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Síntese e aplicação de polímeros condutores em sensores olfativos; Synthesis and application of conductive polymers in olfactory sensors

Cordeiro, Juliana Ribeiro
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 25/02/2010 PT
Relevância na Pesquisa
58.30287%
Os objetivos do trabalho consistem em síntese e caracterização de três polímeros: poli(2,1,3-benzotiadiazol-4,7-ilenovinileno) (PBTDV), poli(2,1,3-benzotiadiazol-4,7-ilenovinileno-co-2-bromo-5-hexilóxi-p-fenilenovinileno (PBTDV-co-BHPPV) e poli(2-bromo-5-hexilóxi-p-fenilenovinileno) (BHPPV), sendo os dois primeiros inéditos; aplicação de polímeros condutores no desenvolvimento de um nariz eletrônico capaz de identificar madeiras; e aplicação de polímeros condutores em um sensor de pressão. Os polímeros foram preparados de maneira satisfatória via redução catódica de seus precursores tetra-halogenados, que forneceu produtos com rendimentos apreciáveis. Para o projeto do nariz eletrônico que pretende identificar madeiras, dois conjuntos de espécies de madeira foram estudadas: (a) mogno e cedro e (b) imbuia e canela-preta. O nariz eletrônico desenvolvido apresenta um conjunto de quatro sensores de gás, que foram construídos por meio da deposição de finos filmes de polímeros dopados sobre a superfície de eletrodos interdigitados. Esse conjunto de sensores foi desenvolvido com sucesso, sendo capaz de diferenciar as espécies de madeira com taxa de acerto de 100%. Por fim, foi desenvolvido também com sucesso um sensor de gás capaz de atuar como sensor de pressão. Esse dispositivo mostrou-se sensível à variação de pressão...

Identificação de plásticos comerciais por meio de um nariz eletrônico baseado em polímeros condutores.; Identification of plastics commercials through an electronic nose based on conducting polymers.

Martins, Gilmar Antonio dos Santos
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 07/04/2011 PT
Relevância na Pesquisa
47.55296%
O presente trabalho consiste no desenvolvimento de uma nova técnica de identificação de materiais poliméricos por meio do uso de um nariz eletrônico. Narizes eletrônicos têm sido desenvolvidos para detecção automática e classificação de odores e gases. São instrumentos capazes de medir a concentração ou intensidade odorante de modo similar a um olfatômetro, mas sem as limitações inerentes ao uso de painel humano, o que é altamente desejável. O nariz eletrônico é composto por um sistema de sensores, no nosso caso, utilizamos um arranjo de quatro sensores, que foram confeccionados pela deposição de finos filmes de polímeros condutores dopados sobre a superfície de eletrodos interdigitados. Estes sensores foram conectados a condutivímetros acoplados a um computador de uso pessoal (PC) através de um conversor AD. O PC era dotado de softwares de aquisição e tratamento de dados. Amostras dos materiais a serem analisados foram aquecidas a 257°C e o arranjo de sensores foi exposto aos compostos voláteis produzidos durante esse aquecimento. Realizaram-se 30 ensaios formados por períodos de exposição (5 segundos; compostos voláteis) intercalados por períodos de recuperação (45 segundos; ar puro). Os dados obtidos foram tratados estatisticamente por Análises de Componentes Principais (PCA). Esse arranjo de sensores mostrou-se eficiente...

Estudo de polímeros condutores iônicos e eletrônicos dopados com metais alcalinos utilizando-se espectroscopia de alta resolução em sólidos por ressonância magnética multinuclear; Ionic and electronic alkaline metal doped conductive polymer studies using high resolution multinuclear solid-state nuclear magnetic resonance

