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Dulgerbaki, Cigdem. "Synthesis And Characterization Of Polythiophene/montmorillonite And Polythiophene/polypropylene Composites". Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/2/12607762/index.pdf.
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In this study, polythiophene(PTP)/montmorillonite(MMT) nanocomposites were synthesized by in situ intercalative polymerization and chemical oxidative polymerization. In in situ intercalative polymerization method, composites containing 90 and 95% MMT were prepared. In chemical oxidative polymerization method, a series of composites ranging from 1 to 15% by weight MMT were synthesized. Thermal and morphological properties of samples were investigated by Differential Scanning Calorimeter (DSC), Thermal Gravimetric Analysis (TGA), X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM)electrical conductivities were measured by four probe technique. Since PTP/MMT composites are unprocessable PTP/polypropylene(PP) composites were prepared. Amounts of PTP were changed in the range 2-30 % by weight in the composites. Mechanical properties were investigated by tensile tests. Four probe technique was used for measurement of electrical conductivities. Morphological characterizations were made by SEM. Formation of PTP and its incorporation in PTP/MMT composite were confirmed by FTIR analysis. DSC results showed that PTP does not have any thermal transition in the range 25-300 0C. TGA results showed that PTP/MMT composites have outstanding stability compared to that of PTP. XRD analysis revealed the formation of nanocomposites resulting from intercalation of thiophene in MMT at high MMT contents. Composites were observed as globular particles and clusters in SEM studies. Conductivity values of PTP/MMT composites were in the order of 10-3 S/cm. It is observed that tensile modulus of PTP/PP composites increases by the addition of PTP, but percentage strain at break does not appreciably change. Increasing PTP content increased electrical conductivity.
2
Stromberg, Christian. "Transportprozesse bei der Bildung und Modifizierung technisch relevanter Polythiophene". [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=971958092.
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Santoso, Handoko Tirto. "Electrochemical processing of polythiophene films with enhanced structural order". Thesis, Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/42696.
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Intrinsically conducting polymers (ICPs) with high mechanical strength and electrical conductivity are attractive for several applications spanning the fields of energy, defense, and transportation. Electrochemically processed polythiophene (PTh) films are a class of ICPs that have been demonstrated recently to possess electrical conductivities as high as 1,300 S/cm and be stronger than common types of processed aluminum foils. While these results are promising, the electrical conductivity of PTh is still low compared to metals and the effects of important process conditions such as electrode resistance, distance between working and counter electrodes, and thiophene concentration on the structure and physical properties of electrochemically processed PTh films must be investigated in detail. In this work, electrode resistance and inter-electrode distance were demonstrated to be inversely proportional to the charge efficiency for PTh film growth. A critical concentration of thiophene that produced films with the highest conductivity was also revealed. Anionic surfactants sodium dodecyl sulfate (SDS) and sodium dodeclybenzene sulfonate (SDBS) were used, with and without a proton scavenger, in the Lewis acid boron trifluoride diethyl etherate (BFEE) electrolyte, which allows polymerization of thiophene at low oxidation potentials, to enhance the ordering and conjugation length of PTh through stabilization of the radical cation of thiophene via the dodecyl chain of the anionic surfactants. X-ray diffraction spectra revealed enhanced order and packing when surfactant was used during the processing of PTh films, and measured electrical conductivities were increased by as much as 300% because of the surfactant-mediated structural improvements. Necking behavior observed in tensile test of PTh films with anionic surfactant additives also suggests chain alignment and increased chain length.
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Schneider, Mareike. "Polythiophene als sensitive Filme in chemischen Sensoren". Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2002. http://nbn-resolving.de/urn:nbn:de:swb:14-1042708889359-42815.
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This work deals with the sensor application of polythiophenes, which belong to the group of the conducting polymers. The first part focuses on sensor application of poly(3,4-ethylenedioxythiophene) (PEDOT) for ion detection in aqueous electrolytes. The advanced electrochemical quartz crystal microbalance was used for investigating the electrochemical polymerisation and the redox cycling behaviour of the polymer films deposited on the liquid facing electrode of the quartz. This method is based on impedance analysis of a piezoelectric quartz crystal. The deposited polymer mass and surface roughness parameters were estimated from the electrical impedance shift of the quartz during the polymerisation using a new calculation procedure for rough and viscoelastic films. The PEDOT data were compared with results from the electrochemical polymerisation of 2,2?-bithiophene to demonstrate the influence of the substituent on morphology and electrochemical properties in organic electrolytes. With regard to electrogravimetric sensor applications the ion exchange of the polymer in aqueous electrolytes (LiClO4, NaClO4, NaNO3, and sodium toluenesulfonate) during redox cycling was investigated. From the mass/charge balance the apparent exchanged molar mass and the absolute exchanged mass of ions were calculated. The mass balance indicated a transfer of anions and solvent during oxidation. No remarkable cation exchange in the reduction scan was observed. For all investigated electrolytes the calculated exchanged molar mass can be explained with a reversible replacement of solvent by anions during oxidation. The molar solvent/anion ratio was roughly proportional to the sizes of the species. The second part of the work describes investigations on gas sensing properties of polythiophene films prepared by a new preparation method. This two-step procedure is based on electroless polymerisation of conducting polymers. In the first step the substrate is coated with an adhesion promoter and in a second step the chemical surface polymerisation of the monomer is performed. This deposition method was combined with new patterning techniques. The basis of this process is the patterned application of the adhesion promoter which was realised either by a photoresist lacquer mask or by micro contact printing of the adhesion promoter solution. These methods provide patterning down to submicrometer scale. The sensing properties of the polythiophene films were demonstrated with chemiresistors for the redox active gases NO2 and NH3. The reaction kinetics were investigated depending on humidity and temperatureDie Arbeit befasst sich mit der Untersuchung von Polythiophenen, einer Gruppe der intrinsisch leitfähigen Polymere, für die Anwendung als sensitive Filme in chemischen Sensoren. Ziel war es dabei, ausgewählte Aspekte des Sensoreinsatzes dieser Polymere zu beleuchten, um Wege zu einer verbesserten Sensorcharakteristik solcher Systeme aufzuzeigen. Der erste Teil der Ergebnisse konzentriert sich auf den Einsatz von Poly(3,4-ethylendioxythiophen) in Sensoren für die Bestimmung von Ionenkonzentrationen in wässrigen Medien. Die elektrochemische Polymerisation auf Schwingquarzen und der potentialinduzierte Ionenaustausch an solchen Polymerfilmen wurden mit Hilfe der elektrochemischen Quarzmikrowaage charakterisiert. Diese beruht auf der Impedanzanalyse von Schwingquarzen in der Nähe ihrer Resonanzfrequenz, was neben der Erfassung der Änderung der Resonanzfrequenz der Quarze auch die Untersuchung des Dämpfungsverhaltens und somit eine halbquantitative Analyse der mechanischen Eigenschaften des Polymerfilmes ermöglicht. Aus den Daten Impedanzanalyse während der Polymerisation wurden mit einem neuen Berechnungsmodells, das viskoelastische und rauhigkeitsinduzierte Einflüsse berücksichtigt, die Polymermasse und vertikale und laterale Rauhigkeitsparameter bestimmt. Der Einfluss des Substituenten auf die Morphologie und das elektrochemische Verhalten in organischen Elektrolyten ist durch Vergleichsuntersuchungen an Poly(2,2?-bithiophen) illustriert. Die Sensormessungen erfolgten in wässrigen Modellelektrolyten mit unterschiedlich großen Anionen (LiClO4, NaClO4, NaNO3, Natriumtoluolsulfonat). Für die potentialabhängige Ionenaustauschreaktion konnte ein Einbau von Anionen bei der Oxidation des Polymers, der mit einem Ausstoß von Lösungsmittel verbunden war, nachgewiesen werden. Bei Reduktion des Polymers war der umgekehrte Vorgang zu beobachten. Kationen waren nicht nachweislich an den Austauschprozessen beteiligt. Als Sensorsignal wurde aus der bei Einbau der Ionen geflossenen Ladung und der reaktionsbedingten Masseänderung die ausgetauschte molare Masse und die inkorporierte Ionenmenge bestimmt. Die ausgetauschte molare Masse ergab für die unterschiedlichen Ionenspezies typische Werte, was eine Identifizierung der jeweiligen Analyten erlaubt. Die berechnete Analytmenge belegte eine erhöhte Empfindlichkeit für das in der Polymerisation verwendete Anion (Perchlorat) und eine geringe Empfindlichkeit für große Anionen (Toluolsulfonat) Für dünne, weniger poröse Filme war das Austauschverhältnis von Anion und Lösungsmittel annähernd proportional zu den Molekülgrößen der beteiligten Spezies. Ein zweiter Schwerpunkt der Arbeit war die Weiterentwicklung eines Verfahrens zur oxidativ?chemischen Abscheidung von Polythiophenfilmen unter Nutzung haftvermittelnder Substanzen. Dafür wurde die Filmqualität experimentell optimiert und Methoden zur strukturierten Abscheidung entwickelt. Zur Strukturierung der Polymerfilme wurden Methoden zur lokalen Aufbringung des Haftvermittlers auf Basis einer Maskierung des Substrates mit photostrukturierbaren Lackmasken bzw. auf Basis des Mikrokontaktdruckes der Haftvermittlerlösung entwickelt. Mit der Maskentechnik konnten Strukturen im Submikrometerbereich, mit dem Mikrokontaktdruck im Mikrometerbereich, erzielt werden. Der Nachweis der Sensitivität der chemisch polymerisierten Polythiophenfilme wurde für redoxaktive Gase mit Hilfe von Leitfähigkeitssensoren erbracht, und die Reaktionskinetik in Abhängigkeit von Feuchte und Temperatur untersucht
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Seidler, N. "Polythiophene nanofibres for optoelectronic applications". Thesis, University College London (University of London), 2014. http://discovery.ucl.ac.uk/1456569/.
