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Öğe Adsorption of methylene blue from aqueous solution using poly(2-acrylamido-2-methyl-1-propanesulfonic acid-co-2-hydroxyethyl methacrylate) hydrogel crosslinked by activated carbon(Taylor and Francis Ltd., 2023) Ilgın, Pınar; Önder, Alper; Kıvanç, Mehmet Rıza; Özay, Hava; Özay, ÖzgürThis study aimed to develop an environmentally friendly, inexpensive, and efficient adsorbent for removing methylene blue (MB) dye from wastewater using a three-dimensional porous poly(2-Acrylamido-2-methyl-1-propanesulfonic acid-co-2-Hydroxyethyl Methacrylate), p(AMPS-co-HEMA) composite hydrogel crosslinked with vinyl-functionalized activated carbon (VAC). The surface morphology and chemical structure of the crosslinker were characterized using transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) surface area analysis, X-ray spectroscopy (XRD) and Fourier transform-infrared spectroscopy (FT-IR) instruments. The surface morphology, chemical structure and thermal properties of the hydrogel were also characterized using scanning electron microscopy (SEM), FT-IR and thermogravimetric analyzers (TGA). Experimental parameters affecting the adsorption behavior, such as initial dye concentration, time, dosage, pH, and temperature, were systematically investigated. Hydrogel achieved optimal MB removal efficiency (69.53%) at an initial MB concentration of 250 mg/L (1 mg/mL, pH not adjusted) over 24 h. Adsorption kinetics, isotherm, thermodynamic studies, and reusability were investigated. Experimental adsorption isotherm and kinetic data followed the Langmuir model and pseudo-second-order kinetics with a maximum adsorption capacity of 284.90 mg/g hydrogel at 293 K. Thermodynamic findings proved the spontaneity and endothermic behavior of the adsorption process. After 5 adsorption-desorption cycles, the adsorption capacity of the composite hydrogel decreased by only 7.51 mg/g compared to the initial adsorption capacity.Öğe Öğe Halkalı fosfazenlerin aminoliz ve alkoliz reaksiyonlarının incelenmesi(Çanakkale Onsekiz Mart Üniversitesi, 2010) Özay, Hava; Yıldız, MustafaBu çalışmada halkalı fosfazenler trimer ve tetramerin aminoliz ve alkoliz reaksiyonları incelendi. Aminoliz reaksiyonları için amino podandlar (3 ve 4) sentezlenerek, ticari aminlerde satın alınarak kullanıldı. Amino podandlar ile trimer ve tetramerin reaksiyonlarından spiro ve bino fosfazen bileşikleri (5, 6, 7 ve 8) elde edildi. Bileşik 6 ve 7'nin t-butilaminin aşırısı ile tepkimesinden gem-sübstitüe spiro ve bino fosfazen bileşikleri 9 ve 10 sentezlendi. Ticari diaminler ile trimerin reaksiyonundan bino bileşikleri 11, 12 ve 13, tetramerin reaksiyonundan ise bisiklo 14 bileşiği elde edildi. Trimerin hidroksialdehitler ile alkoliz reaksiyonları sonucu tamamen sübstitüe olmuş formil fosfazen bileşiği 15, tetrasübstitüe formil fosfazen bileşiği 16 ve monosübstitüe formil fosfazen bileşiği 17 sentezlendi. Bileşik 15 ile 16'nın aminlerin aşırısı ile reaksiyonundan fosfaza-Schiff bazı bileşikleri 18, 19, 20 ve 21 elde edildi. Elde edilen tüm fosfazen bileşiklerinin bakteri ve maya kültürlerine karşı antimikrobiyal aktiviteleri incelendi.Sentezlenen fosfazen bileşiklerinin yapıları, element analizi, UV-VIS, IR, 1H-NMR, 13C-NMR, 31P-NMR ve MS spektrumları verilerinden faydalanılarak aydınlatıldı. Ayrıca bileşik 5, 6, 9 ve 17'nin yapısı X-ışınları kristallografisi yöntemiyle incelendi.Öğe Highly efficient removal of methyl orange from aqueous media by amine functional cyclotriphosphazene submicrospheres as reusable column packing material(Elsevier B.V., 2021) Önder, Alper; Özay, HavaPolyphosphazenes have an important place in material science because they allow functional diversity to be realized easily. In this study, for the first time, synthesis of cyclomatrix-type poly-(cyclotriphosphazene-co-4-(aminomethyl)-1,8-octanediamine) (Phz-AO) particles including different surface features and dimensions have been reported using different stoichiometric ratios of hexachlorocyclotriphosphazene and 4-(aminomethyl)-1,8-octanediamine. The use of Phz-AO (1:2) submicroparticles with spherical form and average dimension of 647.82 ± 22.23 nm as an adsorbent was researched for methyl orange (MO) anionic azo dye. Submicrospheres had significant potential