Giotto, Marcus Vinicius
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 28/04/1997 PT
Relevância na Pesquisa
48.284375%
As técnicas de Espectroscopia de Alta Resolução em Sólidos e Relaxação por RMN são largamente utilizadas no estudo da estrutura e dinâmica de polímeros. Neste trabalho estudamos, utilizando estas técnicas, duas classes distintas de polímeros: os condutores iônicos e os condutores eletrônicos. O polímero condutor iônico estudado foi o Diesterato de Polietileno Glicol (PEGD) complexado com sais de metais alcalinos, LiClO4 ou NaClO4. A metodologia básica que empregamos para o estudo destes materiais foi a análise da forma de linha e do tempo de relaxação longitudinal para os núcleos associados tanto aos portadores de carga, 7Li e 23Na, quanto à cadeia polimérica, 1H e 13C. Todas estas medidas foram realizadas em função da temperatura e da concentração de sal de metal alcalino presente na amostra. Estudos adicionais, por condutividade elétrica, análise térmica e viscosidade foram realizados para complementar o conhecimento obtido por RMN sobre a mobilidade e estrutura das cadeias poliméricas e dos portadores de carga. Os polímeros com ligações de elétrons-'pi' conjugados apresentam propriedades eletrônicas especiais, particularmente a condutividade elétrica, e formam uma classe de polímeros condutores eletrônicos que podem ser facilmente oxidados ou reduzidos através de um agente dopante. Estudamos dois polímeros deste tipo: As polianilinas dopadas com 1H ou 7Li. A metodologia básica que empregamos para o estudo destes polímeros foi a análise das formas de linhas espectrais de um dos núcleos que compõem a cadeia polimérica...

Thermal analysis of conductive blends of PVDF and poly(o-methoxyaniline)

Malmonge, L. F.; Mattoso, L. H C
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 8387-8391
ENG
Relevância na Pesquisa
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The thermal behavior of blends of poly(vinylidene fluoride), or PVDF, and poly(o-methoxyaniline) doped with toluene sulfonic acid was studied by thermogravimetic analysis, electrical conductivity measurements, differential scanning calorimetry, X-ray diffraction and scanning electron microscopy. Blends with thermal and electrical conductivity stabler than the conductive polymer alone were obtained. Nevertheless, degradation occurs after a long period of time (500 h) at high temperatures. The possible association of the conductivity decay with dopant loss, degradation and structural and morphological changes of the blend is discussed. (C) 2000 Elsevier Science Ltd.; The thermal behavior of blends of poly(vinylidene fluoride), or PVDF, and poly(o-methoxyaniline) doped with toluene sulfonic acid was studied by thermogravimetic analysis, electrical conductivity measurements, differential scanning calorimetry, X-ray diffraction and scanning electron microscopy. Blends with thermal and electrical conductivity stabler than the conductive polymer alone were obtained. Nevertheless, degradation occurs after a long period of time (500 h) at high temperatures. The possible association of the conductivity decay with dopant loss, degradation and structural and morphological changes of the blend is discussed.

Correlações entre estrutura e propriedades de condução iônica em materiais híbridos siloxano-poli (propileno óxido), dopados com sais de sódio e potássio

Chaker, Juliano Alexandre
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Tese de Doutorado Formato: 160 f. : il.
POR
Relevância na Pesquisa
47.79352%
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Pós-graduação em Química - IQ; Materiais híbridos orgânicos-inorgânicos são materiais bifásicos onde a interpenetração das fases em uma escala nanométrica permite preparar materiais com propriedades inéditas. Este é o caso dos eletrólitos sólidos transparentes siloxano-poli(propileno óxido) estudados neste trabalho de doutorado. Este trabalho visou estabelecer correlações entre as propriedades de condução iônica e as características estruturais destes híbridos que são preparados pelo processo sol-gel. Os objetivos específicos propostos no projeto original incluem os seguintes itens: (a) estabelecer correlações entre a estrutura e as propriedades determinantes da condutividade iônica; (b) analisar a estrutura local do dopante, sua localização no sistema, e assim determinar os sítios de adsorção bem como sua participação na formação da ligação O-Na-O ou O-K-O envolvendo oxigênios tipo éter da cadeia polimérica; (c) determinar o efeito da retração e da formação de domínios com correlação espacial em função dos diferentes sais dopantes estudados sobre as propriedades de condução iônica; (d) comparar as propriedades e estrutura dos híbridos preparados com polímeros de diferentes massas moleculares e concentrações de dopante. Para isto...