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This thesis reports on the fabrication and characterisation of self-assembled nanofibres of poly(3-hexylthiophene) (P3HT), and demonstrates how these nanofibres can be used in applications like thin-film transistors and solar cells. The first results chapter describes a preparation method of P3HT nanofibres in a solution of chlorobenzene by using di-tert butyl peroxide (DTBP) as an additive. This method allows the fabrication of films of P3HT with high molecular order and gives control over the film retention. The films are characterised using a range of experimental techniques, including optical absorption, X-ray diffraction and atomic force microscopy, which also allows to determine the dimensions of individual, separated nanofibres. A more detailed investigation into the temperature dependence of the photoluminescence (PL) of nanofibre films in comparison to P3HT thin-films is presented in the second results chapter. The line-shape of the measured PL of the nanofibres shows significant differences to the thin-film, which is most distinctive at a temperature of around 150K. At this temperature, the measurements show a change of the emission characteristics for the nanofibres which is absent in the thin-film. The cause for the observed transition can be related to the increased planarisation of the polymer backbone inside the nanofibres with increasing temperature. This gives rise to more dominant intrachain coupling for the fibres, in contrast to predominantly interchain coupling in P3HT thin-films. The third results chapter demonstrates the application of the nanofibre films in thin-film transistors and solar cells. It is shown how the high molecular order of the nanofibres in combination with the formation of fibre networks can be used to control the field-effect mobility of P3HT films. Solar cells are fabricated by successive deposition of a nanofibre film and an electron acceptor layer, resulting in power conversion efficiencies comparable to bulk heterojunction solar cells.
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Graves, Colin G. "Electrically conductive adhesives based on polythiophene". Thesis, Anglia Ruskin University, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.410803.
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Simmons, Martin Richard. "Processable forms of polypyrrole and polythiophene". Thesis, University of Sussex, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336326.
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Winkels, Stephan. "Polymerisation und Abscheidung von Kompositmaterialien aus kolloidaler Lösung". [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=959856749.
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Allard, Dirk. "Strukturierte halbleitende Thiophene". [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=96993811X.
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Chirvase, Dana. "Electrical characterization of organic devices case study ; polythiophene-fullerene based solar cells /". [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=97400734X.
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Lowe, Jimmy K. L. "Synthesis, properties, and photolithography of polythiophene derivatives". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0019/NQ37728.pdf.
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Shuttle, Christopher G. "Recombination dynamics in polythiophene : fullerene solar cells". Thesis, Imperial College London, 2008. http://hdl.handle.net/10044/1/4652.
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Organic devices based on polymer:fullerene blend films are attracting extensiveinterest as low cost solar cells, with power conversion efficiencies over 5%.Improvements in performance are dependent on developing a better understanding ofthe pertinent loss processes. This in turn requires the ability to reliably determinecharge densities (n) and carrier lifetimes (?n) in real devices under standard operatingconditions. In this thesis, we address the recombination dynamics in organic solarcells based on blends of poly(3-hexylthiophene) (P3HT) and methanofullerene [6,6]-phenyl C61-butyric acid methyl ester (PCBM), P3HT:PCBM devices, one of the bestdevices to date, using both experimental and modelling studies. Initially, a drift-diffusion model was used to study the basic principles of solar celloperation, with particular focus on investigating the ?corrected photocurrent?, wherethe effects of dark injection are removed. We then have employed a series ofexperimental techniques ? including transient photovoltage and photocurrent,transient absorption spectroscopy and charge extraction ? to determine the carrierlifetimes and charge densities in standard annealed P3HT:PCBM devices underoperation. The results of our studies for a device under open-circuit conditions showthat the open-circuit voltage (Voc) is primarily governed by a trap dependentbimolecular recombination process. By applying charge extraction studies on devicesunder forward bias in the dark, we show that the dark current is also governed by thesame trap dependent bimolecular recombination mechanism which determines Voc. Based on the understanding of charge carrier dynamics at Voc and the forward biasdark current, a simple model has been developed to simulate ?light? current-voltage(J-V) curves. Despite the simplicity of this model, remarkably good agreement wasobserved with experimental J-V data.
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Anjos, Tânia Gomes. "Electrochemical and spectroelectrochemical studies on polythiophene derivatives". Thesis, Bangor University, 2006. https://research.bangor.ac.uk/portal/en/theses/electrochemical-and-spectroelectrochemical-studies-on-polythiophene-derivatives(d0af607b-ec5f-4137-aa29-7791600b6815).html.
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The polymerisation of dithienylethylenes (cis and trans 1,2-di(3-thienyl) ethylene, DTE-cis and DTE-trans), thiophene dithiolenes (4,5-dithiophen-3-yl-[1,3] dithiol-2-one, Th-3,3,4,5-di-thiophen-2-yl-[1,3]dithiol-2-one, Th-2,2,4-thiophen-3- yl-5-thiophen-2-yl-[1,3]dithiol-2-one, Th-2,3 and 4,5-di-(5-methyl-thiophen. -3-yl)- [1,3]dithiol-2-one, Th-3,3Me), and nickel dithiolenes (bis[1,2-di(3-thienyl)-1,2-ethenedithiolene] nickel tetrafluoroborate, Ni(Th-3,3)2 and bis[1,2-di(2-thienyl)-1,2-ethenedithiolene] nickel tetrafluoroborate, Ni(Th-2,2)2) was carried out and the resultant polymers were analysed by electrochemical and spectroelectrochemical methods. The voltammetric behaviour of the electropolymerised PDTE-cis and PDTEtrans suggested that polarons and bipolarons were produced upon oxidation. Nevertheless, the formation of a conducting state was not observed in the SNIFTIRS measurements. Upon I2 chemical doping, PDTE-cis and PDTE-trans showed increased stability in the doped state and the SNIFTIRS response of PDTE-trans, revealed similar IR characteristics to those of conductive polymers. The voltammetric and IR behaviour of the dithiolenes, PTh-3,3, PTh-2,2 and PTh-2,3 was similar to that of many conducting polymers. From the UV-Visible spectra of the neutral films it was determined that PTh-3,3, PTh-2,2 and PTh-2,3 have a bandgap of 2.04,2.30 and 2.18 eV, respectively. The electrochemical and SNIFTIRS results for PTh-3,3Me were noticeably different from the other dithiolene polymers revealing a poorly conductive polymer. The solid-state modification of PTh-3,3 to produce a new TTF derivatised polythiophene was carried out. The inclusion of TTF into the PTh-3,3 film was confirmed by voltammetry and IR data that also suggested that only partial modification of the polymer had occurred. The voltammetry of polyNi(Th-3,3)2 and polyNi(Th-2,2)2 showed a redox couple attributed to the electrochemistry of the nickel dithiolene centre, confirming the incorporation of the metal complex into the polymer. Whilst the SNIFTIR spectra of polyNi(Th-3,3)2 showed the characteristic features of metal dithiolenes, the IR behaviour of polyNi(Th-2,2)2 was more comparable to that of conducting polythiophenes. This result indicates that charge delocalisation in polyNi(Th-2,2) occurs through the Ni dithiolene sites disrupting the typical electroactivity of the dithiolene unit. For the polyNi(Th-3,3)2 films, the nickel dithiolene sites seem to be electronically isolated, preserving the aromaticity of the dithiolene system.
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Bodenstedt, Kurt. "Synthesis and Electron Transfer Studies of Supramolecular Triads". Thesis, University of North Texas, 2016. https://digital.library.unt.edu/ark:/67531/metadc849639/.
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This study expands the role of polythiophenes as an electron donating chromophore within energy harvesting milti-modular donor-acceptor systems. The polythiophene moiety would act as an electron donating spacer group between the donor and acceptor entities, viz., phenothiazine and fulleropyrrolidine, respectively, in the newly synthesized supramolecular triads. The triads 10-{[2,2';5',2"] terthiophene-5-fulleropyrrolidine} phenothiazine and 10-{[2,2'] bithiophene-5-fulleropyrrolidine} phenothiazine were synthesized and characterized through electrochemical and spectroscopic methods to ascertain their structural integrity. the componets of the triads were selected for their established redox parameters. Phenothiazine would act as a secondary donor and would facilitate hole-transfer from the polythiophene primary electron donor, due to its ease of oxidation and yield a long-lived charge separated state. Fulleropyrrolidine would act as an acceptor for ease of reductive capabilities and its ability to hold multiple charges. Finally, occurrence of photoinduced electron transferleading to the anticipated charge separated states is established from advanced transient spectroscopic techniques on these novel supramolecular systems.
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Williams, Gwion Owain. "Conducting polymers for use in supercapacitors : an electrochemical and spectroelectrochemical investigation into low bandgap thiophene derivatives". Thesis, Bangor University, 1999. https://research.bangor.ac.uk/portal/en/theses/conducting-polymers-for-use-in-supercapacitors--an-electrochemical-and-spectroelectrochemical-investigation-into-low-bandgap-thiophene-derivatives(08b98553-6f0c-42ad-9d48-1fc6274f2bbd).html.
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The following low bandgap conducting polymers have been prepared by electrochemical polymerisation of the corresponding monomers: poly-4Hcyclopenta[2,1-b; 3,4-b']dithiophene-4-one, (PCDT), poly-4-dicyanomethylene-4Hcyclopenta[2,1-b: 3,4-b']dithiophene (PCDM) and 6,8-di(2-cyano-2(2- thienyl))ethenyl-4(ethylenedioxy)-4H-cyclopenta[2,1-b; 3,4-b' ]dithiophene (PCET). The polymers were characterised by cyclic voltammetry, spectroelectrochemical studies and impedance measurements in order to assay their suitability as active materials in high power supercapacitors. The redox switching of the polymers from neutral to doped states and the charge capacity of the films was studied by cyclic voltammetry. The results showed that only PCDM and PCET underwent efficient p- and n- doping which is a prerequirement for type III supercapacitors. The electrochemical switching is accompanied by changes to the optical properties of the polymers which has been examined by spectroelectrochemical measurements. In situ UV-visible spectroscopy indicated that the polymers possessed a low bandgap (< 2 eV) and suggested that they adopt a quinoid structure during doping.
