Synthesis, characterization, thermal stability and electrochemical properties of ortho-imine-functionalized oligophenol via enzymatic oxidative polycondensation

WOS: 000439781600002Ortho-imine functionalized oligophenol was synthesized via enzymatic polymerization of 2-((4-nitrophenylimino) methyl) phenol (NPIMP). Enzymatic polymerization was catalyzed by Horseradish peroxidase (HRP) enzyme and hydrogen peroxide (H2O2) oxidizer yielded oligophenol with imine functionality on the side-chain. Effects of various factors including reaction pH, temperature and solvent system on the polymerization were studied. Optimum polymerization with the highest yield (96 %) and number-average molecular weight (M-n = 7300 g/mol, degree of polymerization approximate to 30) was accomplished using equivolume mixture of acetone/pH 7.0 phosphate buffer medium at 35 degrees C in 24 h under air. Characterization of the resulting oligomer was accomplished by ultraviolet-visible spectroscopy (UV-Vis), fourier transform infrared spectroscopy (FT-IR), H-1 and C-13 nuclear magnetic resonance (H-1 and C-13 NMR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), cyclic voltammetry (CV) and gel permeation chromatography (GPC). The polymerization involved elimination of hydrogen from NPIMP, and the oligomer possessed phenolic -OH end groups. The oligomer backbone was composed of oxyphenylene and phenylene repeat units. The optical band gaps (Eg) of NPIMP and oligo(NPIMP) were measured as 3.21 and 3.39 Eg, respectively. Thermal stability of the oligo(NPIMP) was also found to be relatively high, and lost 5 % of its mass at 175 degrees C and lost 50 % of its mass at 600 degrees C.Scientific and Technological Research Council of Turkey (TUBITAK) [115Z482]This research was partially supported by the Scientific and Technological Research Council of Turkey (TUBITAK) (115Z482)

Synthesis, characterization and optoelectrochemical properties of poly(1,6-bis(2,5-di(thiophen-2-yl)-1H-pyrrol-1-yl)hexane) and its copolymer with EDOT

WOS: 000259690500009A new polythiophene derivative was synthesized by electrochemical oxidative polymerization of 1,6-bis(2,5-di(thiophen-2-yl)-1H-pyrrol-1-yl)hexane (TPH). The structure of the monomer was elucidated by H-1, C-13, MR and mass analyses. The polymer P(TPH) and its copolymer with 3,4-ethylenedioxythiophene (P(TPH-co-EDOT)) were synthesized via potentiostatic electrochemical polymerization. Characterizations of the resulting polymers were performed by cyclic voltammetry (CV), FTIR, UV-vis spectroscopies; and conductivity measurements. Moreover, the spectroelectrochemical and electrochromic properties of the polymer films were investigated. While P(TPH) has only three colors in oxidized and neutral states (blue, green and yellow), its copolymer with EDOT has five different colors (purple, red, light gray, green, and blue). Optical contrast and switching time of the polymer film were improved via copolymerization. It was found that with increasing applied potential the amount of PEDOT in the copolymer composition increases and band gap (E-g) of the copolymer decreases. (C) 2008 Elsevier B.V. All rights reserved.TUBA; DOSAP program METU; [DPT-2005K120580]The authors gratefully thank TUBA, DPT-2005K120580 grants and DOSAP program METU

Sustainable polysiloxanes via siloxane metathesis

WOS: 000432475704163

Horseradish peroxidase-catalyzed polymerization of ortho-imino-phenol: Synthesis, characterization, thermal stability and electrochemical properties

