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    Electrochemical synthesis and characterization of polypyrrole/chitosan composite on platinum electrode: Its electrochemical and thermal behaviors
    (Elsevier Sci Ltd, 2010) Yalcinkaya, Sueleyman; Demetgul, Cahit; Timur, Mahir; Colak, Nureddin
    The electrochemical polymerization of conducting polymers is a simple and most convenient method for preparation of a film on the metal surface. The polypyrrole/chitosan composite film has been electrochemically synthesized on platinum electrode by using cyclic voltammetry (CV) technique. The synthesis solution was prepared by dissolving of pyrrole and chitosan in aqueous oxalic acid solution. The characterization of this film was done using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and thermal analysis (TG-DTA) techniques. The synthesized composite film was different in aspect of morphology when compared to chitosan and polypyrrole. The TG-DTA results revealed that the composite film had better thermal stability with respect to chitosan. The electrochemical measurement has shown that the composite film is very stable and electroactive. (C) 2009 Elsevier Ltd. All rights reserved.
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    Poly(o-anisidine) on brass
    (Korean Inst Chem Engineers, 2008) Ozyilmaz, Ali Tuncay; Ozyilmaz, Gul; Yilmaz, Ercan; Colak, Nureddin
    The electrochemical synthesis of poly(o-anisidine) (POA) was achieved on brass (CuZn) electrode by applying two scan rates (50 and 20 mVs(-1)). The synthesized polymer films were strongly adherent and homogeneous in both cases. Their corrosion performance was investigated by AC impedance spectroscopy (EIS) technique, anodic polarization plots and open circuit potential-time curves, in 3.5% NaCl solution. It was clearly seen that poly(o-anisidine) films provided a significant physical protection for longer exposure time. It was shown that polymer film coated at high scan rate (CuZn/POA-H) exhibited better barrier property against the attack of corrosive agents when compared with polymer film obtained at low scan rate (CuZn/POA-L). It was found out that poly(o-anisidine) film synthesized at high scan rate caused a significant increase in corrosion resistance by its catalytic behavior on formation of protective oxide layers on the surface in longer time.
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    Protective properties of polyaniline and poly(aniline-co-o-anisidine) films electro synthesized on brass
    (Elsevier Science Sa, 2007) Oezyilmaz, A. Tuncay; Colak, Nureddin; Ozyilmaz, Gul; Sanguen, A. Kemal
    Polyaniline and poly(aniline-co-o-anisidine) films were deposited on brass (Cu40Zn). The synthesis processes of homo and copolymer film were carried out under cyclic voltammetric condition from 0.12 M aniline and 0.06 M aniline +0.06 M o-anisidine containing 0.2 M sodium oxalate solutions. Homo and copolymer films were characterized by scanning electron microscopy (SEM). SEM images clearly show that one of the brass electrodes was covered with a black copolymer film of strongly adherent homogeneous characteristic while the other one with a porous dark green homo polymer one. The corrosion performances of coated and uncoated electrodes in 3.5% NaCl were evaluated with the help of AC impedance spectroscopy, anodic polarization plots and open circuit potential-time curves. The protective effect of homo and copolymer films formed on brass Grew in parallel with extended exposure time. It was only observed with copolymer-coated electrode that changes in the charge transfer resistance C of copolymer-coated electrode were related to strong adsorption of copolymer film on the brass surface which led to the formation of a protective oxide layer due to its catalytic behaviour. (c) 2007 Elsevier B.V. All rights reserved.
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    Solution dynamics of the dextran/crosslinking agent systems
    (Wiley, 2007) Ozdemir, Cemile; Colak, Nureddin; Guner, Ali
    The interaction of some selective Cl- and Ncontaining functional crosslinking agents such as epichlorohydrin (ECH), N,N'-methylenebisacrylamide (MBAM), and bifunctional agents such as glutaraldehyde (GA) and glycidylmethacrylate (GM) with dextran (Dx) in aqueous solutions were studied by viscometric and spectroscopic methods. The dynamic viscosities of Dx-crosslinker aqueous solutions have been measured at physiological temperature, 37 degrees C and in the concentration range of 0.220.4 g/dL. Concentration of crosslinkers were kept constant at 0.001-0.35 mol/L. Viscosity behavior of the solutions was interpreted using the Huggins and Kraemer equations. Moreover, the interaction between hydroxyl groups of the Dx with crosslinkers in aqueous solutions, structure properties was also confirmed thereby use of Raman and FTIR spectroscopy. For the Dx/crosslinker systems, the decreasing order of interaction was determined as ECH > GA > MBAM > GM. (c) 2007 Wiley Periodicals, Inc.
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    Synthesis and Characterization of Poly(Aniline-co-o-Aminoaniline)
    (Taylor & Francis Ltd, 2012) Yalcinkaya, Suleyman; Colak, Nureddin
    Poly(aniline-co-o-nitroaniline) co-polymer was synthesized by a chemical oxidation process using ammonium peroxydisulfate. The reaction was carried out in aqueous HCl solution with aniline and o-nitroaniline in a molar ratio of 4:1. Although o-nitroaniline did not homo-polymerize, the co-polymer of aniline with o-nitroaniline was readly synthesized. Poly(aniline-co-o-aminoaniline) was prepared by reducing poly(aniline-co-o-nitroaniline) in Fe catalyst at 90-100 degrees C. Co-polymer samples were characterized by FT-IR, UV-Vis and H-1-NMR spectroscopy, DSC and cyclic voltammetry. Also, solubility of the co-polymer samples was investigated with tetrahydrofuran (THF), dimethylsulfoxide (DMSO), dimethylformamide (DMF), N-methylpyrrolidone (NMP), chloroform, acetone and pyridine. DMF and DMSO were found as the best solvents for poly(aniline-co-o-aminoaniline) and poly(aniline-co-o-nitroaniline). In addition, poly(aniline-co-o-nitroaniline) was more soluble in DMF and DMSO than poly(aniline-co-o-aminoaniline). The DSC results and cyclic voltammetry studies showed that co-polymer samples had good thermal stability and electroactivity. (C) Koninklijke Brill NV, Leiden, 2012
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    Synthesis and characterization of poly(m-aminophenol)-succinat
    (Taylor & Francis Ltd, 2014) Dinc, Cemile Ozdemir; Yalcinkaya, Suleyman; Altuntas, Hazal; Colak, Nureddin
    Poly(m-aminophenol) (PMAP) and poly(m-aminophenol)-succinat compound (PMAP-Suc) containing ester bridge were synthesized in this study. PMAP were synthesized by chemical oxidative polymerization of m-aminophenol (MAP) in HCl medium with ammonium peroxydisulphate (APS) as an initiator at different temperatures. The optimum polymerization conditions (temperature: 25 degrees C, reaction time: 4 h, normalized MAP/APS ratio, k: 0.625 and mol of MAP/mol of APS, r: 0.5) of PMAP were determined. PMAP was esterified in N-methyl pyrrolidone by using solution of succinic acid as cross-linking agent and concentrated sulphuric acid as catalyst under appropriate ambient conditions. The general scheme of esterification and cross-linking reaction for PMAP is proposed. These reactions were also evidenced by spectroscopic, thermal and surface morphology as well as structural characteristics relationship of macromolecules. The structures of PMAP and PMAP-Suc were characterized by solubility test, FTIR, H-1 NMR and C-13 NMR, UV-vis spectroscopy, thermal (TGA-DTA) and SEM analyses.