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Hampton, Mark D. "Polythiophene nanowires for use in organic electronic applications". Thesis, Cardiff University, 2012. http://orca.cf.ac.uk/45399/.
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The growth and formation of polythiophene nanowires (NWs) was studied using atomic force microscopy (AFM), UV-Vis spectroscopy, and X-ray diffraction (XRD). This was followed by the successful development of a novel technique for doping the nanowires, which led to the doped NWs being investigated in the active blend of organic photovoltaics (OPVs). Finally exploratory work was carried out on the feasibility of NWs as humidity and octylamine sensors, and as the semiconducting medium in water-gated organic field-effect transistors (WGOFETs). AFM revealed that the NWs were formed typically with heights of 1~10 nm, widths of 20~80 nm, and lengths exceeding 10 μm. The dimensions and the rate of growth of the NWs were affected by the polymer-solvent combination. XRD of the poly(3-hexylthiophene-2,5’-diyl) (P3HT) NWs suggested a structure that is in agreement with that of P3HT films found in the literature. There is vertical stacking of the alkyl-chains in the NWs, p- stacking of the thiophene chains along the long axis of the wires and the polymer back bones lie perpendicular to the length of the wire. It was seen that the NWs possessed a more compact alkyl chain stacking than the P3HT films. In situ thermal annealing of the NWs led to expansion of the alkyl chain stacking, an increase in domain sizes and a decrease in paracrstallinity. Poly(3,3”’-didodecyl-quarter-thiophene) (PQT-12) NWs displayed a meta-stable structure as cast, turning amorphous above 100°C, and recrystallising during cooling. Photoluminescence (PL) and combustion analysis provided indirect evidence to suggest successful intercalation of anthraquinone based dye molecules into P3HT and PQT-12 NWs during the growth phase, which is a novel and facile doping technique. Dye-intercalated P3HT-NW:PCBM OPVs showed an increase in power conversion efficiency (PCE) and open circuit voltage (VOC), and a decrease in short-circuit density (JSC) for one dye (2d) where the HOMO was deeper than that of both P3HT and PCBM. Octylamine and humidity chemiresistor sensors were successfully fabricated from P3HT NWs. The chemiresistors showed an increase in resistance upon exposure to as little as 3.6 ppm of octyl-amine, and a ~13-fold increase in resistance at 36 ppm. P3HT NW humidity sensors had a greater response than a P3HT film, with a 75-fold increase in conductance at 90% relative humidity (RH) compared to less than 25% increase for the film. Both film and P3HT NW devices had a threshold of 50% RH below which no significant change in conductance was measured. P3HT was successfully water-gated; NWs had a lower resistance than P3HT film water-gated organic field effect transistor (WGOFET) devices, while greater off-current was seen in the NW devices. P3HT-NW devices were found to be more sensitive than film devices indicated by a lower threshold voltage, and the electrochemical current to field-effect current, IOECT/IOFET, was lower for NWs compared to the film.
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Vijayakumar, Vishnu. "Highly oriented conducting polythiophene films for thermoelectric applications". Thesis, Strasbourg, 2020. http://www.theses.fr/2020STRAE004.
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Cette thèse concerne la fabrication de matériaux thermoélectriques (TE) à base de films minces orientés de polythiophènes (PBTTT). Le brossage à haute température produit des films minces de cristallinité et d’orientation contrôlées. Différentes méthodes de dopage avec des dopants tels F4TCNQ, F6TCNNQ et FeCl3 ont permis de fabriquer des films polymère conducteurs orientés aux propriétés TE anisotropes. Une combinaison de spectroscopie UV-vis-NIR polarisée et de MET donne accès à l’orientation et à la quantité de dopants intercalés dans les cristaux polymère. Le coefficient de diffusion du dopant est corrélé à la longueur des chaînes alkyls des polymères : les PBTTTs ayant des chaînes alkyls en C12 présentent les meilleurs propriétés TE en raison d’une diffusion rapide et efficace des dopants dans le polymère. Finalement, nous avons étudié l’effet du type de dopant (son électronégativité, sa taille) sur les propriétés TE des films. Le dopage de films orientés de C12-PBTTT avec FeCl3 permet d’atteindre des valeurs records de conductivité de 2.105 S/cm et des facteurs de puissance de l’ordre de 1 mW/mK2The aim of this thesis is to develop new polymeric thermoelectric (TE) materials based on oriented polythiophene (PBTTT) films. High-temperature rubbing produces oriented films of controlled orientation and crystallinity. Various doping methods with suitable dopants (F4TCNQ, F6TCNNQ and FeCl3) produced enhanced TE properties along the rubbing direction. A combination of polarized UV-Vis-NIR spectroscopy and TEM uncovered the amount and orientation of dopants intercalated in the crystals of PBTTT. The diffusion coefficient of dopants is correlated to the length of alkyl side chains : PBTTT with C12 side chains shows the best TE properties because of a fast and effective diffusion of dopants in the polymer films. Finally, we evaluated the impact of dopant (geometry, electronegativity) on the TE properties. Doping oriented PBTTT with FeCl3 helped reach record electrical conductivity of 2×105 S/cm and TE power factors of 1 mW/mK2
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Putnam, Daniel. "Investigation of degradation in polythiophene-fullerene based solar cells". [Ames, Iowa : Iowa State University], 2010. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1476338.
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Sarkar, Parantap. "The ceramidonine and perkin approaches to aromatic nanoribbons". Thesis, Bordeaux 1, 2012. http://www.theses.fr/2012BOR14555/document.
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Les nanorubans de graphène (NRGs) sont des matériaux prometteurs pour l'organique électronique, à mi chemin entre polymères conjugués et nanotubes de carbone. Deux approches différentes pour la synthèse de nanorubans aromatiques sont développées et évaluées. La première est fondée sur la formation de céramidonines par cyclisation d'arylamino-anthraquinones en milieu acide. Plusieurs tétraaza-arènes incorporant deux de ces unités sont obtenus, mais l'approche s'est uniquement avérée appropriée dans le cas de courts substrats. La seconde approche repose sur la condensation d'acides aryle-acétiques avec des formylarènes ou acides aryle-glyoxyliques, suivie soit de cyclo-deshydrogénations en présence de quinone, soit de deshydrodebromation catalysée par le palladium, pour donner des arenes carboxy-substitués allongés. La méthode impliquant la quinone s'avère limitée à des substrats suffisamment réactifs tels que des thiophènes et laisse envisager des poly(arènodithiophènes) en partie rigidifiés et carboxy-substitués. La catalyse au palladium s'avère plus générale, ouvrant des perspectives d'obtention d'une grande variété de rubans aux propriétés électroniques ajustablesGraphene nanoribbons (GNRs) are promising materials for organic electronics, as they bridge the gap betweensingle-stranded conjugated polymers and carbon nanotubes. Two different synthetic approaches to GNRs aredeveloped and evaluated. The first approach is based on the acid-promoted cyclisation of arylaminoanthraquinonesto ceramidonines. Tetraazaarenes with two ceramidonine units are obtained, but the approachis found to be appropriate only to such small systems. The second approach is based on the condensation ofarylacetic acids with arenecarboxaldehydes or arylglyoxylic acids, followed either by quinone-assistedoxidative cyclodehydrogenation or palladium-catalysed dehydrodebromination to yield carboxy-substitutedelongated arenes. The quinone-based variant is found to be limited to reactive substrates such as thiophenederivatives and offers the perspective of partially rigidified carboxy-substituted poly(arenodithiophenes). Thepalladium-based variant is found to be more general, opening the prospect of obtaining a variety of ribbontypestructures with tunable electronic properties
20
Oguz, Gulcan. "Pyrolysis Mass Spectrometric Analysis Of Copolymer Of Polyacrylonitrile And Polythiophene". Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605057/index.pdf.
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In the first part of this work, the structural and thermal characteristics of polyacrylonitrile, polyacrylonitrile films treated under the electrolysis conditions in the absence of thiophene, polythiophene and the mechanical mixture and a conducting copolymer of polyacrylonitrile/polythiophene have been studied by pyrolysis mass spectrometry technique.
The thermal degradation of polyacrylonitrile occurs in three stepsevolution of HCN, monomer, low molecular weight oligomers due to random chain cleavages are followed by cyclization and dehydrogenation reactions yielding crosslinked and unsaturated segments. Pyrolysis of the treated polyacrylonitrile films indicated decrease in the yields of monomer and oligomers, and increase in the amount of products stabilized by cyclization reactions were detected. Polythiophene degrades in two steps
the loss of the dopant and degradation of polymer backbone. The evolution profiles of polythiophene based products from polythiophene/polyacrylonitrile showed nearly identical trends with those recorded during the pyrolysis of pure polythiophene. However, evolution of HCN and the degradation products due to the homolytic cleavages of the polymer backbone continued through out the pyrolysis indicating a significant increase in their production. Furthermore, the yield of thermal degradation products associated with decomposition of the unsaturated cyclic imine segments decreased. A careful analysis of the data pointed out presence of mixed dimers confirming copolymer formation. In the second part of this work, a poly(acrylonitrile-co-butadiene) sample involving monomer units having quite similar molecular weights have been analyzed to investigate the limits of the pyrolysis mass spectrometry technique. Pyrolysis of aged poly(acrylonitrile-co-butadiene) indicated oxidative degradation of the sample. Keywords: conducting copolymer, polyacrylonitrile, polythiophene, polybutadiene, direct pyrolysis mass spectrometry
21
OLINGA, EDSON THOMAS. "Synthese et etude de copolymeres comportant des sequences de polythiophene". Université Louis Pasteur (Strasbourg) (1971-2008), 1992. http://www.theses.fr/1992STR13192.
