PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collections

Permanent URI for this collectionhttps://hdl.handle.net/20.500.13091/5

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Now showing 1 - 7 of 7

Citation - WoS: 2
Citation - Scopus: 2
Calixarene-Based Functional Fabric for Simultaneously Adsorptive Removal of Anionic and Cationic Dyes
(Amer Chemical Soc, 2025) Ozcelik, Egemen; Tabakci, Begum; Karaman, Mustafa; Tabakci, Mustafa
This study investigated the adsorptive properties of functionalized fabric containing dimethylaminomethyl calix[4]arene (DMAM-Calix) to remove anionic methyl orange (MO) and cationic Rhodamine B (RhB) dyes in aqueous media. Adsorption studies were performed using a filtration system packed with DMAM-Calix-functionalized fabric (DCF). The results revealed that the cationic and anionic structures work compatibly in a binary mixture medium. Hydrogen bonding, pi-pi, cation-pi, n-pi and electrostatic interactions between dye molecules and DMAM-Calix units of DCF were the main factors affecting the adsorption process. Experiments on real wastewater samples of unknown composition confirmed that the approach could successfully remove MO and RhB dyes from real water samples with high efficiency, especially for RhB. Isotherm and kinetic data for MO were mainly represented by the Langmuir model and pseudo-second-order kinetic model, respectively. The adsorption capacities of DCF were found to be about 4.7 mg g-1 for MO and 1.0 mg g-1 for RhB at pH 6.0, which were evaluated as satisfactory considering the first use of a calixarene-derived coated fabric as an adsorbent, the anionic-cationic dye selectivity of DCF, and the low cost and ease of application of the method.
Citation - WoS: 12
Citation - Scopus: 16
Characterization of Polysaccharide Extracts of Four Edible Mushrooms and Determination of in Vitro Antioxidant, Enzyme Inhibition and Anticancer Activities
(Amer Chemical Soc, 2024) Deveci, Ebru; Tel-Cayan, Gülsen; Cayan, Fatih; Altinok, Bahar Yilmaz; Aktaş, Sinan
Mushroom polysaccharides are important bioactive compounds derived from mushrooms with various beneficial properties. In this study, the chemical characterization and bioactivities of polysaccharide extracts from four different edible mushrooms, Clavariadelphus truncatus Donk, Craterellus tubaeformis (Fr.) Quel., Hygrophorus pudorinus (Fr.) Fr., and Macrolepiota procera (Scop.) Singer were studied. Glucose (13.24-56.02%), galactose (14.18-64.05%), mannose (2.18-18.13%), fucose (1.21-5.78%), and arabinose (0.04-5.43%) were identified in all polysaccharide extracts by GC-MS (gas chromatography-mass spectrometry). FT-IR (Fourier transform infrared spectroscopy) confirmed the presence of characteristic carbohydrate patterns. H-1 NMR suggested that all polysaccharide extracts had alpha- and beta-d-mannopyranose, d-glucopyranose, d-galactopyranose, alpha-l-arabinofuranose, and alpha-l-fucopyranose residues. Approximate molecular weights of polysaccharide extracts were determined by HPLC (high-performance liquid chromatography). The best antioxidant activity was found in M. procera polysaccharide extract in DPPH center dot (1,1-diphenyl-2-picrylhydrazyl) scavenging (39.03% at 800 mu g/mL), CUPRAC (cupric reducing antioxidant capacity) (A(0.50): 387.50 mu g/mL), and PRAP (phosphomolybdenum reducing antioxidant power) (A(0.50): 384.08 mu g/mL) assays. C. truncatus polysaccharide extract showed the highest antioxidant activity in ABTS(center dot+) scavenging (IC50: 734.09 mu g/mL), beta-carotene-linoleic acid (IC50: 472.16 mu g/mL), and iron chelating (IC50: 180.35 mu g/mL) assays. Significant anticancer activity was found in C. truncatus polysaccharide extract on HT-29 (IC50: 46.49 mu g/mL) and HepG2 (IC50: 48.50 mu g/mL) cell lines and H. pudorinus polysaccharide extract on the HeLa cell line (IC50: 51.64 mu g/mL). Also, H. pudorinus polysaccharide extract possessed prominent AChE (acetylcholinesterase) inhibition activity (49.14% at 200 mu g/mL).
