Yazar "Tezel, Ruhiye Nilay" seçeneğine göre listele

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    Development of chitosan nanoparticle loaded with Tricholoma fracticum extract and evaluation of in vitro antioxidant activity
    (Wiley, 2024) Canbolat, Fadime; Acar, Ismail; Tezel, Ruhiye Nilay
    The objective of this study was to develop Tricholoma fracticum extract-loaded chitosan nanoparticles (TFNPs) by ionic gelation method and to evaluate their in vitro antioxidant activity. Phenolic and flavonoid contents in the T. fracticum extract were measured spectrophotometrically and chromatographically. Characterisation of NPs was evaluated by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), ZETA analysis, Fourier-transform infrared spectroscopy (FT-IR), UV-visible spectroscopy (UV-Vis) and thermogravimetric analysis (TGA). In vitro antioxidant capacity was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2 '-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. The phenolic and flavonoid contents in the T. fracticum extract were measured as 7.1 +/- 0.3 mg Gallic Acid Equivalent/g extract and 5.5 +/- 0.6 mg Quercetin Equivalent/g extract, respectively. The particle size, polydispersity index (PDI) and zeta potential of Blank NP1 and TFNP were 265.5 +/- 15.8 nm, 0.4, 38.7 +/- 4.0 mV and 333.2 +/- 16.3 nm, 0.4, 37.0 +/- 4.1 mV, respectively. The highest antioxidant activity was observed in TFNP, followed by T. fracticum extract, chitosan and blank NP, respectively. The preserved or enhanced antioxidant activity observed in the encapsulated T. fracticum extract indicates the potential for loading similar mushroom extracts onto chitosan and thus preserving their bioactive properties.
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    Facile chemical route to copper/polymer composite: Simultaneous reduction and polymerization
    (Elsevier Science Bv, 2014) Bilici, Ali; Tezel, Ruhiye Nilay; Kaya, İsmet
    The oxidation of 6-aminoquinoline (AQ) with the cupric sulphate solution yielded the formation of core-shell organic-inorganic composite, consisting of copper particles and poly(6-aminoquinoline) (PAQ) matrix. The resulting composite (PAQ/Cu) was characterized by UV-Vis, FT-IR, SEM, TEM, X-RD, XPS, cyclic voltammetry (CV), thermogravimetry (TG), fluorescence and solid state conductivity measurements. Optic band gap (E-opt) of composite determined by Tauch equality was 3.98 eV. From fluorescence analysis, it was revealed the presence of a solvatochromic phenomenon. Current-voltage (I-V) characteristics of PAQ/Cu were determined. As a novel photocatalytic material, photocatalytic performance of composite was also investigated for degradation of methylene blue (MB) under UV irradiation. (C) 2014 Elsevier B.V. All rights reserved.
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    Fenotiyazin birimi içeren polimerlerin sentezi ve karakterizasyonu
    (Çanakkale Onsekiz Mart Üniversitesi, 2016) Tezel, Ruhiye Nilay; Kaya, İsmet
    Bu tez çalışmasında fenotiyazin birimi içeren alifatik ve aromatik köprülü monomerler sentezlendi ve oksidatif polimerizasyon aracılığıyla karşılık gelen polimerlerine dönüştürüldü. Sentezlenen monomer ve polimerlerin yapıları FT-IR, 1H-NMR, 13C-NMR spektral teknikleri ile belirlendi. Monomer ve polimerlerin optik özellikleri UV-Vis ve floresans spektroskopisi yöntemleriyle belirlendi. Sentezlenen maddelerin elektrokimyasal özellikleri döngüsel voltametri tekniği ile belirlendi. Döngüsel voltametri ve UV-Vis spektrumları kullanılarak monomer ve polimerlerin HOMO (En Yüksek Enerjili Dolu Molekül Orbitali), LUMO (En Düşük Enerjili Boş Molekül Orbitali) enerji seviyeleri ile elektrokimyasal (Eg') ve optik (Eg) band boşluğu değerleri hesaplandı. Sentezlenen monomer ve polimerlerin termal özellikleri TG-DTA ve DSC teknikleriyle araştırıldı. Polimerlerin ortalama mol kütlesi dağılımları GPC analizleriyle belirlendi. Ek olarak sentezlenen polimerlerin morfolojik özellikleri SEM analizleri ile belirlendi. Sentezlenen bileşiklerin yapılarındaki farklı alifatik ve aromatik gruplara bağlı olarak fotofiziksel, elektrokimyasal, morfolojik ve ısısal özelliklerindeki farklılıklar araştırıldı.