WOS: 000414214000012Enzymatic polymerization of phenols has been investigated extensively over the last decades. However, involving imine functional group in the side chain of an oligophenol and its effect on polymerization is poorly understood. Therefore, the influence of the imine functionality in the side chain of oligophenol for enzymatic polymerization is explored in this work. Ortho-imine substituted phenol, (E)-2-((p-tolylimino) methyl) phenol (PTIMP), was enzymatically polymerized using horseradish peroxidase (HRP) enzyme in aqueous organic solvents and hydrogen peroxide (H2O2) as an oxidant. Different parameters (solvent system, pH and reaction temperature) on polymerization were investigated. EtOH/pH 6.0 buffer (50: 50 vol.%) at 25 degrees C in 24 h under air was found to be the optimum polymerization condition with 65% of yield and Mn = 6100 g/mol (DP approximate to 29, PDI = 1.09). Polymerization of PTIMP in the presence of HRP enzyme catalyst leads to the formation of an oligophenol containing phenylene and oxyphenylene repeat units. The resulting oligophenol is soluble in most of the organic solvents. Characterization of oligo(PTIMP) was achieved by NMR, UV-Vis, CV, FT-IR spectroscopy and thermogravimetric analysis. (C) 2017 King Saud University. Production and hosting by Elsevier B. V. This is an open access article under the CC BY-NC-ND license.scientific research fund of Erciyes University - Turkey [FBA-2016-6611]This research was supported by scientific research fund of Erciyes University - Turkey (FBA-2016-6611). We would also like to thank retired Prof. Dr. Huseyin Yuruk for sharing his valuable comments with us during the research

Polypyrrole/multi-walled carbon nanotube composite for the solid phase extraction of lead(II) in water samples

WOS: 000331670700063PubMed ID: 24401439A multi-walled carbon nanotubes-polypyrrole conducting polymer nanocomposite has been synthesized, characterized and used for the separation and preconcentration of lead at trace levels in water samples prior to its flame atomic absorption spectrometric detection. The analytical parameters like pH, sample volume, eluent, sample flow rate that were affected the retentions of lead(II) on the new nanocomposite were optimized. Matrix effects were also investigated. Limit of detection and preconcentration factors were 1.1 mu g L-1 and 200, respectively. The adsorption capacity of the nanocomposite was 25.0 mg lead(II) per gram composite. The validation of the method was checked by using SPS-WW2 Waste water Level 2 certified reference material. The method was applied to the determination of lead in water samples with satisfactory results. (C) 2013 Elsevier B.V. All rights reserved.Erciyes University; Nigde UniversityThe authors are grateful for the financial support of the Units of the Scientific Research Project of Erciyes University and Nigde University

Synthesis and Characterization of Conducting Copolymers of Quinoxaline Derivatives

WOS: 000288142700060Electrochemical copolymerizations of 2,3-di(2-thienyl)quinoxaline (M1), 6-methyl-2,3-di(2-thienyl)quinoxaline (M2), and 2,3-di(2-thienyl)quinoxaline-6-yl)(phenyl)methanone (M3) with 3,4-ethylenedioxy thiophene (EDOT) were carried out in CH3CN/TBABF(4) (0.1M) solvent-electrolyte couple via potentiodynamic electrolysis. The obtained copolymers were characterized by cyclic voltammetry (CV), Fourier transform-infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetry analyses (TGA). The conductivity measurements of copolymers and PEDOT were performed by the four-probe technique. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 120: 1713-1719, 2011Research Foundation of Nigde University (Nigde-Turkey), TUBAContract grant sponsors: Research Foundation of Nigde University (FEB 2007-11) (Nigde-Turkey), TUBA

Synthesis and characterization of imine-functionalized polyphenol via enzymatic oxidative polycondensation of a bisphenol derivative