Effect of the processing conditions on the mechanical and electrical properties of extruded conductive PP tape and filament

Silva, Marco Aurélio Pinto; Martins, R. S.; Nóbrega, J. M.; Carvalho, Helder; Lanceros-Méndez, S.
Fonte: Sociedade Portuguesa de Materiais Publicador: Sociedade Portuguesa de Materiais
Tipo: Conferência ou Objeto de Conferência
Publicado em /04/2011 ENG
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Polypropylene (PP) shows a number of desirable properties that make it a versatile material among thermoplastic polymers. Due to its low cost and density, it is an excellent resin for conductive polymer composites (CPCs).[1] CPCs mainly consist on a polymer matrix with incorporated carbonaceous fillers. These multifunctional materials are routinely employed in various commercial applications due to their good electrical conductivity, corrosion resistance, light weight and enhanced mechanical properties. [2] The filler content is the crucial aspect in conductive polymer composites fabrication: due to mechanical behaviour it must be as low as possible but enough to allow fulfilling the electrical requirements.[2] In this work commercial conductive master batch PP was extruded in the form of tape and filament using different processing conditions, namely different draw ratios and temperatures. In order to tailor the mechanical performance of the material, different several amounts of PP homopolymer were added to the commercial conductive resin. The results show that the amount of homopolymer directly influences mechanical and electrical performance of the material. Increasing homopolymer content yields a more stretchable, and mechanically resistant...

Properties and processing by extrusion of electrically conductive multilayer filaments comprising polymer composites

Martins, R. S.; Gonçalves, Renato Ferreira; Azevedo, Tiago; Nóbrega, J. M.; Carvalho, Helder; Lanceros-Méndez, S.; Rocha, J. G.
Fonte: Sociedade Portuguesa de Materiais (SPM) Publicador: Sociedade Portuguesa de Materiais (SPM)
Tipo: Conferência ou Objeto de Conferência
Publicado em //2013 ENG
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This work describes the production and characterization of three-layer piezoelectric filaments using two different electrically conductive polymers. The filaments were produced in a filament extrusion line, equipped with a coextrusion die that enabled a coaxial arrangement for a three-layer filament. For the inner and outer layers two different electrically conductive compounds were used, and the middle layer was made of the electroactive polymer PVDF. The produced filament can be used as a piezoelectric sensor, as described in other work [1]. A commercial conductive polymer grade of polypropylene compounded with carbon black and a commercial polypropylene containing 7 wt% of carbon nanotubes were studied and compared when employed as the filament conductive layers under various processing conditions, namely different process temperatures and drawing ratio. For evaluation purposes measurements of the electrical resistance of the inner and outer conductive layers were performed and correlated with the composition and processing conditions. The polypropylene based composite containing 7 wt% carbon nanotubes revealed to be the most effective material to be used in the production of three-layer piezoelectric filaments since it presents higher electrical conductivity and easier processing...

Synthesis and characterization of electrically conductive bacterial cellulose-polypyrrole composites using alternative synthesis methods

Sousa, Rui César Cardoso de
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Dissertação de Mestrado
Publicado em //2013 ENG
Relevância na Pesquisa
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Dissertação de mestrado em Bioengenharia; As the era of the nanomaterials draws near, the electrically conductive polymeric materials have been receiving increasing attention towards the development of diverse applications in electronics, sensors and actuators. Among these materials, the intrinsic conductive polymers (ICPs) stand out, namely polypyrrole (PPy), an inexpensive and highly conductive ICP (up to 500 S.m-1) of facile synthesis, environmentally stability and biocompatibility. By its turn, bacterial cellulose (BC), a biopolymer with highly versatile characteristics, namely chemical purity (0% pectins and hemicelluloses), high crystallinity (95%), low density (1.25 g cm-3), high surface area (37 m2g-1) as well as excellent mechanical properties (Young’s modulus of approx. 15-35 GPa) and low-cost production, have also been drawing a lot of attention. With a combination of these material’s promising characteristics in sight, the aim of this work was to obtain electrically conductive BC-PPy composites via in situ polymerization. This was achieved by using wet chemical polymerization method. Never-dried and freeze-dried BC thin films were used as the templates for monomer deposition and polymerization. Additionally...

Piezoelectric co-axial filaments produced by co-extrusion of poly(vinylidene fluoride) and electrically conductive inner and outer layers