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    Peroxidase/H2O2 catalyzed oxidative oligomerization of 1-aminopyrene
    (Taylor & Francis Inc, 2017) Kaya, İsmet; Bilici, Ali; Tezel, Ruhiye Nilay; Temizkan, Kevser; Doğan, Fatih
    A new florescent oligo(aminopyrene) (OAP) was successfully synthesized by enzymatic approach. For this, H2O2 and Horse Radish peroxidase (HRP) were used as catalyst and oxidant, respectively. The structures of monomer and oxidation product were confirmed by NMR, FT-IR and UV-Vis measurements. The oxidation product was characterized by gel permeation chromatography (GPC), thermogravimetry (TG), differential scanning calorimetry (DSC), cyclic voltammetry (CV), photoluminescence (PL) and scanning electron microscopy (SEM) analyses. OAP was soluble in a wide range of organic solvents. UV-Vis spectrum of the OAP showed a dramatic red shift compared to that of the monomer. The optical and electrochemical band gaps of OAP were found to be 1.65 and 1.56 eV, respectively. OAP emitted turquoise color in THF and green color in toluene. SEM observations indicated the presence of a heterogeneous cauliflower like morphology.
  • Küçük Resim
    Öğe
    Synthesis and Characterization and Thermal Decomposition Kinetics of Poly (quinoline)-Copper Composite
    (2018) Bilici, Ali; Tezel, Ruhiye Nilay; Kaya, İsmet; Doğan, Fatih
    In here, chemical oxidative synthesis of a new poly(quinoline)-coppercomposite was given in one-step pathway. To obtain composite, the coppersulphate and 2-amino-8-quinolinol were used as oxidant and monomer,respectively. The oxidation product obtained was characterized by FTIR, UV-Vis,thermogravimetry (TG), photoluminescence (PL), SEM-EDX, TEM analysis and solidstate conductivity measurements. SEM observations exhibited the presence of a plate-like heterogeneousmorphology. Rod like structures was revealed from TEM images. TEM studies also indicated that the coppernanoparticles were almost uniformly distributed on polymer. The thermaldecomposition kinetics of oxidation product were also studied. For this, the differentmethods such as Coats-Redfern, Flynn-Wall-Ozawa, Tang and Kissinger-Akahira-Sunose were used.
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    Thiophene substituted phenothiazine polymers: Design, synthesis and characterization
    (Elsevier, 2020) Tezel, Ruhiye Nilay; Kaya, İsmet
    In this paper, the polymers containing phenothiazine were synthesized via oxidative polymerization reaction by FeCl3 as oxidant. These polymers contain ether unit, aliphatic chain and aromatic groups as bridges in their structures. The effects of the groups on the optical, thermal, morphological properties of the polymers were investigated. The physical and chemical properties of the monomers and the polymers were identified by FT-IR, NMR, UV-Vis, thermogravimetry (TG), cyclic voltammetry (CV), fluorescence analysis. According to the fluorescence analyses, polymer containing aliphatic ether bridge emitted yellow colour based on the turning of excitation wavelength. The yellow solution of polymer containing aliphatic ether bridge turned into turquoise when excited with the wavelength of 365 nm. Thermal analyses demonstrated that polymer containing phenyl bridge compound had 38% residue amount. Due to fluorescent and thermal properties, these polymers could be used in various applications such as spectrofluorometric ion sensor and polymeric light emitting diodes (PLEDs) with yellow and turquoise emissions. (C) 2018 Production and hosting by Elsevier B.V. on behalf of King Saud University.