Yazar "Sahin, Elif" seçeneğine göre listele

Listeleniyor 1 - 3 / 3
  • Küçük Resim Yok
    Öğe
    ENVIRONMENTALLY FRIENDLY ENZYME-CATALYZED POLYMERIZATION OF A NOVEL PHENOXY-KETIMINE
    (Gh Asachi Technical Univ Iasi, 2017) Tapan, Senem; Sahmetlioglu, Ertugrul; Demir, Haci Okkes; Turac, Ersen; Sahin, Elif
    The monomer with ketimine side group, 2-(1-(benzylimino) ethyl) phenol (2-BEP), was synthesized from the condensation of 2-hydroxyacetophenone and benzyl amine. The enzymatic oxidative polymerization of 2-BEP was performed in the presence of hydrogen peroxide using horseradish peroxidase (HRP) as catalyst. The oxidation reaction was carried out in various solvents and phosphate buffers at room temperature. These studies have shown that a dark brown polymer was successfully synthesized by utilizing aqueous methanol as the cosolvent at pH 7.0. Poly(2-BEP) shows good solubility in DMF and DMSO, but it is insoluble in THF, methanol, water, acetone and chloroform. Characterization of poly(2-BEP) was carried out via UV-vis, FT-IR, H-1-NMR, C-13-NMR and GPC techniques. The number-average molecular weight (M-n), weight-average molecular weight (M-w) and polydispersity index (PDI) of the polymer were determined to be 1157.4 g mol(-1), 2039.6 g mol(-1) and 1.76, respectively. FTIR and H-1-NMR studies confirmed the presence of phenylene and oxyphenylene units within the polymer backbone. The optical band gaps (E-g) of 2-BEP and poly(2-BEP) were calculated as 4.10 eV and 3.86 eV, respectively.
  • Küçük Resim Yok
    Öğe
    Fine tuning of color via copolymerization and its electrochromic device application
    (ELSEVIER SCIENCE SA, 2008) Camurlu, Pinar; Sahmetlioglu, Ertugrul; Sahin, Elif; Akhmedov, Idris Mecidoglu; Tanyeli, Cihangir; Toppare, Levent
    In this study electrochemical copolymerization of 1-(perfluorophenyl)-2,5-di(thiophen-2-yl)-1H-pyrrole and 3,4-ethylenedioxythiophene was used to fulfill a strategy in achieving desired multichromic properties. The resultant polymer displayed distinct color changes between red-violet, amber, green and blue color with good switching times and optical contrast. A direct correlation between the color of the polymer in neutral state and the applied potential during synthesis was observed. Hence, it was possible to achieve colors from maroon, red-violet, and eggplant to indigo depending on the applied potential. A dual type electrochromic device of the copolymer and poly(3,4-ethylenedioxythiophene) was constructed to evaluate the possible use of such copolymer in device applications. The device displayed multichromism, with 1.1 s switching time and good electrochromic memory. (C) 2007 Elsevier B.V. All rights reserved.
  • Küçük Resim Yok
    Öğe
    Synthesis and characterization of a new soluble conducting polymer and its electrochromic devices
    (ELSEVIER SCIENCE BV, 2006) Sahin, Elif; Sahmetlioglu, Ertugrul; Akhmedov, Idris M.; Tanyeli, Cihangir; Toppare, Levent
    A new polythiophene derivative was synthesized by both chemical and electrochemical oxidative polymerization of 1-(perfluorophenyl)-2,5-di(2-thienyl)-1H-pyrrole (FPTPy). The structures of both the monomer and the soluble polymer were elucidated by nuclear magnetic resonance (H-1-NMR) and fourier transform infrared (FTIR). Polymer of FPTPy was also synthesized via potentiostatic electrochemical polymerization in acetonitrile (AN)/NaClO4/LiClO4 (0.1 M:0.1 M) Solvent-electrolyte couple. Characterizations of the resulting insoluble polymer were performed by cyclic voltammetry (CV), FTIR, scanning electron microscopy (SEM) and UV-Vis Spectroscopy. Four-probe technique was used to measure the conductivities of the samples. Moreover, the spectroelectrochemical and electrochromic properties of the polymer film were investigated. In addition, dual type polymer electrochromic devices (ECDs) based on P(FPTPy) with poly(3,4-ethylenedioxythiophene) (PEDOT) were constructed. Spectroelectrochemistry, electrochromic switching and open circuit stability of the devices were studied. They were found to have good switching times, reasonable contrasts and optical memories. (C) 2006 Elsevier B.V. All rights reserved.