Yazar "Kahya, Nilay" seçeneğine göre listele

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    Öğe
    Adsorptive removal kinetics of anionic dye onto chitosan films doped with graphene oxide: An in situ fluorescence monitoring
    (Taylor & Francis Inc, 2018) Kahya, Nilay; Bener, Semira; Kaygusuz, Hakan; Evingur, Gulsen Akin; Erim, F. Bedia
    The aqueous adsorption of a fluorescent dye (pyranine) onto crosslinked chitosan-graphene oxide composite films was studied. In situ fluorescence monitoring technique is introduced as easy and fast experimental technique to select optimal adsorbent conditions. The effect of ionic crosslinker on adsorption was studied with sodium tripolyphosphate, trisodium citrate, and sodium sulfate, respectively. Among the crosslinkers, it was realized that sodium sulfate crosslinked films showed a greater adsorption rate for pyranine than the other two types of crosslinked films. Recently, graphene oxide is of interest as a filler compound for many biopolymer applications due to its favorable thermal, mechanical and surficial properties. In the present study, graphene oxide incorporation increased adsorption rate of the dye and the mechanical strength of ionically crosslinked chitosan films. The adsorption behavior of the adsorbent was explained by a kinetic model. Samples were characterized using scanning electron microscopy, thermogravimetric analysis, swelling experiments and tensile testing method.
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    Öğe
    Antibacterial nano cerium oxide/chitosan/cellulose acetate composite films as potential wound dressing
    (Pergamon-Elsevier Science Ltd, 2020) Kalaycıoğlu, Zeynep; Kahya, Nilay; Adımcılar, Veselina; Kaygusuz, Hakan; Torlak, Emrah; Akın-Evingür, Gülşen; Erim, F. Bedia
    Novel chitosan and cellulose acetate polymer composites with nanosized cerium oxide were prepared as potential wound dressing materials. Chitosan and cellulose acetate are natural polymer derivatives with biocompatible properties. Both polymers can be dissolved in formic acid. The polymer composite was formed by solvent-casting method. The formed films were not soluble in water. In order to improve antibacterial, thermal, and mechanical properties of the composite material, films were loaded with nanosized cerium oxide. Films were characterized with thermogravimetric, scanning electron microscopy with energy-dispersive X-ray spectroscopy, mechanical, ultraviolet-visible light transmittance, water solubility, pH, moisture content, water vapor transmission rate, swelling, and antibacterial tests. The physical properties and antibacterial characteristics of the films are promising for further research as a potential wound covering material.
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    Öğe
    Effective photocatalytic degradation of malachite green dye by Fe(III)-Cross-linked alginate-carboxymethyl cellulose composites
    (2022) Karadeniz, Duygu; Kahya, Nilay; Erim, F. Bedia
    Fe(III) ion cross-linked alginate-carboxymethyl cellulose composite beads (Fe@(Alg-CMC)) were prepared and used as a novel photocatalyst for the degradation of malachite green (MG) dye. Fe (III) ions bound to the carboxyl groups of the biopolymer composite provided reactive radicals under UV light, and degradation of the dye in an aqueous solution occurred at a high percentage and in a short time. Unlike Fenton’s reaction, effective degra- dation of the dye was carried out without adding H2O2 to the medium. Optimum conditions of dye degradation were investigated. Under UV-A light, 98.8%±0.7% dye degradation was achieved at pH 4 of 10 ppm MG solution with 0.1 g of Fe@(Alg-CMC) beads in 30 min. Experimental results fitted Langmuir-Hinshelwood kinetic modeling, which explains the kinetics of the heterogeneous catalytic processes. A rate constant (k) of 0.115 ± 0.001 min