Yazar "Koc, Omer Kaan" seçeneğine göre listele

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    A simple azoquinoline based highly selective colorimetric sensor for CN- anion in aqueous media
    (Canadian Science Publishing, Nrc Research Press, 2017) Koc, Omer Kaan; Ozay, Hava
    Azoquinoline based sensor AZQ was designed and synthesized as a new molecular ion sensor containing an azo group in its structure. The structural characterization of AZQ was carried out using FTIR, NMR, mass, and elemental analysis. Then, the interaction of AZQ with anions was observed visually and UV-vis measurements were made in EtOH/H2O (1:1, v/v) solvent mixture. As a result of this investigation, it was determined that AZQ is a fast and highly selective sensor for CN-ions. The solution colour of AZQ changed from light yellow to orange only in the presence of CN-ions. The limit of detection of AZQ was calculated as 2.6 mu mol/L from anion titration experiments. Also, to identify the interaction mechanism of AZQ with CN-ions, H-1 NMR spectra of AZQ in the presence of CN-anions were recorded and the structure was proposed for AZQ-CN- host-guest complex.
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    Öğe
    The preparation and applications of novel phosphazene crosslinked thermo and pH responsive hydrogels
    (Elsevier Science Inc, 2016) Ozay, Hava; Sahin, Ozdem; Koc, Omer Kaan; Özay, Özgür
    In this study, we synthesized a novel phosphazene compound hexakis[4-(acrylamido)phenoxy] cyclotriphosphazene (HAAP) as crosslinker. The structure of compound was identified using spectroscopic techniques. Then, HAAP was used as crosslinker for the synthesis of thermo and pH responsive p(NIPAM-co-VI) hydrogels. The structure and swelling behavior of hydrogel was investigated. Then, HAAP-crosslinked p(NIPAM-co-VI) hydrogels were used for in vitro release of Rhodamine 6G as drug release matrix. Additionally, HAAP-crosslinked p(NIPAM-co-VI) hydrogels were used as support material for the preparation of cobalt metal catalysts. The prepared HAAP-crosslinked p(NIPAM-co-VI)Co composite catalyst was used as catalyst for the reduction reaction of 4-nitrophenol. (C) 2016 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
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    The Preparation of Phosphazene Crosslinked Cyclen Microspheres as Host for Cu2+ Ions and Their Utilization as a Support Material for the Preparation of a Copper Nanocatalyst
    (Springer, 2017) Sahin, Ozdem; Koc, Omer Kaan; Ozay, Hava; Özay, Özgür
    In this study firstly, phosphazene crosslinked cyclen microspheres were synthesized. Then, supported copper nanoparticles were prepared on these phosphazene crosslinked cyclen microspheres for use as a metal catalyst. The prepared microparticles and microparticle-supported metal catalyst were characterized using FT-IR, SEM-EDX, TEM and XPS analysis. Also, the prepared metal composite was used as a catalyst for the reduction reaction of 4-nitrophenol in the presence of NaBH4 in aqueous media. The catalytic activity of the Cu-cyclen composite catalyst was investigated using UV-Vis spectroscopy. The reduction studies were completed at four different temperatures (30-60 A degrees C). The activation parameters were calculated from the obtained rate constants at the four different temperatures (30-60 A degrees C). The activation energy, activation enthalpy and activation entropy for the reduction reaction of 4-NP in the presence of Cu-cyclen composite catalyst were calculated as 39.88, 36.56 and -143.30 kJmol(-1), respectively. The total turnover frequency (TOF) for Cu-cyclen composite catalyst was 0.794 mol 4-NP (mol Cu)(-1) (min)(-1).