Papers by Keyword: Conjugated Polymer

Abstract: Two novel copolymers consisting of 3-hexylthiophene and 4,4-di (thiophen-2-yl) biphenyl (DTBHT) or 4,4-di (thiophen-2-yl)-2-nitrobiphenyl (DTNHT) were synthesized. Both of the copolymers show lower HOMO energy level (-5.62, -5.51 eV) than that of the P3HT (-5.1 eV). Compared to DTBHT, adding nitro group in DTNHT improves effective conjugation of the main chain and successfully lowers the electrochemical bandgap of the copolymers from 2.39 to 2.28 eV and optical band-gap from 2.17 to 2.07 eV with significant increase in fluorescence quantum yield from 0.140 to 0.252. Keywords: biphenyl, 3-Hexylthiophene, conjugated polymer

Abstract: The synthesis and charaterization of a Zn-phtalocyanine is described. This compound is synthesized by microwaveassiseted methods. Here we report the synthesis of a phtalocyanine Zinc (ZnPc). The effect of the amount of catalyst and time on the polymerization yield of the polymers was studied. The structures were confirmed by UVvis and XPS sepctroscopies.

Abstract: Based on a tight binding model, we investigate impurity effect upon the stability of neutral and negatively or positively charged 1D conjugated polymer chains. Impurities are introduced by an attractive or a repulsive potential located at the lattice sites. The offsets of system energy due to light doping are calculated within adiabatic approximation. We show that doping position has significant impact upon system stability. A general picture of impurity distribution along the stretch direction of the polymer chain is obtained for both attractive and repulsive impurity potentials in neutral as well as in charged conjugated polymers. A polymer chain can generally be divided into edge, center and transition regions in terms of impurity distribution. It is found the static impurity distribution within a polymer is dominated by the strength and the sign of the impurity potential as well as whether the polymer chain is neutral or charged. Impurity distribution within the edge and the transition region is characterized by cluster and that within the center region by separation.

Abstract: A carbazole-based conjugated polymer bearing ruthenium complexes Pbpy(Ru)-Cz was synthesized aiming to obtain a material with dual functionalities of both light absorption and hole-transport for photovoltaic cells. Chemical structures of the monomers and polymers were confirmed by ¹H NMR, IR, and elemental analysis. Pbpy(Ru)-Cz showed good thermal stability and solubility. The absorption spectrum of Pbpy(Ru)-Cz showed a broader peak covering the wavelength range from 380 to 650 nm. Preliminary photovoltaic behavior was evaluated by fabricating photovoltaic cells. As measured under a 55 mW cm‾² compact white arc lamp, Voc, Jsc, FF and ηe of the device ITO/Pbpy(Ru)-Cz:PCBM/Al were 0.18 V, 0.019 mA cm‾², 0.22 and 1.40×10‾³%, pectively.

Abstract: Bulk heterojunction photovolataic devices based on blends of conjugated polymer poly (2- methoxyl-5- dodecoxyl p-phenyl vinylene) (PMODOPV) as electron donor and crystalline ZnO nanowires as electron acceptor have been studied. We show that photovoltaic devices using zinc oxide nanowires overlaid with conjugated polymers give improved performance compared with devices made only from polymer. The improvement is consistent with improved electron transport perpendicular to the plane of the film. Solar power conversion efficiency of 1.37% were achieved under AM1.5 illumination .

Abstract: Abstract. Polythiophene nanoparticles prepared by W/O microemulsion method were found to be photocatalytically active for degradation of Orange II dye and methyl Orange. During the photodegradation of Orange II and Methyl Orange as organic dyes in UV/H₂O₂ and UV irradiation systems using polythiophene nanoparticles as photocatalyst, it is exhibiting significant photocatalytic activity towards to double dyes in UV and UV/H₂O₂ system. the diameter of spherical polymer nanoparticles is 100±20 nm which was characterized by TEM with good dispersity. Furthermore, its photocatalytic efficiency for degradation of Orange II and Methyl Orange under UV irradiation is 2.54 and 1.95 times higher than normal polythiophene composites relatively. According to the testment by Accelerated Surface Area and Porosimetry System, The true cause lay in the fact that the specific surface area of Polythiophene nanoparticles is 106.6 m2/g compared to normal Polythiophene is 24.2 m2/g, This conjugated polymer characterized by FTIR spectroscopies before and after photocatalytic reactions shows reliable chemical stability. In addition, it held excellent recovery ability and kept up their catalytic activity with indistinctive drop after six repeated utilization.

Abstract: A new polypyrrole derivative 4-(1H-pyrrol-1-yl) phenyl 4-(1H-pyrrol-1-yl) butanoate (NPB) was synthesized by chemical method and characterized by 1H and 13C NMR spectroscopy. A new copolymer based on NPB and 3,4-ethylenedioxythiophene(EDOT) was electrochemically synthesized. Cyclic voltammogram and spectroelectrochemical characterization showed that the copolymer film had a well-defined reversible redox process as well as electrochromic behavior. Moreover, the copolymer film exhibited a multicolor electrochromism at different potentials, fast switching time of 0.8 s at 365 nm and an optical contrast of 17% at 1100nm.

Abstract: A copolymer based on 9-(4-pyrrol-1-yl-phenyl)-carbazole(PPC) and 3,4-ethylenedioxythiophene(EDOT) was electrochemically synthesized and characterized. The copolymer film not only presented a stable and well-defined redox process, but also exhibited three different colours(orange, green and greenish blue) under various applied potentials. Maximum optical contrast(△T%) and response time of the film were found to be 31% and 2 s at 1100 nm, respectively.

Abstract: A novel polyfluorene derivative, poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7- fluorene)-alt-2,7-(9,9- p-divinylbenzene)] (P-1) was synthesized by the palladium-catalyzed Suzuki coupling reaction and it’s quaternized ammonium polyelectrolyte derivatives was obtained through a postpolymerization treatment on the terminal amino groups. The electrochemical and optical properties of the resulting copolymers was fully investigated. The results showed that the new polyfluorene derivative had potential useful in used as materials for electronic conductivity, chemical and biological sensors that derive from its highly conductive and strong fluorescence.

Abstract: A Novel Polyfluorene Derivative, Poly[(9,9-Bis(3'-(N,N-Dimethylamino)propyl)-2,7- Fluorene)-Alt-2,7-(9,9- P-Divinylbenzene)] (P-1) Was Synthesized by the Palladium-Catalyzed Suzuki Coupling Reaction and it’s Quaternized Ammonium Polyelectrolyte Derivatives Was Obtained through a Postpolymerization Treatment on the Terminal Amino Groups. the Electrochemical and Optical Properties of the Resulting Copolymers Was Fully Investigated. the Results Showed that the New Polyfluorene Derivative Had Potential Useful in Used as Materials for Electronic Conductivity, Chemical and Biological Sensors that Derive from its Highly Conductive and Strong Fluorescence.