for adsorption of negative charged MO and maximum adsorption capacity of 1244.7 mg.g − 1. The submicrospheres displayed high adsorption potential at pH ≤6 conditions thanks to their surface amine groups. The maximum adsorption capacity in synthetic textile wastewater was 912.75 mg.g−1 as experimental. While the adsorption kinetics had the pseudo second order model, the most suitable model for adsorption was the Langmuir isotherm. The thermodynamic parameters for MO adsorption with submicrospheres were 10.02 ± 1.81 kj.mol−1 for ΔH°, 61.08 ± 5.74 j.mol−1.K−1 for ΔS° and ΔG° (kj.mol−1)<0. In light of all data obtained, the Phz-AO (1:2) submicrospheres which can be easily prepared with a single-step reaction are expected to be a remarkable member of the super adsorbent material family.Öğe Investigation of Drug Release Behavior of Cyclomatrix Polyphosphazene Microparticles Decorated with Gold and Silver Nanoparticles(John Wiley and Sons Inc, 2024) Dilek, Esra; Özay, HavaIn this study, p(CTP-co-MMCA) microparticles, a novel cyclomatrix polyphosphazene, were synthesized. Among the p(CTP-co-MMCA) polymeric structures, p(CTP-co-MMCA) (1 : 3) with a high surface amine group was found to be in the form of microparticles after detailed structural and morphological characterization. These microparticles were modified with Au0 and Ag0 nanoparticles using two different green reductants. The antimicrobial activities of p(CTP-co-MMCA) microparticles and their Au0 and Ag0 composites against P.Aeruginosa ATCC 27853, S.Aureus ATCC 6538 and C.Albicans were investigated. Metal composites were found to have better antimicrobial activity. Cyclomatrix p(CTP-co-MMCA) microparticles with antimicrobial properties and their Au0 and Ag0 composites were also used for the release of Ceftriaxone sodium and RNA. Cyclomatrix p(CTP-co-MMCA) microparticles and its Au0 and Ag0 composites retained 48.21±5.34 mg/g, 49.36±6.95 mg/g and 23.95±6.45 mg/g ceftriaxone sodium, respectively, while they retained 79.15±6.85 mg/g, 47.49±6.24 mg/g and 57.47±9.48 mg/g RNA, respectively. Release studies revealed that the presence of Au0 and Ag0 nanoparticles imparted a slower release behavior to p(CTP-co-MMCA) microparticles. The release studies revealed that the presence of Au0 and Ag0 nanoparticles imparted a slower release behavior to the p(CTP-co-MMCA) microparticles.Öğe Novel hydrogels based on crosslinked chitosan with formyl-phosphazene using Schiff-base reaction(Taylor & Francis Group, LLC, 2021) Özay, Hava; Ilgın, Pınar; Özay, ÖzgurIn this study, chitosan, an aminopolysaccharide, was reacted with phosphazene-derived crosslinker by Schiff-base reaction to yield crosslinked-chitosan hydrogel. Here, hexakis(4-formylphenoxy)cyclotriphosphazene was used as a novel crosslinker agent with six reactive functional groups allowing the formation of bridges between polymeric chains. Amoxicillin, known effective bacteriostatic treatment, was used as a model drug to test the drug-carrying capacity of the gel and the antibacterial activity. Further, the acid-catalyzed aqueous degradation behavior of hydrogels was assessed in vitro. In conclusion, it is predicted that this newly obtained biodegradable hydrogel may have the potential to be used as a promising drug-carrying material in biomedical application fields.Öğe Preparation of composite hydrogels containing fly ash as low-cost adsorbent material and its use in dye adsorption(Springer Science and Business Media Deutschland GmbH, 2022) Önder, Alper; Ilgın, Pınar; Özay, Hava; Özay, ÖzgürAbstract: Recycling industrial wastes is necessary for the economy and the environment. Additionally, it is important to develop high-efficiency adsorbents to prevent severe water pollution caused by wastewater containing dye agents. Here, poly(2-acrylamido-2-methylpropane sulfonic acid)-fly ash composite hydrogel was synthesized with a variety of fly ash proportions with the radical polymerization method. The synthesized composite hydrogel was used for adsorption of methylene blue and methyl orange dyes from water containing dye agents. A variety of parameters such as initial dye concentration, solution pH, anion effects, temperature, contact time and adsorbent amount were investigated for optimization of the adsorption process. The poly(2-acrylamido-2-methylpropane