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Des copolymeres originaux sequences ou greffes polystyrene-polythiophene (ps-pt) ou polymethacrylate de methyle (pmma-pt) ont ete synthetises en 2 etapes. Dans une premiere etape on a fixe des groupements thiophene ou bromothiophene a l'extremite, ou le long de chaines de polystyrene ou de pmma. Dans une deuxieme etape ces polymeres fonctionnalises sont mis en presence de thiophene et de chlorure ferrique (fecl#3). Il en resulte la formation simultanee de copolymeres et d'homopolythiophene; un fractionnement permet d'isoler des copolymeres. Des etudes physicochimiques de solutions des copolymeres (ps-pt ou pmma-pt) par gpc, diffusion de la lumiere et viscosimetrie, montrent que ces derniers sont fortement agreges lorsque le nombre d'unites thiophene conjugues est superieur a 6-7. Une etude de la composition des copolymeres sequences ps-pt en fonction de la masse moleculaire de la sequence de ps, montre que la longueur de la sequence de pt augmente avec celle de la sequence de ps jusqu'a une valeur lilite de 100000. L'etude des copolymeres par spectroscopie uv/visible, ir et raman montre que les sequences de pt presentent peu de defauts et sont comparables aux meilleurs homopolythiophenes electrochimiques. Les copolymeres ps-pt ont ete dope p en solution par fecl#3 et leurs spectres d'absorption optique ont ete etudies. Toutefois un large exces de fecl#3 est necessaire pour obtenir un dopage total du copolymere. La pyrolyse partielle des copolymeres a 400c sous atmosphere d'argon donne un film de pt pur dont la morphologie depend de l'epaisseur du film initial. La conductivite du copolymere dope par fecl#3 est de l'ordre de 10##4 s/cm et varie peu avec la frequence entre le continu et 10#4 hz, alors que celle d'un film de pt issu de la pyrolyse du meme copolymere et dope par fecl#3 est voisine de 60 s/cm
22
DANESH, CAMERON DEAN. "SURFACTANT FORMULATIONS FOR WATER-BASED PROCESSING OF A POLYTHIOPHENE DERIVATIVE". DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/1058.
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Conjugated polymers are semiconducting materials that are currently being researched for numerous applications from chemical and biological sensors to electronic devices, including photovoltaics and transistors. Much of the novel research on conjugated polymers is performed in academic settings, where scientists are working to prepare conjugated polymers for commercially viable applications. By offering numerous advantages, inherent in macromolecular materials, conjugated polymers may hold the key to cheap and environmentally friendly manufacturing of future electronic devices. Mechanical flexibility, and solvent-based coating processes are two commonly cited advantages. Transitions in the backbone conformation of polythiophenes (PT) in organic solvents have been widely observed to influence thin-film morphology. However, conformational transitions of water-soluble PT derivatives, with respect to their intramolecular versus intermolecular origin, remain largely obscure. Here, conformational transitions of a water- soluble polythiophene in aqueous ionic surfactants are investigated by means of Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), polarizing optical microscopy (POM), ultraviolet-visible (UV-Vis) absorption and fluorescence spectroscopy, and various X-ray scattering techniques. As-prepared complexes exist as stable hydrogels. Upon dilution, a significant time-dependent chromism occurs spontaneously. A coil-to-rod conformational transition is identified in this mechanism and verified using small-angle x-ray scattering (SAXS). Study into the corresponding kinetics demonstrates an inverse first-order rate law. It is found that the conformational transition is thermally reversible and concentration-independent. The critical transition temperature is largely dependent on the surfactant formulation. A theoretical model is presented to explain this new phenomenon and the mechanisms behind its influence on the optoelectronic and solid-state morphological properties. A relationship between the dilute-solution processing with surfactants and the final properties of the system is substantiated.
23
Ellinger, Stefan. "Neue Synthesestrategie zu alpha- und alpha,omega-substituierten Oligo- und Polythiophenen und deren Selbstorganisation". [S.l. : s.n.], 2006. http://nbn-resolving.de/urn:nbn:de:bsz:289-vts-57926.
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Dalgakiran, Sibel. "Design and electrochemical characterizaton of novel functionalized polythiophene and polysiloxane derivatives". Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/42226.
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Metal-containing conducting polymers are a new and interesting class of materials that
combine some of the redox properties of the conducting polymers and metal ions. In metal-containing
conjugated polymers, there are several possible arrangements of the metal group
relative to the backbone. This research focuses on the development of novel thiophene
derivatives, with various side groups using different synthetic approaches and electrochemical
polymerization. The resulting polymers could be excellent candidates for chemical sensors, solar
cells, photoactive molecular devices and capacitors.
Thiophene-based polymers containing η⁶-(haloarene)-η⁵-cyclopentadienyliron(II)
hexafluorophosphate or ferrocene moieties were synthesized. Thiophene monomers which
contained organoiron complexes were successfully polymerized using condensation
polymerization and electropolymerization. The monomers and their precursors were
characterized through nuclear magnetic resonance spectroscopy, infrared spectroscopy, cyclic
voltammetry and electrochemical impedance spectroscopy. The thermal properties were studied
with thermogravimetric analysis and differential scanning calorimetry.
A novel series of functionalized thiophenes incorporating naphthol, coumarin and pyrene
pendants were synthesized by Steglich esterification in the presence of DCC/DMAP and the
synthesized monomers were electrochemically deposited onto glassy carbon and carbon fibre
microelectrodes as active electrode materials. Another series was prepared with thiophenes using
pendant terpyridine groups of varying functionality. The electrochemical impedance
measurements were performed on surface-modified electrodes. Variation of capacitance values
was explained according to the different fluorophore groups attached to the thiophene as well as
the different substrates. The fluorescence behaviours and the surface morphological analysis
were explained in detail.
Additionally, using organoiron-mediated nucleophilic aromatic substitution, a number of
allylamine-containing organoiron complexes were prepared. These materials were further
hydrosilated with methyldiethoxyhydrosilane to generate cationic organoiron siloxanes and
ferrocene-containing siloxane complexes. In situ cleavage of the ethoxy groups followed by the
addition of H₂SO₄ resulted in the formation of polymeric materials. The synthesized polymers
were individually blended with PAN/DMF matrix to form composite thin films. The films
indicated porous surface morphology, increasing the surface activity.
25
Ak, Metin. "Synthesis Of Polythiophene And Polypyrrole Derivatives And Their Application In Electrochromic Devices". Phd thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12608070/index.pdf.
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Different substituted thiophene and pyrrole monomers namely hexamethylene (bis-3-thiopheneacetamide) (HMTA), N-(4-(3-thienylmethylene)-oxycarbonylphenyl)maleimide (MBThi), 2,4,6-Tris-(4-pyrrol-1-yl-phenoxy)-[1,3,5]triazine (TriaPy), 2,4,6-Tris-(thiophen-3-ylmethoxy)-[1,3,5] triazine (TriaTh), and N-(2-(thiophen-3-yl)methylcarbonyloxyethyl) maleimide (NMT) were synthesized. The chemical structures of the monomers were characterized by Nuclear Magnetic Resonance (1H-NMR and 13C-NMR) and Fourier Transform Infrared (FTIR) Spectroscopies. Electrochemical behavior of the monomers in the presence and absence of comonomers were studied by cyclic voltammetry. Subsequently, monomers were homopolymerized and copolymerized via electrochemical methods and the resultant polymers were characterized by FTIR, Scanning Electron Microscopy (SEM) and conductivity measurements.
Second part of the study was devoted to investigate one of most interesting property of conducting polymers, the ability to switch reversibly between the two states of different optical properties, &ldquoelectrochromism&rdquo
. In recent years there has been a growing interest in application of conducting polymers in electrochromic devices. Thus, electrochromic properties of the synthesized conducting polymers were investigated by several methods like spectroelectrochemistry, kinetic and colorimetry studies. Spectroelectrochemistry experiments were performed in order to investigate key properties of conjugated polymers such as band gap, maximum absorption wavelength, the intergap states that appear upon doping and evolution of polaron and bipolaron bands. Switching time and optical contrast of the homopolymers and copolymers were evaluated via kinetic studies. Results implied the possible use of these materials in electrochromic devices due to their good electrochromic properties.
26
Fritsch, Martin [Verfasser]. "Polyfluorene und Polythiophene für das Umwickeln von einwandigen Kohlenstoff-Nanoröhren / Martin Fritsch". Wuppertal : Universitätsbibliothek Wuppertal, 2016. http://d-nb.info/1124474005/34.
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Varene, Erwan [Verfasser]. "Exciton and Polaron Dynamics in Thin Oligo- and Polythiophene Films / Erwan Varene". Berlin : Freie Universität Berlin, 2013. http://d-nb.info/1036872521/34.
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Heimonen, Johanna. "Synthesis of a polar conjugated polythiophene for 3D-printing of complex coacervates". Thesis, Linköpings universitet, Laboratoriet för organisk elektronik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-177396.
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The aim of this thesis was to synthesize a functionalized polar conjugated polythiophene that could be (3D-) printed into form-stable structures for bio-interfacing. The material design rationale aimed for a water-processable polymer that had the capability of electronic and ionic conduction, by using a thiophene backbone and oligoethylene side chains. Functionalization of the oligoethylene side chains with carboxylate groups created a polyanion, which allowed for a bio-inspired approach to combine printability and form-stability through formation of complex coacervates. The synthesis of the conjugated monomer and polymer was optimized to provide a more sustainable and material efficient synthesis route. Combined structural analysis with 1H-NMR, FT-IR and UV-vis revealed successful synthesis of the target polymer. Spectro electrochemistry revealed that the polymer was optically and electrochemically active in both the protected and deprotected form. The obtained material is processable from water, and initial tests revealed that crosslinking can be achieved through formation of acid dimers, ionic crosslinks with Ca2+ ions and complex coacervation with a polycation.Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet
29
Marinelli, Martina <1991>. "New functional polythiophene based materials: fine-tuning of photovoltaic or chiroptical properties". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amsdottorato.unibo.it/9353/1/Marinelli_Martina_Tesi.pdf.
