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Öğe Chemical synthesis and characterization of poly (pyrrole-co-o-aminophenol)/chitosan composite(Springer, 2022) Yalcinkaya, Suleyman; Duran, SirinIn this study, poly(pyrrole-co-o-aminophenol)/chitosan composite samples were synthesized by chemical method (as powder) in solutions of different molar ratios of pyrrole and o-aminophenol (8:2, 1:1 and 2:8). Composite samples were characterized by FT-IR (Fourier Transform Infrared), solubility tests, H-1-NMR (Nuclear Magnetic Resonance), DSC (Differential Scanning Calorimetry), CV (Cyclic Voltammetry) and SEM (Scanning Electron Microscope) images. As a results of the solubility test, it was observed that the solubility of the composite decreased as the pyrrole ratio increased. Also, the best solvents for composite samples determined as DMSO and DMF. When SEM images of copolymer and composite samples are examined, it is seen that the copolymer structure shows a structure in the form of regular small particles, while large nebula-shaped structures are formed after composite formation with chitosan. In addition, it was determined that the structures of the composite samples prepared in solutions containing different ratios of monomers differ from each other depending on the monomer ratios. According to DSC thermal analysis results of composite samples, it was concluded that the thermal stability of the composite samples having high pyrrole ratio (8:2) was better than the composite samples having low pyrrole ratio (1:1, 2:8). The electrochemical behavior of the composites was achieved by cyclic voltammetry technique. Electrochemical stability studies show that composite samples have good redox behavior, do not degrade during redox behavior, and are therefore very stable electrochemically.Öğe Electrochemical synthesis and characterization of poly (o-amino benzyl alcohol) and poly (o-amino benzyl alcohol-co-o-anisidine)(Wiley, 2021) Yalcinkaya, Suleyman; Cakmak, Didem; Seymen, Kubra; Demetgul, CahitIn this study; poly (o-amino benzyl alcohol) and poly (o-amino benzyl alcohol-co-o-anisidine) copolymer films were electrochemically synthesized by cyclic voltammetry technique on the platinum electrode. The synthesis of copolymer films was achieved in various monomers feed ratio (o-amino benzyl alcohol: o-anisidine; 8:2, 1:1, 2:8) of o-amino benzyl alcohol and o-anisidine. Different solution types were tested in aqueous and non-aqueous media, especially during the synthesis process, as the electrolyte medium. As a result of the experiments, it was determined that sulfuric acid solution was the most suitable solution for both homopolymer and copolymer film growth. Homopolymer and copolymer samples were characterized by FT-IR, cyclic voltammetry (CV), SEM, digital images and TGA/DTA techniques. The CV, SEM and digital images results indicated that the solution which has high ratio of monomer is more effective in copolymer film synthesis mechanism. TGA results showed that the 1:1 copolymer film had higher thermal stability than the films at other monomer ratios. Also, electrochemical studies exhibited that the copolymer film in 1:1 ratio is partially more electrochemically stable than other copolymer films.Öğe Electrochemical synthesis of poly(o-anisidine)/chitosan composite on platinum and mild steel electrodes(Elsevier Science Sa, 2013) Yalcinkaya, SuleymanIn this study, poly(o-anisidine)/chitosan composite film was electrochemically synthesized on the platinum and mild steel electrodes. Electrochemical synthesis of the composite film was carried out by cyclic voltammetry technique. The synthesized composite film was characterized by FT-IR, UV-Vis, cyclic voltammetry, SEM and TGA. The SEM micrographs showed that the composite film homogeneously covered the surfaces of platinum and mild steel electrodes. The TGA results proved that the composite film does not degrade until 648 degrees C while the poly(o-anisidine) film is decomposed between 190 and 432 degrees C. Also, electrochemical studies showed that poly(o-anisidine) and the composite films have good stability and electroactivity. (C) 2012 Elsevier B.V. All rights reserved.Öğe Electrochemical synthesis of poly(pyrrole-co-o-anisidine)/chitosan composite films(Elsevier Science Bv, 2017) Yalcinkaya, Suleyman; Cakmak, DidemIn this study, poly(pyrrole-co-o-anisidine)/chitosan composite films were electrochemically synthesized in various monomers feed ratio (pyrrole: o-anisidine; 9:1, 7:3,1:1, 3:7 and 1:9) of pyrrole and o-anisidine on the platinum electrode. Electrochemical synthesis of the composite films was carried out via cyclic voltammetry technique. They were characterized by FT-IR, cyclic voltammetry, SEM micrographs, digital images, TGA and DSC techniques. The SEM results indicated that the particle size of the composite decreased with increasing o-anisidine ratio and the films became more likely to be smooth morphology. The TGA results proved that the film of the composite with 1:1 ratio showed highest final degradation temperature and lowest weight loss (83%) compared to copolymer and 9:1 1:9 composite films. The 1:1 composite film had higher thermal stability than copolymer and the other composite films (9:1 1:9). Meanwhile, electrochemical studies exhibited that the 1/9 composite film had good electrochemical stability as well. (C) 2017 Elsevier B.V. All rights reserved.Öğe Electropolymerization of CuII-(N,N?