4
–.
Gold nanoparticles formed when the AuPANI complexes were reduced with sodium
borohydride and the size of the nanoparticles could be varied with adjustment of the
amount of sodium borohydride used. Low amounts of sodium borohydride induced
slow nucleation rate and were associated with relatively large metallic particles. The
smallest gold nanoparticles with a narrow size distribution were obtained when a ratio
of sodium borohydride:gold of about 6:1 was used. Simple electrolytes like NaCl and
NaOH did not induce the aggregation of Au nanoparticles as predicted by the DLVO
theory. However, chain-like aggregates formed when aggregation was induced by the
reduction of PANI while close-packed aggregates formed when PANI was oxidized
or protonated. The Au nanoparticles were found to be more stable when dispersed on
ring-substibuted PANI than on unsubstituted PANI. The catalytic performance of
AuPANI was evaluated using the reduction of 4-nitrophenol by sodium borohydride.
The reaction was observed to follow the Langmuir-Hinshelwood kinetics.
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Huang, Yi-Ming, and 黃逸閩. "Iron Corrosion Inhibition by Polyaniline." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/30886214844522247250.
Full textAbstract:
碩士<br>淡江大學<br>化學學系碩士班<br>96<br>In this research, p-PANI was prepared in a solution containing 0.15 M aniline and 0.20 M phosphoric acid (pH = 2.19) on a low carbon steel (SAE 1018) substrate by a 2.00 V DC power source in order to study the anti-corrosion effect of the electropolymerized film. Comparing the corrosion potential of p-PANI/steel with the bare steel by the Tafel plot (scanning rate, 1 mV/s; potential range, -0.9 V to -0.1 V), the former is 111 mV higher than the latter. The blue p-PANI had two XRD peaks at 2θ = 20.35° and 25.48°. They are probably due to the long range ordering of the quinoid and benzenoid rings. The rings have a length near 4.39 Å and the parallel packed polymers have a van der Waal distance of 3.51 Å. FT-IR spectra of the p-PANI show absorption bands at 1578 cm-1 and 1490 cm-1 corresponding to the quinoid (C=N) and benzenoid (C=C) rings, respectively. The p-PANI/steel film has a porous morphology observed under SEM. Dissolving the p-PANI in DMF, the 618 nm absorption corresponding to the π-π＊transition is found in the UV-Vis spectra that is a characteristic peak of emeraldine base. Adding a PPDT, poly(2-N-phenylamino-4,6-dimercapto-S-triazine), layer between PANI and steel. PPDT is strongly adsorbed on the surface of steel and allows low permeability of water and oxygen. As a consequence, the corrosion potential of p-PANI/PPDT/steel is further increased, 200 mV higher than the bare steel. Hence, the p-PANI/PPDT bilayer material has a better anti-corrosion effect.
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Tang, Shiow-Jing, and 湯秀靜. "Synthesis and characterization of polyaniline." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/78749842992720593762.
Full textAbstract:
博士<br>中原大學<br>應用物理研究所<br>99<br>Effects from various initial molar ratios of aniline, APS, and HCl ([AN]:[APS]:[HCl]) on the polymerization of aniline were investigated. First, a scheme derived from a molecular point of view was proposed to distinguish the formation mechanisms based on their initial conditions. Then, by choosing a relatively low ratio of [APS]/[AN] = 0.23 at [AN] = 0.27 M, three cases can be categorized according to this scheme: (A) [AN] &gt;&gt; [HCl], (B) [AN] slightly larger than [HCl], and (C) [AN] &lt; [HCl]. For case (A), the initial solution has a richness of neutral anilines. Both the doped and dedoped samples are confirmed to have features of phenazine-like oligomers. For case (C), neutral anilines are almost protonated to become anilinium cations. The final products possess features of polyaniline. For case (B), the samples possess both features from cases (A) and (C). Finally, the formation mechanisms for polymerization of aniline were discussed.
Polyaniline (PANI) films consisted of emeraldine base (EB) powders made by various pressing pressures p and sandwiched by two Au-electrodes are characterized by current-voltage (I-V) measurements. A linear behavior in I-V curves is observed and from which the dark electrical conductivity of the sandwiched Au/PANI/Au sample is deduced. The sample is then put into a cryostat to study the variations in upon dynamic vacuum-pumping and under cooling processes. During dynamic vacuum-pumping process, H2O molecules inside the film are gradually removed from the lateral edge, thus, decreases. The temporal decay in (t) of these dedoped PANI films can be fitted via a stretched exponential function and from which the decay exponent and decay time constant associated with the diffusion of H2O molecules out of the as-pressed film can be obtained. The relations for and with respect to p are discussed, respectively. Next, by measuring the temperature dependence of (T) of these dedoped PANI films, the charge-carriers transport is discussed in terms of 1D variable-range-hopping model and Arrhenius activated-barrier-crossing model, respectively. Finally, the physical significance from the fitting results is discussed.
Electrical characterization of pelletized samples made from polyaniline (PANI), phenazine-like aniline oligomer (PZAO) and PANI/PZAO composite together with the effects from de-doping and re-doping were studied. A numerical fit by using Arrhenius nearest-neighbor hopping, quasi-1D and 3D variable-range hopping models was applied. For samples composed of PANI nanogranules/nanofibers obtained at high [HCl] = 1.0 M, both as-prepared and re-doped samples possess high σDC with a weak T-dependence due to the dopants effects; and small EA (4.8 and 18 meV) for nearest-neighbor hopping and large L and N(EF) for quasi-1D and 3D variable-range hopping were obtained. After de-doping, low σDC with a strong T-dependence was obtained and large EA (520 meV) and small L and N(EF) were resulted. For samples composed of planar PZAO structure obtained at [HCl] = 0.10 M, σDC becomes very small. Both as-prepared and re-doped samples possess high EA (510 and 580 meV), and after de-doping EA increases (870 meV). For samples composed of PANI/PZAO composites obtained at [HCl] = 0.20 M, both as-prepared and re-doped samples possess relatively high σDC at 320 K and low EA (33 and 41 meV); and after de-doping, EA increases again (420 meV).