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There is a remarkable level of interest in the development of π-conjugated polymers (ICPs) which have been employed, thanks to their promising optical and electronic properties, in numerous applications including photovoltaic cells, light emitting diodes and thin-film transistors. Although high power conversion efficiency can be reached using poly(3-alkylthiophenes) (P3ATs) as electron-donating materials in polymeric solar cells of the Bulk-Heterojunction type (BHJ), their relatively large band gap limits the solar spectrum fraction that can be utilized.
The research work described in this dissertation thus concerns the synthesis, characterization and study of the optical and photoactivity properties of new organic semiconducting materials based on polythiophenes. In detail, various narrow band gap polymers and copolymers were developed through different approaches and were characterized by several complementary techniques, such as gel permeation chromatography (GPC), NMR spectroscopy, thermal analyses (DSC, TGA), UV-Vis/PL spectroscopy and cyclic voltammetry (CV), in order to investigate their structural and chemical/photophysical properties. Moreover, the polymeric derivatives were tested as active material in air-processed organic solar cells.
The activity has also been devoted to investigate the behavior of polythiophenes with chiral side chain, that are fascinating materials capable to assume helix supramolecular structures, exhibiting optical activity in the aggregated state.
30
Zhang, Fapei. "Role of polythiophene- based interlayers from electrochemical processes on organic light-emitting diodes". Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2004. http://nbn-resolving.de/urn:nbn:de:swb:14-1075975979500-25235.
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In this work, well-defined and stable thin films based on polythiophene and its derivative, are employed as the hole-injection contact of organic light-emitting diodes (OLED). The polymer films are obtained by the electropolymerization or the electrochemical doping/dedoping of a spin-coated layer. Their electrical properties and energetics are tailored by electrochemical adjustment of their doping levels in order to improve the hole-injection from the anode as well as the performance of small molecular OLEDs. By using dimeric thiophene and optimizing the electrodeposition parameters, a thin polybithiophene (PbT) layer is fabricated with well-defined morphology and a high degree of smoothness by electro-polymerization. The introduction of the semiconducting PbT contact layer improves remarkably the hole injection between ITO anode and the hole- transport layer (NPB) due to its favourable energetic feature (HOMO level of 5.1 eV). The vapor-deposited NPB/Alq3 bilayer OLEDs with a thin PbT interlayer, show a remarkable reduction of the operating voltage as well as enhanced luminous efficiency compared to the devices without PbT. Investigations have also been made on the influence of PbT thickness on the efficiency and I-V feature as well as device stability of the OLED. It is demonstrated that the use of an electropolymerization step into the production of vapor deposited molecular OLED is a viable approach to obtain high performance OLEDs. The study on the PbT has been extended to poly(3,4-ethylenedioxythiophene) (PEDT) and the highly homogenous poly(styrenesulfonate) (PSS) doped PEDT layer from a spin-coating process has been applied. The doping level of PEDT:PSS was adjusted quantitatively by an electrochemical doping/dedoping process using a p-tuoluenesulfonic acid containing solution, and the redox mechanism was elucidated. The higher oxidation state can remain stable in the dry state. The work function of PEDT:PSS increases with the doping level after adjusting at an electrode potential higher than the value of the electrochemical equilibrium potential (Eeq) of an untreated film. This leads to a further reduction of the hole-injection barrier at the contact of the polymeric anode/hole transport layer and an ideal ohmic behavoir is almost achieved at the anode/NPB interface for a PEDT:PSS anode with very high doping level. Molecular Alq3-based OLEDs were fabricated using the electrochemically treated PEDT:PSS/ITO anode, and the device performance is shown to depend on the doping level of polymeric anode. The devices on the polymer anode with a higher Eeq than that for the unmodified anode, show a reduction of operating voltage as well as a remarkable enhancement of the luminance. Furthermore, it is found that the operating stability of such devices is also improved remarkably. This originates from the removal of mobile ions such as sodium ions inside the PEDT:PSS by electrochemical treatment as well as the planarization of the ITO surface by the polymer film. By utilizing an Al/LiF cathode with an enhanced electron injection and together with a high Eeq- anode, a balanced injection and recombination of hole and electron is achieved. It leads to a further reduction of the operating voltage and to a drastic improvement of EL efficiency of the device as high as 5.0 cd/A. The results demonstrate unambiguously that the electrochemical treatment of a cast polymer anode is an effective method to improve and optimize the performance of OLEDs. The method can be extended to other polythiophene systems and other conjugated polymers in the fabrication of the OLEDs as well as organic transistors and solar cells.
31
Tarkuc, Simge. "Synthesis And Characterization Of A New Soluble Polythiophene Derivative And Its Electrochromic Application". Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607993/index.pdf.
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The Knorr-Paal reaction of 1,4-di(2-thienyl)-1,4-butanedione with aniline to yield 1-phenyl-2,5-di(2-thienyl)-1H-pyrrole (PTP) was performed in the presence of catalytical amounts of p-toluenesulfonic acid (PTSA). Chemical polymerization of the monomer yielded a soluble polymer. Structures of both the monomer and the polymer were investigated by Nuclear Magnetic Resonance (1H and 13C NMR) and Fourier Transform Infrared (FTIR) Spectroscopy. The average molecular weight of the chemically synthesized polymer was determined by Gel Permeation Chromatography (GPC) as
Mn = 7.2 x 103 g/mol. The electrochemical oxidative polymerization of PTP was carried out via potentiodynamic electrolysis in the presence of LiClO4, NaClO4 (1:1) being the supporting electrolyte in acetonitrile. Electrochemical copolymerization of PTP with 3,4-ethylenedioxythiophene (EDOT) was carried out in acetonitrile (ACN)/ NaClO4/LiClO4 (0.1M) solvent-electrolyte couple system via potentiodynamic electrolysis. Cyclic voltammetry was used to investigate electrochemical behavior of the monomer and redox reactions of conducting polymers. Conductivities of films of the polymers were measured by four-probe technique. Surface morphologies of the films were investigated by Scanning Electron Microscope (SEM). Electrochromic properties of the conducting polymers were investigated via spectroelectrochemistry, kinetic and colorimetry studies. Spectroelectrochemical analysis of P(PTP) revealed electronic transitions at 413, 600 and 900 nm corresponding to π
-&
#960
* transition, polaron, and bipolaron band formations, respectively. The spectroelectrochemical behavior of the P(PTP-co-EDOT) in comparison to those of the respective homopolymers revealed solid evidence of copolymerization based upon the differences in the spectral signatures. Switching time of the polymers was evaluated by kinetic studies upon measuring the percent transmittance (%T) at the maximum contrast point. As an application, absorption/transmission type electrochromic devices with ITO/homopolymer(copolymer)/gel electrolyte/PEDOT/ITO configuration was constructed, where homopolymer (copolymer) and PEDOT functioned as the anodically and the cathodically coloring layers, respectively. Spectroelectrochemistry, switching ability and open circuit memory of the devices were investigated. The results revealed that these devices have good switching times, reasonable contrasts and optical memories.
32
Zhang, Fapei. "Role of polythiophene- based interlayers from electrochemical processes on organic light-emitting diodes". Doctoral thesis, Technische Universität Dresden, 2003. https://tud.qucosa.de/id/qucosa%3A24300.
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In this work, well-defined and stable thin films based on polythiophene and its derivative, are employed as the hole-injection contact of organic light-emitting diodes (OLED). The polymer films are obtained by the electropolymerization or the electrochemical doping/dedoping of a spin-coated layer. Their electrical properties and energetics are tailored by electrochemical adjustment of their doping levels in order to improve the hole-injection from the anode as well as the performance of small molecular OLEDs. By using dimeric thiophene and optimizing the electrodeposition parameters, a thin polybithiophene (PbT) layer is fabricated with well-defined morphology and a high degree of smoothness by electro-polymerization. The introduction of the semiconducting PbT contact layer improves remarkably the hole injection between ITO anode and the hole- transport layer (NPB) due to its favourable energetic feature (HOMO level of 5.1 eV). The vapor-deposited NPB/Alq3 bilayer OLEDs with a thin PbT interlayer, show a remarkable reduction of the operating voltage as well as enhanced luminous efficiency compared to the devices without PbT. Investigations have also been made on the influence of PbT thickness on the efficiency and I-V feature as well as device stability of the OLED. It is demonstrated that the use of an electropolymerization step into the production of vapor deposited molecular OLED is a viable approach to obtain high performance OLEDs. The study on the PbT has been extended to poly(3,4-ethylenedioxythiophene) (PEDT) and the highly homogenous poly(styrenesulfonate) (PSS) doped PEDT layer from a spin-coating process has been applied. The doping level of PEDT:PSS was adjusted quantitatively by an electrochemical doping/dedoping process using a p-tuoluenesulfonic acid containing solution, and the redox mechanism was elucidated. The higher oxidation state can remain stable in the dry state. The work function of PEDT:PSS increases with the doping level after adjusting at an electrode potential higher than the value of the electrochemical equilibrium potential (Eeq) of an untreated film. This leads to a further reduction of the hole-injection barrier at the contact of the polymeric anode/hole transport layer and an ideal ohmic behavoir is almost achieved at the anode/NPB interface for a PEDT:PSS anode with very high doping level. Molecular Alq3-based OLEDs were fabricated using the electrochemically treated PEDT:PSS/ITO anode, and the device performance is shown to depend on the doping level of polymeric anode. The devices on the polymer anode with a higher Eeq than that for the unmodified anode, show a reduction of operating voltage as well as a remarkable enhancement of the luminance. Furthermore, it is found that the operating stability of such devices is also improved remarkably. This originates from the removal of mobile ions such as sodium ions inside the PEDT:PSS by electrochemical treatment as well as the planarization of the ITO surface by the polymer film. By utilizing an Al/LiF cathode with an enhanced electron injection and together with a high Eeq- anode, a balanced injection and recombination of hole and electron is achieved. It leads to a further reduction of the operating voltage and to a drastic improvement of EL efficiency of the device as high as 5.0 cd/A. The results demonstrate unambiguously that the electrochemical treatment of a cast polymer anode is an effective method to improve and optimize the performance of OLEDs. The method can be extended to other polythiophene systems and other conjugated polymers in the fabrication of the OLEDs as well as organic transistors and solar cells.
