Person: KAHRAMAN, MEMET VEZİR
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KAHRAMAN
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MEMET VEZİR
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Publication Metadata only Covalently bonded nanosilver-hydroxyethyl cellulose/polyacrylic acid/sorbitol hybrid matrix: thermal, morphological and antibacterial properties(SPRINGER, 2022) BİRTANE, HATİCE; Cigil, Asli Beyler; Sen, Ferhat; Birtane, Hatice; Kahraman, Memet VezirIn this study, an antibacterial, biodegradable, biocompatible, and environmentally friendly coating was prepared with an easy technique. Accordingly, Ag nanoparticles were synthesized to provide antibacterial properties to the coating, and its surface was modified with (3-Glycidyloxypropyl)trimethoxysilane (GPTMS) in order not to clump in the coating, to ensure homogeneous distribution on the surface, and to covalently bond to the coating. While preparing the coating formulation, polyacrylic acid (PAA), which are natural polymers, and hydroxyethyl cellulose (HEC), a derivative of cellulose, were preferred to reduce the consumption of petroleum derivatives. Then, sorbitol was used as a plasticizer. Synthesized Ag nanoparticles were included in the coating formulation containing PAA/HEC and sorbitol and thermally crosslinked at a high temperature. The size of Ag nanoparticles was analyzed by DLS while chemical composition after modification was analyzed by FTIR. Then, the chemical structure, thermal properties, surface properties, and antibacterial properties of the environmentally-friendly film were examined. It was observed that Ag nanoparticles, the surface of which were modified with GPTMS containing silicon groups, increased the thermal stability of the film, and the presence of Si and Ag on the surface was detected in SEM-EDAX measurements, and this showed that the aimed coating was obtained. It was observed that silver nanoparticles, of which their surface was modified, incorporated into the coating obtained from PAA and HEC, which are known to have no antibacterial properties, showed antibacterial activity against E. coli and S. aureus. The zone of inhibition was measured as 11 mm for both E. coli and S. aureus.Publication Metadata only Cellulose/cysteine based thiol-ene UV cured adsorbent: removal of silver (I) ions from aqueous solution(SPRINGER, 2021) BİRTANE, HATİCE; Cigil, Asli Beyler; Urucu, Oya Aydin; Birtane, Hatice; Kahraman, Memet VezirIn the present study, a novel, eco-friendly, and simple polymeric adsorbent was obtained from cellulose acetate butyrate (CAB) and cysteine (Cys) to remove silver (I) ions in the presence of a thiol-ene click reaction under UV rays. Accordingly, firstly, CAB was modified with acrylate groups to turn it into a photocurable resin. Then, the acrylate modified CAB obtained with the monomer having cysteine and triacrylate group was crosslinked by thiol-ene click reaction under UV rays to obtain an eco-friendly adsorbent. The adsorbent acquired -S-, -COO and -NH2 groups as a result of this reaction and these functional groups are known to have the ability to selectively couple with Ag(I) ions. The adsorbent was evaluated for the selective removal of Ag(I) ions from aqueous samples characterized by SEM, SEM-EDAX, and FTIR. To determine the most suitable conditions, the effect of important parameters such as pH and contact time was investigated. It was determined that the most suitable isotherm for adsorption was the Langmuir isotherm (R: 0.999). The efficacy of our eco-friendly adsorbent was investigated in a real stream and lake waters and very good results were achieved. [GRAPHICS] .Publication Metadata only Antibacterial UV-photocured acrylic coatings containing quaternary ammonium salt(SPRINGER, 2021) BİRTANE, HATİCE; Birtane, Hatice; Sen, Ferhat; Bozdag, Buket; Kahraman, Memet VezirThis study aimed to develop UV-curable coating materials showing antimicrobial properties. GTAC was acrylated and characterized by FT-IR and(1)H NMR spectroscopy. UV-curable coating materials with different contents were prepared. Inhibition zone method was used to determine the antimicrobial activity of the materials. Thermal stability of samples was evaluated by TGA. Contact angles of samples were measured to obtain information about their hydrophobicity. Surface morphology of samples was investigated by SEM. Produced UV-curable coating materials have good antimicrobial, thermal and surface properties, and they can be used as antibacterial top coating material in many industries.Publication Metadata only Transparent and flexible antibacterial photocrosslinked thin films against the S. aureus and E. coli pathogen bacteria(ELSEVIER, 2021) BİRTANE, HATİCE; Beyler-Cigil, Asli; Birtane, Hatice; Sen, Ferhat; Kahraman, Memet VezirThe study aims to obtain simple, transparent, and flexible coatings that are produced using an environmentally-friendly method, have either positive or negative charge density on their surfaces, and have antibacterial properties. For this purpose, poly(ethylene glycol) diacrylate (PEGDA), trimethylolpropane triacrylate (TMPTA), and trimethylolpropane tris(3-mercaptopropionate) (TMPTMP) were crosslinked using the thiol-ene click reaction in the presence of UV light. Ammonium salt is known to have antibacterial