Person: KAHRAMAN, MEMET VEZİR
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KAHRAMAN
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MEMET VEZİR
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Publication Metadata only Encapsulation of trichloroacetic acid and trifluoroacetic acid for autonomous self healing coatings(TAYLOR & FRANCIS INC, 2020) KAHRAMAN, MEMET VEZİR; Tezel, Ozge; Beyler Cigil, Asli; Kahraman, Memet VezirMicrocapsules with TFA or TCA healing agents with an outer poly(melamine-urea-formaldehyde) (PMUF) were successfully synthesized for the first time, according to a review of published literature. The average sizes of the microcapsules obtained were measured to be 1.7 and 2 mu m for TFA/PMUF and TCA/PMUF, respectively. Both microcapsules were separately added to an epoxy-based coating formulation. To examine the self-healing properties, scanning electron microscopy images were examined at the moment that damage occurred and seven days later. A self-healing experiment showed that the more reactive PMUF/TFA microcapsules were more efficient than the PMUF/TCA microcapsules in repairing scratch damage in the coatings.Publication Metadata only Quaternary imidazolium-functionalized reactive silica nanoparticles-containing thiol-ene photocured antibacterial hybrid coatings(Elsevier B.V., 2022) ÇAKMAKÇI, EMRAH; Şen F., Kocatürk E., Çakmakçı E., Kahraman M.V.The need for antibacterial coatings is increasing day by day. In this study, coating materials that do not contain antibacterial agents but have antibacterial properties have been developed. First, two different quaternary imidazole compounds were synthesized. Then, silica nanoparticles were modified with these quaternary agents. By using 1%, 3% and 5% modified silica nanoparticles, UV cured coating materials were obtained according to the thiol-ene reaction mechanism. Mechanical, thermal, surface, structural, optical and antibacterial analyzes of the obtained coatings were performed. The analyzes revealed that UV cured antibacterial coating materials have been successfully synthesized and can be used as a new and unique coating material for the coating industry. © 2021 Elsevier B.V.Publication Metadata only Phosphorus Ester Containing Mesoporous Silica as Novel High-Effective Flame Retardant in Polyurethane and Polyester Coatings(WILEY-V C H VERLAG GMBH, 2021) KAHRAMAN, MEMET VEZİR; Aytan, Emre; Aytan, Tugce Akbal; Kahraman, Memet VezirIn this study mesoporous silica spheres (MPSs) and polyphosphoric acid based organophosphate ester flame retardant (FR material) material were synthesized and flame retardancy performance in acrylate-based polyurethanes (PUR) and polyester (PET) resins investigated. For this, both MPSs and FR material were synthesized according to literature and FR material was loaded into MPSs which takes the role of carrier. Loaded MPSs were put into UV curable PUR and PET resins and polymerized under UV radiation. Their characteristics were investigated by FT-IR, TGA, LOI, SEM and TEM. The results showed that FR material had excellent flame-retardant abilities for both PUR and PET series. The TGA curves suggested that synthesized FR material shows lower thermal stability at low temperatures than original materials however it showed good ability of char formation at higher temperatures, therefore improving the flame retardant property of samples. Moreover the LOI analysis showed that flame retardancy properties were improved significantly. The additive increased the LOI value from 20,5 and 21 to 26,5 and 27.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 Dimer diamin ve hint yağı esaslı bio-bazlı poliüretan köpük ve hint yağı esaslı alev geciktirici hazırlanması(2022-09-01) ÇAKMAKÇI, EMRAH; KAHRAMAN, MEMET VEZİR; Nasuhoğlu B., ÇAKMAKÇI E., KAHRAMAN M. V.Diizosiyanat ve diollerin reaksiyonu sonucu elde edilen poliüretanlar, günlük hayatımızda geniş bir kullanım alanına sahip polimerlerin başında gelmektedir. Üretilen bu ticari poliüretanlar petrol kaynaklı malzemeler kullanılarak sentezlenir[1]. Petrolün yenilenebilir bir kaynak olmamasından dolayı ve gün geçtikçe petrol fiyatlarının artmasına bağlı olarak, bu tip malzemelerin üretim fiyatının düşürülmesi ve fosil yakıtlara bağımlılığın azaltılması için polimer sentez çalışmalarında yenilebilir kaynakların kullanılması hem ekonomik hem de çevresel açıdan önemlidir. Poliüretan ham maddelerinden poliol sentezinde kullanılan yenilenebilir kaynakların başında, sentetik kimyaya en uygun malzemelerden olan bitkisel yağlar gelmektedir[2]. Bu bitkisel yağlardan yüksek doymamışlığa sahip hint yağı, keten yağı, tung yağı, ayçiçek yağı ve soya yağı bu tür çalışmalarda sıklıkla tercih edilir. Bu çalışmada, petrokimyasalları mümkün olan en az miktara indirmek amacıyla, dimer diamin ve hint yağı kullanılarak otokatalitik poliol ve hint yağı kullanılarak alev geciktirici sentezi yapılmıştır. Sentezlenen monomerler, FTIR tekniğiyle karakterize edilmiştir ve elde edilen köpüklerin mekanik testleri yapılmıştırPublication 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 Polymeric nanoparticles for selective protein recognition by using thiol-ene miniemulsion photopolymerization(TAYLOR & FRANCIS LTD, 2020) KAHRAMAN, MEMET VEZİR; Yasar, Merve; Dal Yontem, Fulya; Kahraman, M. Vezir; Apohan, Nilhan Kayaman; Aktas, Zerrin; Oncul, Mustafa Oral; Akcakaya, HandanThe fabrication of molecularly imprinted nanoparticles (MIP-NPs) specific for myoglobin by using thiol-ene photopolymerization in miniemulsion was described. Allyl derivatives of phenylalanine as a functional monomer was synthesized and copolymerized with acrylic monomersviaminiemulsion polymerization to produce NIP-NPs with approximately 74 nm number average particle diameter. FTIR and(1)H-NMR analysis confirmed the synthesis of functional monomer. MIP-NPs were prepared in the existence of myoglobin as a template protein. Morphological investigations exhibited that the particle size of the MIP-NPs, increased compared to the corresponding NIPs and the mean particle diameter by number was measured as 141 nm with narrow distribution. NIP-NPs that were polymerized without myoglobin were found to have less affinity to the target protein. In addition, the rebinding ability of MIP-NPs was much bigger than that of the corresponding NIPs. ELISA results showed that MIPs interact particularly with the myoglobin and show little affinity for BSA in competitive binding experiments.