33
Redeker, Neil. "MORPHOLOGY AND CONFORMATION OF POLYTHIOPHENE DERIVATIVES IN ANISOTROPIC CORE-SHELL NANOCOMPOSITES AND SOLUTION". DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/1144.
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Conjugated semiconducting polymers have garnered substantial interest in recent years due to the potential for use in various applications, particularly in the field of electronic devices such as photovoltaic cells and light emitting diodes. Conjugated polymers offer numerous advantages in these applications, including low cost and high flexibility, but electronic devices based on these materials are currently limited by poor performance. Because of these limitations, increased focus has been placed on improving conjugated polymers for use in commercially viable products. Here, a novel core shell hybrid nanocomposite based on anisotropic zinc oxide nanowires and a side-chain functionalized polythiophene is reported. This nanocomposite exhibits confirmed covalent side-on linkage between the polymer and the nanowires, and the crystalline, thermal and photophysical properties of the nanocomposite are investigated, revealing elongated conjugation length in the polymer backbone, increased crystallinity and thermal stability and rapid charge transfer. Additionally, the conformational transitions of side-chain functionalized polythiophenes are investigated in dilute solution through the use of ultraviolet-visible absorption spectrophotometry. A coil-to-rod conformational transition is identified, and is found to be induceable through temperature and solvent changes. Study into the kinetics of the transition reveals a first-order rate law, and the effects of polymer structure on the conformational transition are substantiated.
34
Dang, Xuan Dung. "Electrosynthesis and characterization of thin copolymer films based on pyrrole and thiophene derivatives". Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2005. http://nbn-resolving.de/urn:nbn:de:swb:14-1125491701029-31683.
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Die Copolymerisation wurde mit dem Ziel untersucht, polymere Materialien zu synthetisieren, die die individuellen Eigenschaften der entsprechenden Homopolymere kombinieren. Die Dissertation konzentrierte sich auf die Elektrosynthese und Charakterisierung von leitfähigen Copolymerfilmen auf Basis von Pyrrol- und Thiophenderivaten. Mit einer Reihe von elektrochemischen, spektroskopischen und mikroskopischen Untersuchungsmethoden (Zyklovoltammetrie, elektrochemische Impedanz-spektroskopie, photoelektrochemische Spektroskopie, Elektrospray- Ionisations-Massenspektroskopie, Festkörper- NMR, Raman-Spektroskopie, Thermoanalyse und Rasterelektronenmikroskopie) wurde die Bildung echter Copolymere von Pyrrol mit Bithiophen und von 3-Methylthiophen mit Ethyl-3-thiophenazetat nachgewiesen. Die analytischen Ergebnisse bestätigen, dass Random- Copolymere und keine Block-Copolymere gebildet wurden. Die elektronischen und strukturellen Eigenschaften der Copolymerfilme liegen zwischen denen der jeweiligen Homopolymere und sind abhängig von der Copolymerzusammensetzung. Insbesondere die Halbleiterparameter der Copolymerfilme von Pyrrol mit Bithiophen wie Flachband-Potential, Bandlücken-Energie und Ladungsträgerdichte verschieben sich von denen des reinen Polypyrrols bis zum Polybithiophen, wenn der Gehalt an Bithiophen im Copolymerfilm vergrößert wird. Diese Parameter sind einstellbar durch Variation des Monomerverhältnisses oder des Polymerisationspotentials. Außerdem konnten die strukturellen und elektronischen Eigenschaften des funktionalisierten Polymers Ethyl-3-thiophenazetat durch Copolymerisation mit 3-Methylthiophen deutlich verbessert werden. Die synthetisierten leitfähigen Copolymerfilme können in der Sensorik Anwendung findenThe copolymerization has been studied as a new strategy to synthesize polymer materials by combining interesting properties of the respective homopolymers. In this dissertation, the work focused on the electrosynthesis and characterization of conducting copolymer films based on pyrrole and thiophene derivatives. A variety of electrochemical, spectroscopic and microscopic techniques such as cyclic voltammetry, electrochemical impedance and photoelectrochemical spectroscopy, electrospray ionization mass spectroscopy, solid state NMR and Raman spectroscopy, thermal analysis and scanning electron microscopy supported the formation of true copolymers of pyrrole with bithiophene and 3-methylthiophene with ethyl-3-thiophene acetate. The analytical results exhibited that random copolymers were produced rather than block copolymers. The electronic and structural characteristics of the copolymer films were intermediate between those of the respective homopolymers and they were dependent on the copolymer composition. In particular, the semiconducting parameters of the copolymer films of pyrrole and bithiophene such as flat band potential, band gap energy and charge carrier density shifted from those of polypyrrole to polybithiophene with increasing bithiophene content of the copolymer films. Such parameters were controlled precisely by alternating either the monomer ratio or the polymerization potential. In addition, the morphological and electronic properties of the functionalized polymers of ethyl-3-thiophene acetate were increased significantly by copolymerization with 3-methylthiophene. The obtained conducting copolymer films were able to be applied in the field of sensoric
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Yang, Li. "Terephthalate-Functionalized Conducting Redox Polymers for Energy Storage Applications". Doctoral thesis, Uppsala universitet, Nanoteknologi och funktionella material, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-304628.
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Organic electrode materials, as sustainable and environmental benign alternatives to inorganic electrode materials, show great promise for achieving cheap, light, versatile and disposable devices for electrical energy storage applications. Conducting redox polymers (CRPs) are a new class of organic electrode materials where the charge storage capacity is provided by the redox chemistry of functional pendent groups and electronic conductivity is provided by the doped conducting polymer backbone, enabling the production of energy storage devices with high charge storage capacity and high power capability. This pendant-conducting polymer backbone combination can solve two of the main problems associated with organic molecule-based electrode materials, i.e. the dissolution of the active material and the sluggish charge transport within the material. In this thesis, diethyl terephthalate and polythiophenes were utilized as the pendant and the backbone, respectively. The choice of pendant-conducting polymer backbone combination was based on potential match between the two moieties, i.e. the redox reaction of terephthalate pendent groups and the n-doping of polythiophene backbone occur in the same potential region. The resulting CRPs exhibited fast charge transport within the polymer films and low activation energies involved charge propagation through these materials. In the design of these CRPs an unconjugated link between the pendant and the backbone was found to be advantageous in terms of the polymerizability of the monomers and for the preservation of individual redox activity of the pendants and the polymer chain in CRPs. The functionalized materials were specifically designed as anode materials for energy storage applications and, although insufficient cycling stability was observed, the work presented in this thesis demonstrates that the combination of redox active functional groups with conducting polymers, forming CRPs, shows promise for the development of organic matter-based electrical energy storage materials.
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Claus, Ron. "Ferrocenylsubstituierte Thiophene". Doctoral thesis, Universitätsbibliothek Chemnitz, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-82047.
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Ferrocenylsubstituierte Thiophene:
Synthese, Charakterisierung und Polymerisation
Technische Universität Chemnitz, Fakultät für Naturwissenschaften
Dissertation 2011, 140 Seiten
Die Vorliegende Arbeit beschäftigt sich mit der Synthese und dem Reaktionsverhalten von metallocenylhaltigen Thiophenen. Dabei wurden die erhaltenen Metallocenylthiophene mittels Eisen(III)salzen oxidativ polymerisiert und copolymerisiert. Für eine gezielte Synthese von polymeren Verbindungen wurden oligomere Modellverbindungen dargestellt und die erhaltenen Ergebnisse auf eine vielfältig Funktionalisierung in 2- und/oder 5-Position der Thiophenmonomere angewendet. Die somit erhaltenen neuen Monomere lassen verschiedene Polymerisationen und Copolymerisationen, z. B. über eine Negishi-Kreuzkupplungsreaktion zu. Die somit erhaltenen Polymere und Copolymere liegen in der neutralen Form vor und weisen eine regioselektive Kopf-Schwanz-Verknüpfung auf. Es ist damit ein verarbeitbares Polymer zugänglich, welches sowohl im oxidierten Zustand als auch im neutralen Zustand als Polymer-CNT-Hybridmaterial Leitfähig ist.
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Ozyurt, Funda. "Synthesis And Electrochromic Properties Of A Multichromic, Conducting, Soluble Polythiophene Derivative And Its Copolymer". Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/2/12610630/index.pdf.
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A new polythiophene derivative, poly-2,3-bis(4-tert-butylphenyl)-5,8-bis(4-hexylthiophen-2-yl)quinoxaline PHTQ was synthesized by both chemical and electrochemical polymerization and its electrochemical properties were reported. The monomer was electrochemically polymerized in the presence of tetrabutylammonium hexafluorophosphate(TBAPF6) as the supporting electrolyte in dichloromethane-acetonitrile (5:95, v:v). Nuclear magnetic resonance spectroscopy (1H-NMR, 13C-NMR) was utilized for the characterization of the monomer and the soluble polymer. The polymer was further characterized by Gel Permeation Chromatography (GPC). Spectroelectrochemistry and switching ability of the polymer were investigated by UV&ndashvis spectrophotometer and cyclic voltammetry. The polymer revealed three distinctive colors upon doping which indicated that the polymer is multichromic. Tert-butyl group on the pendant phenyl rings and hexyl groups on thiophene enhanced the solution processability of the electrochromic polymer. The electrochemical and spectral properties of the chemically synthesized polymer were investigated via spray coating on ITO glass slides. Electrochemical copolymerization of 2,3-bis(4-tert-butylphenyl)-5,8-bis(4-hexylthiophen-2-yl) quinoxaline (HTQ) with 3,4-ethylenedioxythiophene(EDOT) was performed to fulfill a strategy in achieving fine-tuned electrochromic properties. The copolymer, P(HTQ-co-EDOT) was characterized via detailed studies of cyclic voltammetry and spectroelectrochemistry. Band gap (Eg) of the copolymer was calculated as 1.4 eV and showed 34 % optical contrast with switching times less than 1 second.