Martins, R. S.; Gonçalves, Renato Ferreira; Rocha, J. G.; Nóbrega, J. M.; Carvalho, Helder; Lanceros-Méndez, S.
Fonte: Wiley Publicador: Wiley
Tipo: Artigo de Revista Científica
Publicado em 28/05/2014 ENG
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Article first published online: 3 APR 2014 : http://onlinelibrary.wiley.com/doi/10.1002/app.40710/abstract. DOI 10.1002/app.40710.; The development of new thermoplastic polymer-based piezoelectric sensors with filament geometry is described. These filaments are appropriate for integration into textiles and provide new possibilities in the design and development of low cost flexible sensors produced at high rates. The developed three-layered piezoelectric monofilaments have been produced by co-extrusion using poly(vinylidene fluoride) and two different polypropylene-based electrically conductive polymers. Filaments with about 800 µm diameter, producing electrical signals proportional to the mechanical deformation applied, were obtained. The signal output has been found adequate for straightforward use with conventional piezoelectric signal conditioning systems. One of the conductive polymers tested allowed better filament geometry and process stability. This paper describes the co-extrusion production process and the results obtained in the electromechanical tests performed.; This work was supported by FEDER through the COMPETE Program and by the Portuguese Foundation for Science and Technology (FCT) by project PTDC/CTM/108801/2008 | FCOMP-01-0124-FEDER-009480 and in the framework of the Strategic Project PEst-C/FIS/UI607/20112011...

Síntese de polímeros condutores em matrizes sólidas hospedeiras

Maia,Daltamir J.; De Paoli,Marco-A.; Alves,Oswaldo L.; Zarbin,Aldo J. G.; Neves,Silmara das
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2000 PT
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This review discusses the methods used to prepare conductive polymers in confined environments. This spatial restriction causes formation of defect-free polymer chains in the interlayer as porous cavities of inorganic hosts. The properties of the different composites obtained are a synergist combination of the characteristics of the inorganic host and the polymer. This opens new perspectives for the preparation of these materials and widens its potential applications.

Synthesis and characterization of organic-inorganic hybrids formed between conducting polymers and crystalline antimonic acid

Beleze,Fábio A.; Zarbin,Aldo J. G.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2001 EN
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In this paper we report the synthesis and characterization of novel organic-inorganic hybrid materials between the crystalline antimonic acid (CAA) and two conductive polymers: polypyrrole and polyaniline. The hybrids were obtained by in situ oxidative polymerization of monomers by the Sb(V) present in the pyrochlore-like CAA structure. The materials were characterized by infrared and Raman spectroscopy, X-ray diffraction, cyclic voltammetry, CHN elemental analysis and electronic paramagnetic resonance spectroscopy. The results showed that both polymers were formed in their oxidized form, with the CAA structure acting as a counter anion.

Synthesis, properties and aplications of functionalized polyanilines

Acevedo,Diego F.; Salavagione,Horacio J.; Miras,María C.; Barbero,César A.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2005 EN
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Novel functionalized conductive polymers are synthesised using modification reactions of polyaniline: diazonium coupling, nucleophilic addition and N-nitrosation. Diazonium salt coupling with polyaniline renders modified polymers which are soluble in common solvents and electroactive. Nucleophilic addition could also be used to modify polyaniline. Modified polymers produced by addition of thiols, carbanions and arylsulphinic acids are described. The nucleophilic addition of arylsulphinic acids to oxidized polyaniline is shown to be controlled by the oxidation and/or protonation state of the polymer. It is also possible to N-nitrosate polyaniline producing a material soluble in common solvents. The reaction could be reversed by acid treatment. The reversible nitrosation reaction is used to design lithographic and photolithographic processes to deposit PANI patterns.

Study of poly(o-Ethoxyaniline) interactions with herbicides and evaluation of conductive polymer potential used in electrochemical sensors

Consolin Filho,Nelson; Leite,Fábio de Lima; Carvalho,Eduarda Regina; Venâncio,Everaldo Carlos; Vaz,Carlos Manoel P.; Mattoso,Luiz Henrique C.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2007 EN
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47.67129%
Interactions of four aromatic nitrogen-heterocyclic herbicides (atrazine, imazaquin, metribuzin and paraquat) with the conductive polymer poly(o-ethoxyaniline)-POEA, were studied with atomic force microscopy (AFM), UV-visible spectrophotometry (UV-Vis) and electrochemical impedance spectroscopy. AFM profiles of self-assembled (SA) films of POEA revealed that the polymer surface became rougher (on the nanoscale) when exposed to atrazine, imazaquin and metribuzin, but slightly smoother in contact with paraquat. This suggested that specific chemical interactions, possibly electroscopic, have occurred between nitrogen atoms in the polymer chain and the dissimilar groups in the various herbicide molecules, during adsorption of the latter onto the film. The UV-Vis analyses indicated a stronger interaction of POEA in solution with imazaquin, that has a special importance for the intended application. Sensors produced by coating microelectrodes with SA films of POEA were used to perform impedance spectroscopy in aqueous solutions of each herbicide. With the resulting data, it was possible to distinguish and set detection limits for each herbicide in water, corroborating AFM and UV-Vis results.