Citation - WoS: 18
Citation - Scopus: 19
Development of Highly Luminescent Water-Insoluble Carbon Dots by Using Calix[4]pyrrole as the Carbon Precursor and Their Potential Application in Organic Solar Cells
(Amer Chemical Soc, 2022) Coşkun, Yağız; Ünlü, Fatma Yelda; Yılmaz, Tuğbahan; Türker, Yurdanur; Aydoğan, Abdullah; Kuş, Mahmut; Ünlü, Caner
Carbon dots (CDs) are carbon-based fluorescent nanomaterials that are of interest in different research areas due to their low cost production and low toxicity. Considering their unique photophysical properties, hydrophobic/amphiphilic CDs are powerful alternatives to metal-based quantum dots in LED and photovoltaic cell designs. On the other hand, CDs possess a considerably high amount of surface defects that give rise to two significant drawbacks: (1) causing decrease in quantum yield (QY), a crucial drawback that limits their utilization in LEDs, and (2) affecting the efficiency of charge transfer, a significant factor that limits the use of CDs in photovoltaic cells. In this study, we synthesized highly luminescent, water-insoluble, slightly amphiphilic CDs by using a macrocyclic compound, calix[4]pyrrole, for the first time in the literature. Calix[4]pyrrole-derived CDs (CP-DOTs) were highly luminescent with a QY of over 60% and size of around 4-10 nm with graphitic structure. The high quantum yield of CP-DOTs indicated that they had less amount of surface defects. Furthermore, CP-DOTs were used as an additive in the active layer of organic solar cells (OSC). The photovoltaic parameters of OSCs improved upon addition of CDs. Our results indicated that calix[4]pyrrole is an excellent carbon precursor to synthesize highly luminescent and water-insoluble carbon dots, and CDs derived from calix[4]pyrrole are excellent candidates to improve optoelectronic devices.
Citation - WoS: 20
Citation - Scopus: 19
Electrical and Photodetector Characteristics of Schottky Structures Interlaid With P(eha) and P(eha-Co Functional Polymers by the Icvd Method
(Amer Chemical Soc, 2023) Demirezen, Selcuk; Ulusoy, Murat; Durmuş, Haziret; Çavuşoğlu, Halit; Yılmaz, Kurtuluş; Altındal, Şemsettin
In this study, poly(2-ethylhexyl acrylate) (PEHA) homopolymer and its copolymer combined with acrylic acid P(EHA-co-AA) were employed as interfaces in two separate Schottky structures. First, both interfaces were grown by initiated chemical vapor deposition (iCVD), which provides much better deposition control and homogeneous coating compared to solution-phase methods. In addition to this advantageous method, the effects of two different polymers, one of which is better able to adhere to the crystal surface on which it is formed than the other, on the optoelectronic properties have been studied. Then, their current-voltage (I-V) and capacitance/conductance-voltage (C/(G/omega)-V) characteristics were investigated both in the dark and under illumination. The basic electrical parameters and the illumination-induced profile of the surface state (N-ss) were probed by I-V and C-V measurements for two samples. A decrease in the barrier height (BH) and, consequently, a significant increase in the photocurrent were observed under illumination. Striking changes in series resistance (R-s) values are also highlighted. The photocapacitance and conductance characteristics indicated that the structures could be considered not only as photodiodes but also as photocapacitors. Moreover, the voltage-dependent changes of some photodetector parameters, such as responsivity (R), sensitivity (S), and specific detectivity (D*), along with the transient photocurrent characteristics, are discussed for both structures. Therefore, we can say that the strong changes in these parameters, which figure the merit of photodiode and photodetector applications, depending on the voltage and under illumination, prove that it is a study carried out in accordance with the purpose and so they can be used in electronic and optoelectronic applications.
Citation - WoS: 5
Citation - Scopus: 4
Environmentally Friendly and All-Dry Hydrophobic Patterning of Graphene Oxide for Fog Harvesting
(Amer Chemical Soc, 2024) Yılmaz, Kurtuluş; Gürsoy, Mehmet; Karaman, Mustafa
This study examines the fog-harvesting ability of graphene oxide surfaces patterned by hydrophobic domains. The samples were prepared from graphene deposited using low pressure chemical vapor deposition, which was later plasma oxidized to obtain hydrophilic graphene oxide (GO) surfaces. Hydrophobic domains on GO surfaces were formed by initiated CVD (iCVD) of a low-surface-energy poly(perfluorodecyl alkylate) (PPFDA) polymer. Hence, patterned surfaces with hydrophobic/hydrophilic contrast were produced with ease in an all-dry manner. The structures of the as-deposited graphene and PPFDA films were characterized using Raman and Fourier transform infrared spectrophotometer analyses, respectively. The fog harvesting performance of the samples was measured using the fog generated by a nebulizer, in which the average diameter of the fog droplets is comparable to meteorological fog. According to the fog harvesting experiment results, 100 cm2 of the as-patterned surface can collect fog up to 2.5 L in 10 h in a foggy environment. Hence, hydrophilic/hydrophobic patterned surfaces in this study can be considered as promising fog harvesting materials. Both CVD techniques used in the production of hydrophilic/hydrophobic patterned surfaces can be easily applied to the production of large-scale materials.