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Ebadian, Soheil. "Design and fabrication of polythiophene-based organic photovoltaic devices on glass and plastic substrate". Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/12120.
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This thesis reports our various experimental and theoretical work on design and fabrication of organic bulk hetero junction photovoltaic devices based on P3HT:PCBM blends, fabricated on glass and plastic. This work compares several measured characteristics of these devices so as to bring insight on the effect of annealing and regioregularity of the polymer on the photovoltaic characteristic of the devices. More specifically, we present the fabrication method of P3HT:PCBM organic photovoltaic devices on glass and plastic. By comparing the low and high regioregular (RR) P3HT samples used for fabrication of solar cells, we conclude that devices based on higher RR P3HT are more prone to degradation. The low RR device, on the other hand, demonstrates an increase in the hole mobility in post-annealed conditions as thermal annealing causes a more effective π - π stacking. This leads to unchanged or even higher power conversion efficiency (PCE) of the devices with lower regioregularity after thermal annealing. For the same reason, the low RR devices are found to be more stable during a four month degradation analysis while the efficiency of high RR device decreases drastically in the same period of time.
We also present a method for reducing the roughness of polyethylene terephthalate (PET) substrates for fabrication of organic photovoltaics. Using PEDOT:PSS we have been able to reduce the roughness drastically and have increased the yield by decreasing the possibility of top-bottom electrode short circuit. In this method the PEDOT:PSS is deposited on the substrate in a 2-step method that makes the substrate smoother and more uniform before P3HT:PCBM deposition.
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Lai, Kevin. "The synthesis of novel polythiophene and investigation of their physio-chemical and biosensor properties". Thesis, Kingston University, 2009. http://eprints.kingston.ac.uk/20419/.
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Poly(3-alkylthiophene)s (P3ATs) are considered to be an important class of electro chromic materials because of their reasonably high solubility, convenient processability and environmental stability. The adhesion of electrochromic polymers coated on a conducting substrate is a significant factor affecting the durable colour-changing life of electro chromic devices, Traditional electrochromic coatings on indium-tin oxide (ITO) glass electrodes have poor lifetimes due to the incompatibility between polymers and inorganic substrates. However, providing a bonding network between organic electrochromics and ITO glass is an efficient method to increase the adhesion and also extend the service life, and this research used Suzuki-Miyaura coupling ofN¬(3-methoxysilylpropyl)pyrrole (3TPP) onto poly(3-hexylthiophene) (P3HT) as a precursor of the sol-gel reaction. The Si-O-Metal network produced between the siloxane groups and the metal oxide after the sol-gel reaction served to enhance the adhesion of the poly(3-hexyIthiophene) onto ITO glass. With this stronger bonding, the colour-changing service life was found to be extended considerably by the observation of repeated colour-changing tests over a period of time. In addition, the electro-optic and electrochemical properties of copolymers with various substituted molar ratios of 3TPP on P3HT were investigated by cyclic voltammetry and UV -visible spectroscopy. The 1t 1t* transition energy ofP3HT was augmented by increasing the degree of bromo-substitution and diminished again after substituting with 3TPP. Hysteresis in the electro chromic switching was more noticeable with increased bromo-substitution on the P3HT, but it decreased when 3TPP was attached to the thiophene rings. The concentration of urea in serum samples is used to monitor diabetes and also to indicate the onset of kidney failure and liver malfunction, A potentiometric biosensor was found to be a convenient detector to quantify the urea concentration, because of the clear rest potential variation when urea hydrolysed by urease (Urs) resulted in a p[OHl change in the analyte. Other workers have investigated the immobilisation of enzymes on polypyrroles due to their high biocompatibility. However, ope of the drawbacks can be the uneven surface of polypyrrole film, which may cause the detection to be insensitive. In this project, the copolymer poly«3-hexyIthiophene)-co-(3- thiopheneacetic acid)) (P(3HT-co-3TAA)) was synthesised via iron (III) chloride polymerisation, and characterised by IH-NMR and FT-IR spectrometry, Urease was immobilised on the smooth surface of this copolymer via a carbodiimide coupling reaction provided by N-(3-dimethylaminopropyl)-N' -ethyl-carbodiimidehydrochloride (EDC) and N-hydroxysuccinimide (NHS). The electrochemical behaviour of Urs/P(3HT-co-3TAA)/ITO glass electrode was investigated by cyclic voltammetry. The enzyme activity of Urs/P(3HT-co-3TAA)/ITO glass electrode was confirmed by spectrophotometric assay. Potentiometric response studies also indicated this electrode could detect the concentration of urea in aqueous solution at a level of approximately 5 millimoles (mM).
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Zhang, Rong. "Preparation, electroactive properties and field controlled microwave transmission of polythiophene based conducting polymer composites". Thesis, University of Sheffield, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.398610.
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Boufflet, Pierre. "Fluorination as a tool for controlling properties, molecular order and functionality of polythiophene derivatives". Thesis, Imperial College London, 2016. http://hdl.handle.net/10044/1/55242.
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In this work, we explore the uses of fluorination in the context of π-conjugated polymers. Using extensively studied model systems such as poly(3-hexylthiophene) (P3HT) and poly(2,5-bis(3- alkylthiophen-2-yl)thieno[3,2-b]thiophene) (PBTTT), we are able to probe the influence of thiophene fluorination on the electronic structure and thin-film morphology, two defining aspects of organic semiconductor performance in electronic devices such as organic field effect transistors (OFET). Experimental data obtained from Ultraviolet photoelectron, UV-Visible and Raman spectroscopy along with differential scanning calorimetry, atomic force microscopy and X-ray diffraction suggest that fluorination leads to a stabilisation of the frontier molecular orbital levels and increased backbone planarity. The latter manifest itself as an enhanced propensity to aggregate and much higher melting point. Hole carrier mobilities in OFET devices are considerably enhanced in the backbone-fluorinated polymers, an observation attributed to the increased planarity of the polymer backbone. Computational calculations also predict an increased backbone rigidity and a strong preference for the coplanar arrangement of fluorinated thiophene rings. The origins of such planarisation are thought to be intramolecular in nature, likely from sulfur-fluorine inter-ring interactions as evidenced by S-F short contacts observed in the single crystal X-ray structure of a bithiophene monomer precursor. By synthesising well-defined diblock and alternating copolymers, backbone fluorination is then explored as a potential tool to control phase separation and dielectric constants, two key factors involved in the context of organic photovoltaic (OPV) devices. The utility of fluorine atoms as a good leaving-group in nucleophilic aromatic displacements on electron-poor aromatic systems is then used to produce a P3HT derivative end-capped with pentafluorobenzene. This polymer can then be reacted with good nucleophiles in mild conditions. As a proof of concept, three functional moieties are tethered to the P3HT derivative in this manner, opening the door towards sensing applications and hybrid organic/inorganic semiconductor interface engineering.
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Mendez, James D. "Conjugated Polymer Networks and Nanocomposites". Case Western Reserve University School of Graduate Studies / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=case1282841324.
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Zacca-Fadous, Maria-José. "Synthèse des matériaux hybrides organiques-inorganiques pour l’application dans l’énergie et l’environnement". Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS221/document.
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Le domaine des matériaux hybrides organiques-inorganiques prend beaucoup plus d'importance de jour en jour. Ce projet de thèse traite les avantages de ce genre de matériaux et synthétise des matériaux utilisés dans deux domaines, le premier celui de l'énergie et le second dans l'environnement.Des matériaux π-conjugués à base de poly(3-hexylthiophène) (P3HT) et de silice sont synthétisés et caractérisés. Il a été montré que l'auto-assemblage lors du procédé sol-gel favorise la polymérisation régiorégulière des motifs thiophènes au sein du matériau.D'un autre coté, des matériaux hybrides organisés (mésoporeux et lamellaires) fonctionnalisés par des groupements amines ou acides ont été préparés et caractérisés. Par des modifications chimiques simples, il a été possible de rendre ces matériaux utilisables comme résines échangeuses d’ions pour la dépollution de l'eau. Les résultats montrent que les matériaux lamellaires sodiques s'avèrent les plus efficaces. Ces mêmes matériaux sont testés au niveau de la catalyse chimique et de l'époxydation qui a ouvert plusieurs perspectives sur le sujetThe field of organic-inorganic hybrid materials takes much more importance day by day. This thesis project addresses the benefits of such materials and summarizes the materials used in two areas, energy and environment.Π-conjugated materials based on poly (3-hexylthiophene) (P3HT) and silica were synthesized and characterized. We showed that the organization obtained thanks to self-assembly of the alkylenes chains and during the sol-gel process promote a regioregular polymerization of thiophenes units.On the other hand, organized (mesoporous and lamellar) hybrid materials functionalized with amines or carboxylic acids groups were synthesized and characterized. By chemichal modifications zwitterionic materials were and used for ions extractions from water. The results show that the layered materials containig sodium ions are the most effective for the cations extraction. These same materials were tested as catalysts for epoxidation which opened several perspectives on the subject
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Zessin, Johanna [Verfasser], Michael [Gutachter] Mertig i Brigitte [Gutachter] Voit. "DNA Origami-Templated Synthesis of Semiconducting Polythiophene Filaments / Johanna Zessin ; Gutachter: Michael Mertig, Brigitte Voit". Dresden : Technische Universität Dresden, 2019. http://d-nb.info/1231847255/34.
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Kiriy, Nataliya. "Thiophene Based Semiconductors: Synthesis and Characterizations". Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2006. http://nbn-resolving.de/urn:nbn:de:swb:14-1141840200043-85237.