sulfonic acid)-fly ash composite hydrogel was determined to be an effective adsorbent to remove both the cationic dye methylene blue (1438.68 mg g−1) and the anionic dye methyl orange (646.54 mg g−1). Experimental adsorption data were assessed with a variety of isotherm and kinetic models. It was determined that the adsorption of both dye molecules abided by the pseudo-second-order kinetic model. The thermodynamic parameters were determined as ΔH° = − 15.77 ± 5.22 kJ mol−1, ΔS = − 45.05 ± 16.42 J mol−1 K−1 and ΔG° < 0 for MB, ΔH° = − 20.13 ± 4.83 kJ mol−1, ΔS = − 72.87 ± 15.20 J mol−1 K−1 and ΔG° > 0 for MO. In conclusion, a material was synthesized that can be used as a single adsorbent composite material for both anionic and cationic dyes. In addition to the perfect adsorption capacity of this material, it offers reusability and a broad area of application for a variety of dye agents.Öğe Synthesis and characterization of biodegradable and antioxidant phosphazene-tannic acid nanospheres and their utilization as drug carrier material(Elsevier Ltd, 2021) Önder, Alper; Özay, HavaIn this study, hexachlorocyclotriphosphazene (HCCP) and tannic acid (TA) were used at different stoichiometric ratios to synthesize cyclomatrix-type polymeric materials with different surface features and dimensions. Using different reactive ratios, the structure and surface functional groups of the synthesized polymeric particles were explained using Fourier-Transform Infrared Spectroscopic (FTIR), Scanning Electron Microscope (SEM), Energy-dispersive X-ray spectroscopy (EDX), X-ray Photoelectron Spectroscopy (XPS) and Thermogravimetric (TG) analysis techniques. With morphologically fully spherical structure and mean 234.82 ± 49.37 nm dimensions, Phz-TA (4:1) nanospheres were researched for in vitro biodegradability, antioxidant features, and usability as a drug release system. In vitro biodegradability of Phz-TA (4:1) nanospheres was investigated at pH = 7.0 and pH = 1.2. Determined to degrade in 8–10 h at these pH values, nanospheres were used for releasing of Rhodamine 6G as a model drug. Due to the rich phenolic structure of the contained tannic acid units, nanospheres were determined to simultaneously have antioxidant features. Thus, this study determined that Phz-TA nanospheres with in vitro biodegradability and antioxidant features are promising polymeric materials for use as a potential drug-carrier in the future.Öğe Synthesis and characterization of cyclomatrix polyphosphazenes framework nanospheres-supported Cu0 nanocatalyst and its use in hydrogen production from ethylenediamine bisborane(Elsevier Ltd, 2024) Önder, Alper; Özay, HavaIn this study, Cp-BAP3@Cu catalyst system containing Cu0 nanoparticles with an average size of 4.23 ± 1.97 nm was prepared by using Cp-BAP nanospheres containing cyclotriphosphazene with an average size of 306.31 ± 61.54 nm as support material. Characterizations of the synthesized polymeric materials and catalyst system were carried out by various analysis techniques. The Cp-BAP3@Cu catalyst system was used for the catalytic hydrolysis reaction of ethylenediamine bisborane (EDAB). For the hydrolysis reaction of EDAB, Cp-BAP3@Cu had a turnover frequency of 1539 mol H2/mol Cu0. h at 30 °C. The activation parameters for the hydrolysis reaction were Ea = 47.36 ± 0.52 kJ/mol, ΔH0 = 44.73 ± 0.52 kJ/mol and ΔS0 = −153.81 ± 6.14 J/mol.K. The Cp-BAP3@Cu catalyst system has an important catalytic activity in the formation of H2 from the hydrolysis of EDAB.Öğe Synthesis of p(HEMA-co-AETAC) nanocomposite hydrogel with vinyl-function montmorillonite nanoparticles and effective removal of methyl orange from aqueous solution(Taylor and Francis Ltd., 2023) Önder, Alper; Ilgın, Pınar; Özay, Hava; Özay, ÖzgürIt has become crucial to develop new adsorbents to remove toxic dye wastes from wastewater to protect our existing aquatic ecosystem. Here, to remove methyl orange azo dye from aqueous solutions, a new p(HEMA-co-AETAC)/VMt nanocomposite hydrogel was prepared by using 2-hydroxyethyl methacrylate and [2-(acryloyloxy)ethyl]trimethylammonium chloride monomers using vinyl-based montmorillonite crosslinker. Obtained new types of crosslinker and nanocomposite hydrogels have been characterized by various analysis methods. In