Browsing by Subject "Conjugated Polymers"

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    Synthesis and characterization of water dispersible conjugated polymer nanoparticles
    (2011) İbrahimova, Vusala
    In this study, novel water dispersible conjugated polymer nanoparticles having various potential applications in the areas including biomedicine and photonics have been synthesized from blue, green and yellow light emitting conjugated polymers. Their sizes, morphology, surface charges and optical properties have been determined using various techniques. Cell viability of nanoparticles was tested in mesenchymal stem cells. For the synthesis of nanoparticles, first the following polymers carrying a number of different functional groups and based on derivatives of fluorene and benzothiodiazole monomers are designed and synthesized using the Suzuki coupling reactions: Poly[(9,9-bis{propeny}fluorenyl-2,7-diyl)-co-(9,9-dihexyl-9H-fluorene)] (P1), poly[(9,9-bis{carboxymethylsulfonyl-propyl}fluorenyl-2,7-diyl)-co-(9,9-dihexyl-9Hfluorene) (P2), poly[(9,9- bis{propeny}fluorenyl-2,7-diyl))-co-(1,4-benzo-{2,1,3}- thiodiazole)] (P3), poly[(9,9- bis{carboxymethylsulfonyl-propyl}fluorenyl-2,7-diyl)- co(1,4-benzo-{2,1,3}-thiodiazole)] (P4), poly[(9,9-bis{3-bromopropyl}fluorenyl- 2,7-diyl)-co-(1,4-benzo-{2,1,3}-thiodiazole)] (P5), poly[(9,9-bis{3- azidopropyl}fluorenyl-2,7-diyl)-co-(benzothiadiazole)] (P6). Polymers were characterized by using spectroscopic techniques such as 1H-NMR, FT-IR, UV-Vis, Fluorescence spectrophotometer and Gel Permeation Chromatography (GPC). Conjugated polymers carry functional groups on their side chains, such as azide and allyl groups that can be cross-linkable using UV light to form shape-persistent, stable nanoparticles. Nanoparticles were characterized by various techniques before and after UV-treatment. Their sizes and morphologies were determined by using dynamic light scattering measurements (DLS) and imaging techniques such as scanning electron microscopy (SEM) and atomic force microscopy (AFM). For optical characterization UV-vis, fluorescent spectroscopies and FT-IR were used. CNPs affect on cells shows their nontoxic and biocompatible properties which give opportunity to use them in cell imaging.
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    ItemOpen Access
    White emitting polyfluorene functionalized with azide hybridized on near-UV light emitting diode for high color rendering index
    (Optical Society of America, 2008) Huyal, I. O.; Ozel, T.; Koldemir, U.; Nizamoglu, S.; Tuncel, D.; Demir, Hilmi Volkan
    We develop and demonstrate high-quality white light generation that relies on the use of a single-type simple conjugated polymer of polyfluorene functionalized with azide groups (PFA) integrated on a near-UV LED platform. The high-quality white emission from the polyfluorene is achieved by using the azide functionalization to facilitate cross-linking intentionally when cast into solid-state form. Hybridized on n-UV InGaN/GaN LED at 378 nm, the PFA emitters collectively generate a very broad down-converting photoluminescence at longer wavelengths across the entirety of the visible spectrum, yielding high color rendering indices up to 91. (c) 2008 Optical Society of America.