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Diverse conformational transitions and aggregations of regioregular head-to-tail polyhexylthiophene in different environments have been studied by means of AFM and UV-vis spectroscopy. A helical conformation of the main chain with 12 thiophenes rings per each helical turn has been proposed. Length of the particles varies from several nanometers to several hundreds nanometers and can be adjusted by the solvents composition or concentration of PATs. Such well-defined organic semiconductor 1D particles can be used as building blocks for future nanoscale and molecular level electronic devices. Oligothiophenes represent one of the most promising class of semiconductive materials for FET fabrication because of their good mobility and environmental stability. However, most of unsubstituted oligothiophenes are insoluble that suppresses their potential industrial utility. On the first stage of the work, conformation, crystalline structure, molecular packing and charge carrier mobility of the highly soluble regiochemically pure [Beta]-substituted sexithiophene were systematically studied. It was found that [Beta, Beta´]-DH6T possesses moderate PR-TRMC charge carrier mobility, but rather low field-effect mobility. The investigation showed that such a poor macroscopic electrical properties of [Beta, Beta´]-DH6T originate neither from the twist of the conjugated system nor from the crystalline disorder, but rather from low-dense crystalline packing and "wrong" molecular orientation. To overcome these obstacles two thiophene-based azomethines were designed to optimize a solubility, self-assembly, and a charge carrier mobility. The idea was to utilize the ability of the amide group to form strong hydrogen bonds in non-polar solvents and in solid state, but to be easily broken in presence of polar solvents. Thus, at the stage of a dissolution and a deposition, when the solubility is important, the hydrogen bonding can be "switched off" simply by addition of polar solvents and then, after the removal of polar additives, the self-assembly can be "switched on". It was found that incorporation of azomethine and amide moieties in the [Alpha, Omega]-position, and hexyl chains in [Beta]-position of quaterthiophene, indeed considerably improves the self-assembly properties without suppression of the solubility. Self-assembly of azomethine oligomers with (QT-amide) and without amide moieties (QT-aniline) were monitored by UV-vis, XRD, and AFM. It was found that QT-amide, processed from solution, forms highly ordered layered (terrace) structures. This aggregation mode is similar to the self-assembly of unsubstituted conjugated oligomers (such as pentacene) occurred upon their evaporation in vacuum. The sum of charge carrier mobilities (PR-TRMC data) for QT-aniline was shown to be below the detectable limit, but the mobility of QT-amide was determined to be 1.10-2 cm2 V-1 s-1. The later is comparable with the mobilities of the best organic semiconductors. All these significant differences in properties of related compounds can be attributed to the hydrogen bonding between QT-amide molecules responsible for the observed self-assembly.
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Nambiar, Rakesh R. "Designing new architectures for controlling solid state properties of conjugated polymers". Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/33935.
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Conjugated polymers and oligomers are great materials for use in the next generation devices namely organic field effect transistors, light emitting diodes and polymeric solar cells. Apart from having the potential for developing power-efficient, flexible, robust and inexpensive devices, conjugated polymers can also be tuned by molecular design to optimize device characteristics. One key problem for the full commercial exploitation of conjugated polymers is that the charge carrier mobility of the state-of-the-art polymer semiconductors is much lower than required for many applications. The performance of the devices is strongly dependent on the molecular structure and supermolecular assembly of the conjugated polymer chains. This thesis covers our attempts to design molecular structure to control and improve the solid state properties of conjugated polymers.
The relative placement of side chains along the backbone has a great influence on the solid state ordering of conjugated polymers. Poly(2,5-disubstituted-1,4-phenylene ethynylene)s (PPE)s, an important class of conjugated polymers, are generally synthesized by Pd-catalyzed coupling polymerizations of appropriately substituted diiodo and diethynyl benzenes (i.e., A-A and B-B type monomers). In asymmetrically substituted PPEs, this results in an irregular substitution pattern of the side chains along the polymer backbone. We report a new synthetic approach to prepare regioregular unsymmetrically substituted PPEs by polymerization of 4-iodophenylacetylenes (i.e., A-B type monomer). We provide a detailed discussion of various approaches to the synthesis of PPEs with different regioregularities and provide a description of the differences between regioregular and regiorandom analogs.
The effect of regioregularity becomes even more important when the two side chains are very dissimilar or amphiphilic. We explore the effect of relative placement hydrophobic (dodecyloxy) / hydrophilic (tri(ethylene glycol) and hydrophobic (dodecyloxy)/fluorophilic (fluoroalkyl) side chains along the poly(1,4-phenylene ethynylene) backbone. We found that the regioregular substitution of the polymer backbone provides a structure in which the side chains segregate to afford a Janus-type structure. The regioregular polymer chains pack more densely in a monolayer at the air-water interface, and pack into a bilayer in the solid state to form a highly crystalline material.
Pentacenes are very important organic molecules for use as semiconductor in oFETs due to their low band gap and high field effect mobility. One approach to reduce the bandgap of a polymeric system and improve performance is to include low bandgap small molecules into the conjugated backbone. A new copolymer system consisting of pentacene and terthiophene was developed and its optical and electronic properties along with its stability were evaluated.
We report the use of ultrasonication of P3HT as a novel operationally-simple process to significantly improve the field effect mobility of P3HT-based FETs, thereby potentially eliminating the need for dielectric surface modifications or further processing of the device. Investigation of the sonicated polymer samples by number of characterization techniques indicates that ultrasonication leads to aggregation and ordering of the P3HT chains resulting in increase in the mobility.
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Unur, Ece. "Synthesis Of Thiophene Capped Polytetrahydrofuran Conducting Copolymers". Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/4/1144625/index.pdf.
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Living polytetrahydrofuran (PTHF) was terminated with sodium thiophenemethonate to yield a polymer with thiophene groups at one (PTHF1) and both ends (PTHF2). Copolymerizations of PTHF1 and PTHF2 insulating polymers with pyrrole and thiophene were achieved in water-p-toluene sulfonic acid (PTSA) and acetonitrile (AN)-tetrabutylammonium tetrafluoroborate (TBAFB) solvent-electrolyte couples via constant potential electrolysis. Characterization of the samples were performed by Nuclear Magnetic Resonance Spectroscopy (NMR), cyclic voltammetry (CV), Fourier Transform Infrared Spectroscopy (FT-IR), Thermal Analyses (TGA), (DSC) and Scanning Electron Microscopy (SEM). Electrical conductivities were measured by four-probe technique. PTHF1/PTh and PTHF2/PTh films which were deposited on ITO-glass in dichloromethane-TBAFB solvent-electrolyte couple found out to be anodically coloring copolymers that electrochemically switch between an oxidized blue and reduced red state exhibiting electrochromic behavior. Spectroelectrochemical Analysis (SEC) was run in UV-VIS region to reach a better understanding of the band structures of PTHF1/PTh and PTHF2/PTh electrochromic copolymers. Optoelectrochemical analyses were introduced as a new method for the characterization of copolymers.
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Huang, Lung-Sheng, i 黃隆昇. "Synthesis of polythiophene with conductivity". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/qf42v5.
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碩士國立臺北科技大學
有機高分子研究所
98
Polythiophene is an important polymer, which can be used as OLED, feed effect transition, and solar-cells. In this experiment, poly(3,4-ethylenedioxythiophene) is synthesized. Their physical propertise are investigated by FTIR, UV, and NMR. The thermal stability is improved by silane treatment. The reason for increasing the thermal stability is the crosslinking reation occurred after the silan freatments. On the other hand, the PEDOT conductivity is studied by changing the solvent, doping material. The structure properties relationships is elucidated in this study.
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FANG, YI-CHIN, i 方怡欽. "The Optical Properties of Polythiophene Derivatives". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/46081947068728243848.
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碩士國立高雄應用科技大學
化學工程與材料工程系博碩士班
101
In this study, the Halogen dance reaction was adopted convert 2,5 phase 3-hexylthiophene into 2,4 phase 3-hexylthiophene, then using the Suzuki coupling reaction and Kumada coupling reaction to allow 2,4 phase 3-hexylthiophene copolymerize with several aromatics (fluorene and EDOT…etc) to obtain three type polymer (PF24)、(P3HT24HT)、(PEDOT24HT) whose absorbance and emission characteristics of the polymer solution and film were measured. Charactered by 1H-NMR spectroscopy, the Halogen dance reaction was successfully performed. From UV-visible absorption spectrometer (UV-vis), we learned that absorption peaks went on red shift when polymer solution was dried and became film, From UV-visible absorption spectrometer (UV-vis) and Photoluminescence spectrometer(PL) mix spectra, we learned that 2,4 phase 3-hexylthiophene series polymer had better stokes shift than 2,5 phase 3-hexylthiophene series polymer. Charactered by Mass spectroscopy, 2,4 phase 3-hexylthiophene series polymer had low molecular weight. Charactered by thermal gravimetric analyzer(TGA), 2,4 phase 3-hexylthiophene series polymer had not better thermal stability.
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Bondarev, Dmitrij. "Syntéza a charakterizace konjugovaných polymerů obsahujících fluorenové a thiofenové jednotky". Doctoral thesis, 2013. http://www.nusl.cz/ntk/nusl-322203.
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This Thesis is devoted to synthesis and characterization of conjugated polymers of three types: (i) copolymers of fluorene-based units with comonomers derived from benzene, anthracene and diphenyloxadiazole; (ii) copolymers combining new thiophene monomers carrying oxadiazole and triazole moieties with various comonomers. Copolymers are designed with the respect to the tuning the optical properties and an improvement in charge transport properties; (iii) polythiophene based polyelectrolytes of two types and the basic characterization of selected physical and optical properties is reported as well as a study of interactions with noble metal nanoparticles. An incorporation of oxadiazole side groups into the fluorene copolymers was followed by the substantial increase in the stability of emission (photoluminescence). Another increase in the emission stability was achieved by the substitution of alkyl side groups on fluorene for the aryl counterparts. Such a change resulted in almost complete suppression of the undesired green emission. Further method was the incorporation of anthracene monomeric units into the main chains which resulted in the best stabilization of emission. An experiment was also made in order to shed some light on the explanation of the mechanism of emission stabilization caused by...