Preparation and Characterization of the Mmt@fe₃o_{4< Nanocomposite for Catalytic Degradation of Methyl Yellow: Reaction Parameters and Mechanism Based on the Artificial Neuron Network}
(Amer Chemical Soc, 2025) Altun, Turkan; Acar, Musa Kazim; Gubbuk, Ilkay Hilal
The montmorillonite@iron oxide@silver (MMT@Fe3O4@Ag) nanocomposite, which is recyclable and exhibits high catalytic activity, was evaluated for the degradation of methyl yellow (MY), a carcinogenic azo dye. For this purpose, MMT@Fe3O4 was first synthesized via the coprecipitation method and then Ag was doped to MMT@Fe3O4 via the chemical reduction method. MMT, MMT@Fe3O4, and MMT@Fe3O4@Ag were characterized by various techniques including scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, vibrating sample magnetometer, and thermal gravimetric analysis. The results illustrated that MMT@Fe3O4@Ag exhibited a higher catalytic ability than MMT@Fe3O4 toward decolorization of MY with a degradation efficiency of 100% in 10 min at pH 7.1 in the presence of sodium borohydride (NaBH4). Further, some parameters like the amount of NaBH4, initial dye concentration, and pH were also studied to determine optimum reaction conditions. MMT@Fe3O4@Ag could be easily separated and recycled from the reaction medium using an external magnet. Thus, the Ag-doped MMT@Fe3O4 nanocomposite proved to have good catalytic activity, high MY degradation rate and reusability, and easy separation and simple synthesis method. These properties make it a promising catalyst for the treatment of wastewater containing organic pollutants. In addition, artificial neural network (ANN) simulation, which is a mathematical model with an artificial intelligence algorithm, was used for the degradation process. This model was evaluated with the parameters used in the experiment as the input and output layers. Last, the degradation of MY with the synthesized catalyst into different products was demonstrated by high-performance liquid chromatography (HPLC) analysis.
Citation - WoS: 9
Citation - Scopus: 9
Reactive Extraction of Betaine From Sugarbeet Processing Byproducts
(Amer Chemical Soc, 2023) Altinisik, Sinem; Zeidan, Hani; Yilmaz, M. Deniz; Marti, Mustafa E.
Betaine from natural sources is still preferred over its synthetic analogue in secondary industries. It is currently obtained by expensive separation means, which is one of the main reasons for its high cost. In this study, reactive extraction of betaine from sugarbeet industry byproducts, that is, molasses and vinasse, was investigated. Dinonylnaphthalenedisulfonic acid (DNNDSA) was used as the extraction agent, and the initial concentration of betaine in the aqueous solutions of byproducts was adjusted to 0.1 M. Although maximum efficiencies were obtained at unadjusted pH values (pH 6, 5, and 6 for aqueous betaine, molasses, and vinasse solutions, respectively), the effect of aqueous pH on betaine extraction was negligible in the range of 2-12. The possible reaction mechanisms between betaine and DNNDSA under acidic, neutral, and basic conditions were discussed. Increasing the extractant concentration significantly increased (especially in the range of 0.1-0.4 M) the yields, and temperature positively (but slightly) affected betaine extraction. The highest extraction efficiencies (similar to 71.5, 71, and 67.5% in a single step for aqueous betaine, vinasse, and molasses solutions, respectively) were obtained with toluene as an organic phase solvent, and it was followed by dimethyl phthalate, 1-octanol, or methyl isobutyl ketone, indicating that the efficiency increased with decreasing polarity. Recoveries from pure betaine solutions were higher (especially at higher pH values and [DNNDSA] < 0.5 M) than those from vinasse and molasses solutions, indicating the adverse influence of byproduct constituents; however, the lower yields were not due to sucrose. Stripping was affected by the type of organic phase solvent, and a significant amount (66-91% in single step) of betaine in the organic phase was transferred to the second aqueous phase using NaOH as the stripping agent. Reactive extraction has a great potential for use in betaine recovery due to its high efficiency, simplicity, low energy demand, and cost.

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