WOS: 000370352800011Enzymatic oxidative polycondensation of a new bisphenol derivative 3,3'-((1E,1'E)-(1,3-phenylenebis(azanylylidene))bis(methanylylidene))diphenol, (3,3'-PBAMD), using horseradish peroxidase (HRP) enzyme and hydrogen peroxide (H2O2) oxidizer for initiation of the reaction, has been investigated in an equivolume mixture of an organic solvent (acetone, methanol, ethanol, dichloromethane, 1,4-dioxane and tetrahydrofuran) and phosphate buffer (pH = 5.0, 6.0, 7.0, 8.0 and 9.0) at different temperatures under air for 24 h. The resulting polymer, poly(3,3'-PBAMD), was characterized using ultraviolet-visible (UV-Vis), Fourier transform infrared (FT-IR), H-1 nuclear magnetic resonance (NMR), gel permeation chromatography (GPC) and thermogravimetric (TGA) analyses. Effects of solvent system, reaction temperature and pH on the polymerization have been investigated with respect to the yield and molecular weight (M-n) of the product. The optimum reaction condition in terms of the highest yield (81 %) and molecular weight (M-n = 10,500 g/mol, DP similar to 33) was achieved in an equivolume mixture of tetrahydrofuran/pH 7.0 phosphate buffer medium at 25 degrees C. Polymerization involved hydrogen elimination from the monomer, and terminal units of the polymer structure consisted of phenolic hydroxyl (-OH) groups at the ends. The polymer is mainly composed of a mixture of phenylene and oxyphenylene units according to H-1 NMR and FT-IR analyses. The resulted product has shown relatively high thermal stability against thermal decomposition, and 35 % of the initial weight of the sample (carbonaceous residue) remained after heating to 1000 degrees C.Turkish Ministry of National EducationE. G. graciously acknowledges the Turkish Ministry of National Education for his Ph.D. scholarship

Electrochemical Synthesis of a Water-Soluble and Self-Doped Polythiophene Derivative

A new monomer, 4-(thiophen-3-yl methyleneamino)benzene sulfonate) (ThSA), was synthesized and characterized. Electrochemical polymerization of ThSA yields a water-soluble and self-doped polymer (PThSA). This polymer was characterized by FT-IR, NMR, DSC, XRD and conductivity measurements. (C) Koninklijke Brill NV, Leiden, 200

Synthesis and characterization of conducting graft copolymers based on oligophenols

Oligo-2-aminophenol (OAF) was synthesized with oxidative polycondensation of 2-aminophenol and hydrogen peroxide in an aqueous alkaline medium at 80 degrees C. Oligo-2-aminophenol with thiophene side groups (TOAF) was obtained by the reaction of OAF and thiophene-3-acetic acid. Graft copolymers of TOAF and pyrrole were synthesized by electrochemical polymerization in p-toluene sulfonic acid (PTSA)/water medium. Characterization of the graft copolymer (TOAF-g-Py), was carried out by combination of techniques including thermal gravimetry (TGA), cyclic voltametry, size-exclusion chromatography, H-1-NMR and FTIR. The conductivities were measured by the four-probe technique

Highly compressible binder-free sponge supercapacitor electrode based on flower-like NiO/MnO2/CNT

The increasing demand for flexible electronics encourages the innovative and functional designs of electrode materials with high performance and compressibility. In this work, we report a compressible supercapacitor electrode which is prepared by coating electrically active NiO/MnO2/carbon nanotube (CNT) composite onto a sponge. A cube of sugar was used as the template to obtain the sponge through infiltration and cross-linking of polydimethylsiloxane (PDMS). NiO/MnO2/CNT was deposited on the PDMS sponge to generate substantial amount of interface, resulting in a specific capacitance of 23 F/g at 0.1 A /g in a three-electrode system and 1.32 F/g at 0.5 mA in a symmetric supercapacitor. The proposed system exhibits excellent cycling stability with capacitance retention over 10.000 cycles. The strong adhesion of the binary metal oxides and carbon material onto the porous nonconductive sponge enables mechanical stability under compression-release cycles. Our study indicates that this electrode is a promising candidate for applications in flexible electronics. Furthermore, this research might guide the development of flexible, high-performance, and low-cost electrodes, which will be useful in wearable energy storage systems. (C) 2022 Published by Elsevier B.V