addition, the effects of crosslinker amount, monomer amount and pH on the swelling behavior of nanocomposite hydrogel were investigated. The effects of essential parameters such as contact time, initial dye concentration, pH effect of the solution, adsorbent amount, and temperature on adsorption were evaluated. It was determined that there was no significant change in the adsorption ability of the nanocomposite hydrogel in the pH range of 3–10. Experimental results showed that the Langmuir isotherm model fit better, and the calculated maximum adsorption capacity was 961.54 mg/g. In addition, it was determined that vinyl-based montmorillonite used as a crosslinker supported MO adsorption. p(HEMA-co-AETAC)/VMt nanocomposite hydrogel may be a new type of adsorbent to remove toxic synthetic dye residues from aqueous media.Öğe Synthesis, characterization, and in vitro drug release properties of AuNPs/p(AETAC-co-VI)/Q nanocomposite hydrogels(Springer Science and Business Media Deutschland GmbH, 2021) Durmuş, Seçil; Yılmaz, Betül; Kıvanç, Mehmet Rıza; Önder, Alper; Ilgın, Pınar; Özay, Hava; Özay, ÖzgürIn this study, the cationic monomer [2-(acryloyloxy)ethyl]trimethylammonium chloride solution (AETAC) and vinyl imidazole (VI) were used with the free radical polymerization technique, which is a simple and rapid synthesis method, to synthesize p(AETAC-co-VI) hydrogels. To increase the density of cationic charge on the hydrogel, it underwent the protonation process with HCl. The obtained p(AETAC-co-VI)/Q hydrogel was modified with Au nanoparticles to increase bactericidal effect to obtain the AuNPs/p(AETAC-co-VI)/Q nanocomposite hydrogel. The morphology and chemical structure of the hydrogels were characterized with SEM and FTIR. Additionally, the swelling capabilities were tested in different pH media. XRD and TEM confirmed the formation of the nanocomposite hydrogel. The antibacterial activity of the hydrogels was tested against E. coli and S. aureus, and controlled release implementations were completed with sodium diclofenac (NaDc) drug. The NaDc drug release profiles of the hydrogels were researched using the Korsmeyer–Peppas model at 37 °C in different simulated buffer (pH 6.0, 7.2, and 8.0) solutions. It was found that both the hydrogel and nanocomposite hydrogel followed non-Fickian diffusion mechanisms as free release mechanism. Here, the maximum drug release efficacy was found to be 97%, and drug release was more rapid in basic media when release media were compared. The AuNPs/p(AETAC-co-VI)/Q nanocomposite hydrogels produced in this study with advanced antibacterial features were suitable for recommendation as good carriers for in vitro release of NaDc drugs in areas like the biomedical and pharmaceutical industries.Öğe Synthesis, spectroscopic studies and structure of 2-[(Benzo[d]thiazol-2- ylamino)methyl]phenol(Springer New York LLC, 2010) Yıldız, Mustafa; Özay, Hava; Ünver, Hüseyin; İskeleli, Nazan Ocak; Mehmet Zengin, D.; Durlu, Tahsin NuriSchiff base (E)-2-[(benzo[d]thiazol-2-ylimino)methyl]phenol (1) has been synthesized from the reaction of 2-hydroxy-benzaldehyde with 2-aminobenzothiazole. The 2-[(benzo[d]thiazol-2-ylamino)methyl]phenol (2) was prepared reduction of the Schiff base 1 with sodium borohydride. The compounds 1 and 2 have been characterized by elemental analysis, FT-IR, 1 H-NMR, 13 C-NMR and UV-visible spectroscopic techniques. The structure of the compound 2 has also been examined crystallographically. The compound 2 crystallizes in the monoclinic space group P2/c. The unit cell parameters were found as a = 10.017(1), b = 11.725(1), c = 10.341(1) Å, V = 1208.1(1) Å 3 , D x = 1.409 g cm -3 and Z = 4. The crystal structure was solved by direct methods and refined by the full-matrix least squares method and found as R 1 = 0.0308 and wR 2 = 0.0818 for 2032 for the observed reflections [I > 2?(I)]. Graphical Abstract: Crystal and molecular structure of the compound 2-[(benzo[d]thiazol-2- ylamino)methyl]phenol have been studied in order to reveal the presence of either the enol-imine or keto-amine forms related with hydrogen bonding by using FT-IR, 1 H-NMR, 13 C-NMR, UV-visible spectroscopic and X-ray crystallographic techniques.[Figure not available: see fulltext.] © 2010 Springer Science+Business Media, LLC.