properties due to its positively charged surface and was added to the coating formulation to positively charge the surface of the glycidyl-trimethylammonium chloride (GTMAC) coating and negatively charge the sodium 3-mercapto-1-propanesulfonate (3-MPS) surface. The thiol-ene click reaction was used in the coatings that were prepared by using the base formulation and adding 3-MPS while the thiol-ene and thiol-epoxy click reactions were used together for the addition of GTMAC to the formulation. The structural characterization of the coatings was made using FTIR, the thermal behaviors of the coatings were determined using thermogravimetric analysis (TGA), and the morphologies and chemical compositions of the coatings were examined using SEM and SEM-EDAX images. The antibacterial activities of the coatings were tested using the inhibition zone method against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria that have different cell wall properties and can serve as models for similar bacteria.Publication Metadata only Selective molecularly imprinted polymer for the analysis of chlorpyrifos in water samples(ELSEVIER SCIENCE INC, 2020) KÖK YETİMOĞLU, ECE; Urucu, Oya Aydin; Cigil, Asli Beyler; Birtane, Hatice; Yetimoglu, Ece Kok; Kahraman, Memet VezirIn this paper, a new molecularly imprinted solid-phase extraction (MISPE) method was described for the determination of the chlorpyrifos in water samples. A thiol-ene based UV-cured polymer was prepared by mixing glyoxal bis (-diallyl acetal), pentaerythritol tetrakis (3-mercaptopropionate), polyethylene glycol diacrylate (PEGDA), and photoinitiator. Chlorpyrifos was added to the prepared polymer as a template analyte, and its analysis was performed by gas chromatography with mass detection (GC-MS). The influence of some analytical parameters was studied. We found that the use of the molecularly imprinted polymer (MIP) UV-cured disc provides an easy, selective, and available solution for removing chlorpyrifos from water samples. (C) 2020 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.Publication Metadata only Thermal and dielectric properties of flexible polyimide nanocomposites with functionalized nanodiamond and silver nanoparticles(2023-05-01) BİRTANE, HATİCE; MADAKBAŞ, SEYFULLAH; ESMER, KADİR; KAHRAMAN, MEMET VEZİR; Birtane H., Cigil A. B., Madakbaş S., Esmer K., Kahraman M. V.In the present study, amine groups were first modified to diamond and silver nanoparticles using APTMS to improve their homogeneous dispersion and compatibility in polyamic acid. Flexible polyimide nanocomposite films were successfully prepared by adding modified nanodiamond and silver nanoparticles to 4,4 \"-(1,3-phenylenedioxy) dianiline and benzophenone-3,3 \",4,4 \"-tetracarboxylic dianhydrides with different proportions. The effects of added amine-modified nanoparticles on dielectric constant and thermal stability were investigated. With SEM analysis, nanoparticles were homogeneously distributed on the polyimide surface and the presence of Si atom resulting from APTMS modification is clearly seen with the SEM-EDAX results. Considering the thermal resistance, the maximum decomposition temperature of the nano particle-free PI film was found to be 501 degrees C, while the thermal decomposition temperatures of the PI nanocomposite film that contains 1% m-Ag and the PI film that contains 5% m-ND, 502 degrees C and 505 degrees C, respectively. Also, it was seen that the dielectric constants of the prepared nanocomposite films that contain m-Ag NP decrease with increasing m-Ag NP ratio, and the dielectric constants of the films that contain m-ND increase with increasing m-ND ratio.Publication Metadata only Statistical optimization and selective uptake of Au(III) from aqueous solution using carbon nanotube-cellulose based adsorbent(ELSEVIER, 2022) BİRTANE, HATİCE; Birtane, Hatice; Urucu, Oya Aydin; Yildiz, Nilgun; Cigil, Asli Beyler; Kahraman, Memet VezirIn this study, a carbon nanotube cellulose-based UV-curable nanocomposite was prepared as an adsorbent to selectively separate Au (III) ions from an aqueous medium. For this purpose, thiol-functionalized carbon nanotube and acrylate-functionalized hydroxyethyl cellulose were synthesized and the photo-curable adsorbent was obtained using the thiol-ene click reaction. The FTIR spectra revealed that the thiol groups and acrylate groups were successfully attached to carbon nanotube and hydroxyethyl cellulose, respectively. Moreover, the Scanning Electron Microscopy-Energy Dispersive X-Ray analyses showed that the photo-curable adsorbent contained sulfur atoms, thus indicating successful modification. The parameters affecting the recovery of the Au (III) ions were determined using the Plackett-Burman method. The optimum values of the parameters, which were pH, adsorption time, initial Au (III) concentration, and adsorbent amount were determined using the Box-Behnken method. The Langmuir adsorption isotherm was determined to be the best equation to describe the interaction of the Au (III) ions with the adsorbent (R-2: 0.995). The examination of the effectiveness of the photocurable adsorbent in the presence of different metal ions yielded prosperous results. Also, the developed method has been successfully applied for the recovery of Au(III) ions in river waters.