-bis(3-methoxysalicylidene)-2-aminobenzylamine) on platinum electrode: Application to the electrocatalytic reduction of hydrogen peroxide(Elsevier Science Sa, 2011) Deletioglu, Didem; Yalcinkaya, Suleyman; Demetgul, Cahit; Timur, Mahir; Serin, SelahattinThe complex of copper (II) with N,N'-bis(3-methoxysalicylidene)-2-aminobenzylamine (H2L) was synthesized and characterized by elemental analysis, magnetic susceptibility, UV-vis. and FT-IR spectroscopy. The results showed that the tetradentate ligand coordinated to the Cu(II) ion through the azomethine nitrogen and phenolic oxygen atoms. The prepared complex [CuL] was electropolymerized on platinum electrode surface in a 0.1 mol dm(-3) solution of lithium perchlorate in acetonitrile by cyclic voltammetry between 0 and 1.6V vs. Ag/Ag+. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), conductance measurements, FT-IR and SEM were used to characterize polymer film of Cu(II) complex. The reduction of hydrogen peroxide on poly[CuL] has been investigated mainly in phosphate buffer medium (pH 7.2), between 0 and -0.8 V versus Ag/Ag+ at a scan rate 0.1 V s(-1). (c) 2011 Elsevier B.V. All rights reserved.Öğe Immobilization of Co II-(N,N?-bis(salicylidene)-2-aminobenzylamine) on Poly(pyrrole-co-o-anisidine)/Chitosan Composite Films: Application to Electrocatalytic Oxidation of Catechol(Wiley-V C H Verlag Gmbh, 2021) Yalcinkaya, Suleyman; Cakmak, DidemIn this study, poly (pyrrole-co-o-anisidine)/chitosan composite (Cs) films were prepared by cyclic voltammetry technique on platinum electrode using different pyrrole and o-anisidine mole ratios. Immobilization process was accomplished in Co-II-(N,N '-bis(salicylidene)-2-aminobenzylamine)(CoL) dissolved 0.15 M acetonitrile-LiClO4 solution by cyclic voltammetry technique at 0.2-2.0 V potential range. Three electrode methods were applied in all electrochemical studies. After immobilization process, the characterizations of the electro catalytic surfaces (Cs-CoL-Pt) were carried out by cyclic voltammetry and SEM images. The SEM images clearly indicated that the [CoL] complex is immobilized onto composite films. The electrocatalytic activity of the modified electrodes on the catechol was investigated using buffer solutions of different pH values. The results of catalytic studies revealed that, pH=10 buffer solution was the optimal solution and 1 : 1 Cs-CoL-Pt electrode was the best electrode for catechol oxidation. In square wave voltammetry measurements using this electrode, two linear working ranges were determined. The linear response ranges for catechol determination were found as 3.0 mu M-6.0 mu M and 16 mu M-80 mu M for the first and the second linear working ranges, respectively, with 1.1 mu M detection limit.Öğe Preparation and characterization of polypyrrole/dextran sulphate composite: its electrochemical and thermal behaviors(Springer, 2015) Yalcinkaya, Suleyman; Demirbilek, Celile; Dinc, Cemile OzdemirPolypyrrole/dextran sulphate (PPy/Dx-SO4) composite was synthesized in 1 M HCl medium by chemical polymerization method. The synthesized composite was characterized using H-1-NMR, UV-Vis, FT-IR, SEM micrographs, cyclic voltammetry, TG-DTA and viscosity measurements. The SEM micrographs were clearly indicated that PPy, Dx-SO4 and PPy/Dx-SO4 composite have different morphology. The composite architecture is also seen alike as globular and agglomerate particles. The composite has better thermal stability than Dx-SO4. The results of the solubility studies indicated that the composite partially dissolved in DMSO, DMF, and NMP. Additionally, the composite was more soluble in these solvents than PPy, providing technological usefulness. The electrochemical studies showed that PPy/Dx-SO4 composite has low electrical conductivity, but it has good electrochemical stability than PPy.Öğe Synthesis and Characterization of Poly(Aniline-co-o-Aminoaniline)(Taylor & Francis Ltd, 2012) Yalcinkaya, Suleyman; Colak, NureddinPoly(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, 2012Öğe Synthesis and characterization of poly(m-aminophenol)-succinat(Taylor & Francis Ltd, 2014) Dinc, Cemile Ozdemir; Yalcinkaya, Suleyman; Altuntas, Hazal; Colak, NureddinPoly(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.Öğe Synthesis of salen-type Schiff base metal complexes, electropolymerization on graphite electrode surface and investigation of electrocatalytic effects(Elsevier Science Sa, 2018) Cakmak, Didem; Cakran, Sinem; Yalcinkaya, Suleyman; Demetgul, Cahit2-Aminobenzylamine-based unsymmetrical salen-type Schiff base and its Cu (II), Ni (II), Co (II) and Fe (III) metal complexes were synthesized and their structures were investigated by various spectroscopic methods. The electropolymerization of the synthesized metal complexes were achieved on the graphite electrode. The electropolymerization process was conducted by cyclic voltammetry (CV) in a 0.15 M LiClO4/Acetonitrile as supporting electrolyte medium. Characterization of the polymer coated electrodes were carried out by CV, SEM, EDX and UV-Vis techniques. The electrocatalytic activities of graphite electrodes modified with Schiff-base metal complex were investigated in the determination of compounds such as Dopamine (DA), Catechol (CC), Cysteine (Cys) and Uric Acid (UA). These studies showed that the salen-type Schiff base-Ni(II)-modified graphite electrode gave the best result in the determination of catechol and dopamine. Square wave voltammetry showed a linear response in the range of 0.09-0.35 mu M and 0.22-0.58 mu M with LoD of 0.03 mu M and 0.06 mu M for CC and DA, respectively.