Conductive polymers derived from iron, ruthenium, and osmium metalloporphyrins: The shish-kebab approach

Collman, James P.; McDevitt, John T.; Yee, Gordon T.; Leidner, Charles R.; McCullough, Laughlin G.; Little, William A.; Torrance, Jerry B.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /07/1986 EN
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The synthesis and characterization of pyrazine-bridged polymers of iron(II/III), ruthenium(II/III), and osmium(II/III) octaethylporphyrin (dubbed “shish-kebab” polymers) are presented. Optical and dc conductivity measurements reveal that the ruthenium and osmium polymers, when partially oxidized, are highly conductive. Electrochemical and ESR results are presented that indicate the existence of an interesting metal-centered conduction pathway. Unlike most of the previously reported porphyrinic molecular metals in which the conduction electrons are macrocyclic-based, electron transport in these materials proceeds exclusively along the metal-pyrazine backbone.

Efficiency of a compact elliptical planar ultra-wideband antenna based on conductive polymers

Kaufmann, T.; Verma, A.; Truong, V.T.; Weng, B.; Shepherd, R.; Fumeaux, C.
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
Publicado em //2012 EN
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48.67074%
A planar antenna for ultra-wideband (UWB) applications covering the 3.1–10.6 GHz range has been designed as a test bed for efficiency measurements of antennas manufactured using polymer conductors. Two types of conductive polymers, PEDOT and PPy (polypyrrole), with very different thicknesses and conductivities have been selected as conductors for the radiating elements. A comparison between measured radiation patterns of the conductive polymers and a copper reference antenna allows to estimate the conductor losses of the two types of conductive polymers. For a 158 μm thick PPy polymer, an efficiency of almost 80% can be observed over the whole UWB spectrum. For a 7 μm thick PEDOT layer, an average efficiency of 26.6% demonstrates, considering the room for improvement, the potential of this type of versatile materials as flexible printable alternative to conductive metallic paints. The paper demonstrates that, even though the PEDOT conductivity is an order of magnitude larger than that of PPy, the thicker PPy layer leads to much higher efficiency over the whole UWB frequency range. This result highlights that high efficiency can be achieved not only through high conductivity, but also through a sufficiently thick layer of conductive polymers.; Thomas Kaufmann...

Comparison of two planar elliptical ultra-wideband PPy conductive polymer antennas

Kaufmann, T.; Verma, A.; Al-Sarawi, S.; Truong, V.T.; Fumeaux, C.
Fonte: IEEE; USA Publicador: IEEE; USA
Tipo: Conference paper
Publicado em //2012 EN
Relevância na Pesquisa
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Conductive polymers are a new type of conductive materials that are attractive for application in flexible, and possibly reconfigurable antennas. Two planar elliptical ultra-wideband antennas based on conductive polymers are manufactured. The selected Polypyrrole (PPy) polymer exhibits moderate conductivity but can be produced as rather thick free-standing films up to a size of several hundred micrometers. The efficiency of the conductive materials is estimated based on the comparison of the radiation patterns with those of a reference antenna built from copper. The two PPy samples exhibit the same conductivity, but different thicknesses. Higher efficiency is achieved using the thicker PPy sample, demonstrating efficient operation below one skin depth.; http://s15.a2zinc.net/clients/IEEE/APSURSI2012/Public/MainHall.aspx?ID=70; Thomas Kaufmann, Akhilesh Verma, Said F. Al-Sarawi, Van-Tan Truong and Christophe Fumeaux

Modeling conductive polymer antennas in the microwave region

Kaufmann, T.; Shepherd, R.; Fumeaux, C.
Fonte: IEEE; CD Publicador: IEEE; CD
Tipo: Conference paper
Publicado em //2012 EN
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The application of conductive polymers, e.g. PEDOT or PPy, for microwave applications has been researched recently due the advantages of these materials in mechanical flexibility, processability and low cost. A crucial aspect of antenna design is to obtain reliable simulation results. This is particularly challenging for materials with moderate conductivity such as conductive polymers, since the conductivity is in the order of thousands to hundreds of thousands S/m - too low to be a “good conductor”. In this study, a comparison of different modeling techniques generally available in commercial field solvers is conducted. The polymers are either modeled as fully discretized lossy dielectrics, as thin conductive sheets or as impedance boundaries. On the example of an ultra-wideband (UWB) antenna built from samples of PEDOT and PPy, the three modeling techniques are compared in terms of accuracy and computational expenditure in commercial finite-difference time-domain and finite-element codes. The influence of the (often unknown) permittivity of the conductor on the simulation results is investigated. It is shown that for thick conductors, i.e. with thicknesses in the range of the skin depth or above, all three models yield very similar results. For much thinner conductive polymers...

