Conjugated Polymer
Mostrando 25-36 de 50 artigos, teses e dissertações.
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25. Processos radiativos e não radiativos em polímeros conjugados emissores de luz. / Radiactive and non-radiactive processes in light-emitting conjugated polymers.
O presente trabalho tem como objetivo estudar os processos radiativos e não radiativos em filmes automontados de poli(p-fenileno vinileno), ou PPV, sintetizados e processados no Grupo de Polímeros Prof. Bernhard Gross (GPBG) do IFSC. Além de adquirir conhecimento das propriedades ópticas fundamentais, tais como, os mecanismos básicos responsáveis pela
Publicado em: 2001
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26. Propriedades Ópticas de Semicondutores Orgânicos à Base de Polímeros Emissores de Luz / Optical proprieties of organic semiconductors based on light emitting polymers.
In this work, we studied the optical proprieties of absorption and emission of luminescent conjugated polymers based on poly(p-phenylene vinylene) (PPV). This material was processed in thin films by casting, spin-coating, self-assembled (SA) e Langmuir-Blodgett (LB) techniques, available in the Grupo de Polímeros Bernhard Gross, where the samples were chara
Publicado em: 2001
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27. Estudo da estabilidade conformacional do copolimero poliazina-policarbonitrila
The trans-polycarbonitrile polymer presents a strong deviation from the planarity suggesting that this conformation does not correspond to the most stable structure of the system. These non-planarity can affect significantly the electronic properties of the polymer. On the other hand the polyazine derivative, a conjugated polymer, a nitrogen containing analo
Publicado em: 1999
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28. DESENVOLVIMENTO E CARACTERIZAÇÃO DE DISPOSITIVOS FOTÔNICOS UTILIZANDO POLÍMEROS / DEVELOPMENT AND CHARACTERIZATION OF PHOTONIC DEVICES
Conjugated organic polymers are of wide interest as nonlinear optical materials because of their potential applications in photonic devices, such as communication devices. They have a large and fast nonlinear optical response, as well as a great flexibility in their preparing method. For device applications, the most important parameters are: third-order opt
Publicado em: 1996
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29. Polimeros como matrizes para reações fotoquimicas de compostos organometalicos
In this thesis a new technique using polymers particularly polytetrafluorethylene (PTFE) and low-density polyethylene (LDPE) was devclaped, to study at ambient conditions by means of infrared spectrophotametry, the following photochemical reactions: - the substitution af the carbonyls of Fe(CO)5 by conjugated dienes and mono-olefins. - the photofragmentation
Publicado em: 1983
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30. Twisting macromolecular chains: Self-assembly of a chiral supermolecule from nonchiral polythiophene polyanions and random-coil synthetic peptides
The self-assembly of a negatively charged conjugated polythiophene derivative and a positively charged synthetic peptide will create a chiral, well ordered supermolecule. This supermolecule has the three-dimensional ordered structure of a biomolecule and the electronic properties of a conjugated polymer. The molecular complex being formed clearly affects the
National Academy of Sciences.
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31. Fluorescent-conjugated polymer superquenching facilitates highly sensitive detection of proteases
Sensor formats have been developed for detecting the activity of proteolytic enzymes based on fluorescent conjugated polymer superquenching. These sensors employ a reactive peptide sequence within a tether linking a quencher to a biotin. The peptide binds to sensors containing colocated biotin-binding protein and fluorescent polymer by means of biotin–biot
National Academy of Sciences.
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32. Beyond superquenching: Hyper-efficient energy transfer from conjugated polymers to gold nanoparticles
Gold nanoparticles quench the fluorescence of cationic polyfluorene with Stern–Volmer constants (KSV) approaching 1011 M—1, several orders of magnitude larger than any previously reported conjugated polymer–quencher pair and 9–10 orders of magnitude larger than small molecule dye–quencher pairs. The dependence of KSV on ionic strength, charge
National Academy of Sciences.
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33. DNA detection using water-soluble conjugated polymers and peptide nucleic acid probes
The light-harvesting properties of cationic conjugated polymers are used to sensitize the emission of a dye on a specific peptide nucleic acid (PNA) sequence for the purpose of homogeneous, “real-time” DNA detection. Signal transduction is controlled by hybridization of the neutral PNA probe and the negative DNA target. Electrostatic interactions bring t
National Academy of Sciences.
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34. Highly sensitive biological and chemical sensors based on reversible fluorescence quenching in a conjugated polymer
The fluorescence of a polyanionic conjugated polymer can be quenched by extremely low concentrations of cationic electron acceptors in aqueous solutions. We report a greater than million-fold amplification of the sensitivity to fluorescence quenching compared with corresponding “molecular excited states.” Using a combination of steady-state and ultrafast
The National Academy of Sciences.
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35. Single chain spectroscopy of conformational dependence of conjugated polymer photophysics
Single molecule confocal fluorescence microscopy was used to perform photoluminescence spectroscopy on single, isolated molecules of the conjugated polymer poly[2-methoxy,5-(2′-ethyl-hexyloxy)-p-phenylene-vinylene] (MEH-PPV). We show that the fluorescence from single chains of this electroluminescent polymer depends strongly on chain conformation. The
The National Academy of Sciences.
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36. Methods for strand-specific DNA detection with cationic conjugated polymers suitable for incorporation into DNA chips and microarrays
A strand-specific DNA sensory method is described based on surface-bound peptide nucleic acids and water-soluble cationic conjugated polymers. The main transduction mechanism operates by taking advantage of the net increase in negative charge at the peptide nucleic acid surface that occurs upon single-stranded DNA hybridization. Electrostatic forces cause th
National Academy of Sciences.