Conjugated Polymers
Mostrando 13-24 de 51 artigos, teses e dissertações.
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13. Síntese e caracterização de derivados do politiofeno para utilização em sensores / Synthesis and characterization of polythiophene derivatives and their use in VOCs sensor applications
The conjugated polymers, especially polythiophenes, have emerged as alternative materials to obtain chemically selective layers in gas sensors. The main advantages of these materials are the possibility of obtaining sensing devices that operate at room temperature and the diversity of materials. For example, a simple modification of the side chain of polythi
Publicado em: 2010
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14. Photochemistry of conjugated polymers containing charge transfer sites and energy migration / Fotoquímica de polímeros conjugados contendo centros de transferência de carga e migração de energia
Neste trabalho foram estudados os processos de migração e transferência de energia em derivados de polifluoreno, de estrutura totalmente conjugada e de conjugação confinada. A dinâmica de estado excitado dos derivados PF-BNI, PFOPPV e PFPPV foi estudada em solução diluída de diferentes solventes através de espectroscopia eletrônica de alta resolu�
Publicado em: 2010
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15. Estudo de materiais, estruturas de dispositivos e fenômenos de transporte em sistemas fotovoltaicos híbridos orgânico-inorgânico / Study of materials, device structures and transport phenomena in hybrid photovoltaic systems
Recently a fast development in organic and hybrid photovoltaic field has been observed. Such devices are fabricated by organic semiconductors within components of a heterojunction, in which bulk heterojunctions obtained via interpenetrating networks at the sub-20-nm length scale. It permits the effective collection of photogenerated charge carriers even with
Publicado em: 2010
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16. Influência da radiação gama em filmes de PPV e PTHT: caracterização óptica e elétrica
In this work, we investigated the effects of Gamma ionizing radiation on optical properties of the polyeletrolite poly (chloride Tetrahydrothiophen of xililideno) (PTHT) and the conjugated polymer poly(p- phenylene vinileno) (PPV). The PPV films were processed from PTHT films and it was submitted on the annealing step at low (110oC) and higher (200oC) under
Publicado em: 2009
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17. Síntese, caracterização e aplicação de polímeros conjugados derivados de ferroceno e de bisfenol-A / Synthesis, characterization and application of conjugated polymers derived from ferrocene and bisphenol-A
Owing to the current interest in organometallic polymers and their applications, a group of conducting polymers containing ferrocene in the main chain was synthesized aiming the study of their magnetoresistive, magneto-optic and redox properties. The following polymers were prepared via McMurry method: poly(1,1-ferrocenylenevinylene) (PFV) and poly[1,1-ferro
Publicado em: 2008
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18. Efeito da fotocondução em diodos com camada ativa de derivados de poli(p-fenileno vinileno) (PPV) / Photoconduction effect in single layer diodes based on PPV derivatives.
This thesis is a study about photoconductivity in polymeric materials, in particular diodes with single-layer sandwich structure derivates of poly(para-phenylene vinylene) (PPV): OC10-PPV, SY and MEH-PPV. Different metallic electrodes were deposited on the same polymeric layer. Therefore, it was necessary to realize the devices fabrication process step by st
Publicado em: 2008
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19. Estudo atomístico da formação de interfaces orgânico-inorgânico: Tiofenos sobre óxido de titânio / Atomistic study of the formation of organic-inogarnic interfaces: thiophenes over titanium oxide
No estudo de sistemas híbridos orgânico-inorgânico, o uso de materiais como polímeros conjugados e óxidos de metal de transição tem despertado grande interes- se. Em particular, destacam-se sistemas compostos de tiofenos e óxido de titânio, que encontram uma importante aplicação em células solares. Para um melhor entendimento da interação entre
Publicado em: 2008
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20. Photoluminescence excited in the ultraviolet in conjugated polymers / "Fotoluminescência excitada no ultravioleta em polímeros conjugados"
Os polímeros conjugados luminescentes são materiais com grande potencial tecnológico, mas apesar de estudados desde a década de 80, algumas de suas propriedades óticas ainda não foram totalmente entendidas. Por exemplo, ainda persistem dúvidas quanto à natureza das suas excitações primárias. Nesse sentido foi feito um estudo da fotoluminescência
Publicado em: 2007
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21. Dispositivos poliméricos eletroluminescentes
Here we present an overview of electroluminescent devices that use conjugated polymers as the active media. The principal components of the devices are described and we show some examples of conjugated polymers and copolymers usually employed in polymeric light emitting devices (PLED). Some aspects of the photo and electroluminescence properties as well as o
Química Nova. Publicado em: 2006-04
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22. Correlation between luminescence polarization and molecular orientation in conjugated polymers / Correlação entre polarização da luminescência e orientação molecular em polímeros conjugados
The main goal of this work is the understanding of intermediated energy relaxation processes that are governed by Energy Transfer. Such processes strongly affect the optical properties of conjugated polymers, reducing the emission efficiency and the life time of OLEDs. We study specifically the polymer poly(p-phenylene vinylene), PPV, synthesized through the
Publicado em: 2006
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23. Polaron dynamics with impurities in conjugated polymers
We study the charge transport by polarons in conjugated polymers in the presence of impurities. The effects on the polaron motion due to the symmetry of the chain is considered. The polaron dynamics in doped conjugated polymers is numerically studied using the Su-Schrieffer-Heeger (SSH) model combined with the Pariser-Parr-Pople (PPP) model modified to inclu
Brazilian Journal of Physics. Publicado em: 2005-12
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24. Synthesis and determination of the electron affinity, ionization potential and energy of band prohibited of electroluminescent polymers / Síntese e determinação da afinidade eletrônica, potencial de ionização e energia de banda proibida de polímeros eletroluminescentes
In this work we describe the electrochemical and optical aspects of a series of electrochemically synthesized blue-electroluminescent conjugated polymers. The materials employed here comprised poly(p-phenylene) (PPP), poly(pyrro1e) (PPI), poly(3-methylthiophene) (P3MET), poly(p-pheny1ene-pyrrole) (CPPI) copolymer and poly(p-phenylene3methyIthiophene) (CP3MET
Publicado em: 2004