Synthèse des matériaux électroactifs à base de thiophènes et de bipyrroles dissymétriques

Tshibaka, Tshitundu
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
FR
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Le couplage des aldéhydes aryliques et des amines pour donner les azométhines est une alternative intéressante pour la synthèse des comonomères conjugués. Contrairement aux techniques de couplage classiques qui conduisent à des mélanges de produits, il est possible, par cette méthode, d’obtenir sélectivement des composés ciblés et dissymétriques tout en contrôlant la stœchiométrie des réactifs et les solvants. Dans le cadre de nos recherches sur les matériaux fonctionnels ayant des propriétés électrochromiques améliorées, nous avons planifié de conjuguer des thiophènes et des bipyrroles dissymétriques par les liaisons azométhines. Tout d’abord des analogues des 4-méthoxy-2,2’-bipyrroles 1-2 (chapitre 2) et 3-6 (chapitre 3) ont été synthétisés par une voie générale à partir de 4-hydroxyproline et convertis ensuite en dialdéhydes 8-13 (chapitre 3) qui, à leur tour, ont subit des condensations avec différents aminothiophènes pour donner les azométhines conjugués 17-23 (chapitre 3).; The condensation of amine and aldehyde functional groups is an attractive strategy for the synthesis of conjugated, conductive polymers. Unlike conventional coupling techniques that give a mixture of products...

Printing studies with conductive inks and exploration of new conducting polymer compositions

Karwa, Anupama
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado Formato: 12215 bytes; 2724151 bytes; application/pdf; application/pdf
EN_US
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In addition to low cost and high volume, continuous production of devices such as transistors and RFID tags, printable electronics show promise in the fabrication of a multiplicity of sensors, displays, photovoltaic arrays, smart cards, etc. Due to flexibility and insensitivity to substrates, the use of organics in printed electronics has opened up a number of new opportunities in novel applications. In the present work, the process capability of flexography and offset lithography for patterning conductive materials was determined using small scale equipment (rotary letterpress and duplicator respectively). Process parameters including: type of substrate, line widths, line gaps, print thickness, directional effects, etc. were investigated. It was thus shown that the high volume printing processes of offset lithography and flexography can be used to obtain functional printed conductive patterns. In order to have greater control over ink composition and physical characteristics than was afforded by commercially available silver metal filled conductive inks, polyaniline (PANI) was synthesized by interfacial polymerization. Printable flexographic inks were formulated therefrom and a PANI ink was used in the flexographic printing of a working gas sensor. The conductivity of these inks was lower than that of silver filled metallic inks. This mitigated their utility in their utility in the printing of functional RFID antennae. Poly (thiophene-2...

Electrical characterization and electrogenic cell stimulation using a conductive polymer composite based on PEDOT:PSS/PVA/EG

Suárez-Vargas,José; Calderón,Marbely; Brämer-Escamilla,Werner; Briceño,Sarah; Sánchez,Iván; Bolaño,Pura; Caputo,Carlo
Fonte: Universidad Simón Bolívar; ; Publicador: Universidad Simón Bolívar; ;
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2015 EN
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Modern microelectrode arrays are being developed with emergent materials and approaches that provide properties superior to conventional metallic and inorganic semiconductor based electrodes. Newer materials include conducting polymers, nanotubes and graphene-based films. Here we propose a composite mixture with controlled electrical properties based on the p-type conductive polymer poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonate) (PEDOT:PSS). To improve the biocompatibility and conductivity of the material, we added a combination of the polar organic compound ethylene glycol (EG), the surfactant sodium dodecyl sulfate (SDS) and polyvinyl alcohol (PVA). Using these mixtures, we fabricated films to interface electrical stimuli with rodent skeletal muscle fibers and ventricular cardiomyocytes. We demonstrated strong contractile responses and excellent biocompatible cell coupling with polymer-based films.