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Öğe A new candidate for wound dressing materials: s-IPN hydrogel-based highly elastic and pH-sensitive drug delivery system containing pectin and vinyl phosphonic acid(Pergamon-Elsevier Science Ltd, 2024) Seref, Elif; Ilgin, Pinar; Özay, Özgür; Ozay, HavaIn this study, we developed pH-sensitive semi-interpenetrating network (s-IPN) hydrogels, composed of pectin, 2hydroxyethyl methacrylate (HEMA), and vinyl phosphonic acid (VPA) using N,N'-methylene bis(acrylamide) (MBA) as a cross-linker with the free-radical polymerization method. The formation of s-IPNs was confirmed by FTIR studies. SEM images showed the addition of VPA to the polymeric matrix of s-IPN hydrogels formed additional microporous structures within the hydrogel network. The s-IPN hydrogel had perfect mechanical features like stretchability, compressibility and elasticity. Additionally, the swelling behavior of s-IPN hydrogels in deionized water and solutions with diverse pH was assessed. To research use as a controlled drug delivery material, the hydrogel was loaded with cimetidine and trimethoprim. At pH 7.2, the in vitro drug release profile was observed and nearly 60 % of the drugs were released from s-IPN hydrogel within 10 h. Additionally, the most appropriate kinetic release model was Higuchi, followed by Korsmeyer-Peppas. Finally, silver sulfadiazine (SSD) was added to s-IPN hydrogel for use as a smart wound dressing material. Antimicrobial analysis of the SSDloaded s-IPN hydrogel found it had antimicrobial features, inducing 15, 17 and 23 mm inhibition zones against Staphylococcus aureus (gram-positive), Escherichia coli (gram -negative) and Candida albicans (fungus) microorganisms, respectively. In light of the obtained results, based on being easily shapable with appropriate mechanical and physical features, pectin/p(HEMA-co-VPA) and pectin/p(HEMA-co-VPA)@SSD s-IPN hydrogels are potential candidates for use as controlled drug delivery and wound dressing materials in the biomedical field.Öğe A new dual stimuli responsive hydrogel: Modeling approaches for the prediction of drug loading and release profile(Pergamon-Elsevier Science Ltd, 2019) Ilgin, Pinar; Ozay, Hava; Özay, ÖzgürIn this study, N-tert-butylmaleimic acid was designed for the first time and synthesized by reaction of maleic anhydride with tert-butylamine and evaluated as a new functional monomer for preparation of new pH-responsive hydrogels. Its structure was verified with FTIR, H-1 and C-13 NMR. A new pH- and temperature-responsive hydrogel p(TBMAC-co-NIPAM), based on TBMAC and NIPAM, was successfully prepared via free-radical copolymerization technique in an aqueous solution. The chemical and structural properties of the hydrogels were identified by FTIR and SEM. The swelling properties of these hydrogels were systematically investigated according to various parameters such as time, temperature, pH and salt effects, and the results show that they are strongly influenced by the content of TBMAC and exhibit strong pH, temperature and salinity sensitivity. In addition, swelling kinetics and water diffusion mechanisms in hydrogels were discussed. In addition, in vitro drug release studies were performed in simulated gastric, isotonic serum and intestinal fluid at two different temperatures (23 and 37 degrees C) by taking R6G as a model drug. Drug loading results were investigated with various isotherm models such as Langmuir, Freundlich, Temkin and Dubinin-Radushkevich. Various kinetic models such as zero-order, first-order, Higuchi model and Korsmeyer-Peppas models were applied to determine the drug release mechanism. The results indicated that drug release involves non-Fickian transport mechanism. These results suggest that this new pH - and thermo-responsive hydrogel may be used to improve sustained release of drugs.Öğe A novel hydrogel containing thioether group as selective support material for preparation of gold nanoparticles: Synthesis and catalytic applications(Elsevier Science Bv, 2019) Ilgin, Pinar; Özay, Özgür; Ozay, HavaIn this study, firstly N-metacrylamido thiomorpholine containing thioether group was synthesized as monomer. Then, p(AAm-co-MTM) hydrogels were prepared from the redox polymerization of acrylamide and N-metacrylamido thiomorpholine as a selective support material. p(AAm-co-MTM) hydrogel-gold nanoparticles were obtained as a result of the reduction of the selectively absorbed gold(III) ions by the hydrogel network using NaBH 4 as reducing agent. All materials were characterized using techniques such as SEM, EDX, TEM and XRD analysis. It was determined that p(AAm-co-MTM)-Au composite material has high catalytic activity for the reduction of 4-nitrophenol. The activation parameters of the reduction reaction of 4-nitrophenol using NaBH4 in the presence of p(AAm-co-MTM)-Au catalyst were calculated as E-a = 38.80 kJ/mol, Delta H-# = 36.16 kJ/mol and Delta S-# = - 161.37 J/mol K.Öğe Adsorption of Malachite Green from Aqueous Solution Using Hydroxyethyl Starch Hydrogel Improved by Graphene Oxide(Springer, 2022) Onder, Alper; Kivanc, Mehmet Riza; Durmus, Secil; Ilgin, Pinar; Ozay, Hava; Özay, ÖzgürThis study is the first report of the preparation of hydroxyethyl starch (HES) hydrogels rapidly crosslinked with divinyl sulfone in a single step and single pot. To develop the physical and chemical features of hydrogels, Graphene oxide (GO) nanoparticles were combined with the crosslinked HES. In addition to swelling studies, structural characterization of the samples was conducted with a scanning electron microscope (SEM) and transmission electron microscope (TEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometry (XRD), Brunauer-Emmett-Teller (BET) analysis and thermogravimetric analysis (TGA). For the removal of malachite green model dye by GO-HES, the effects of GO content, solution concentration, temperature, contact duration, dosage and pH on varying adsorption features were researched. Additionally, adsorption isotherms, kinetic and thermodynamic systematics were analyzed. The maximum adsorption capacity of GO-HES composite hydrogel was found to be 89.3 mg/g for Langmuir isotherm. The possible adsorption mechanism of the composite hydrogels for malachite green dye involved electrostatic, hydrogen bonding, and pi-pi interactions. In addition to reasonable cost and simple synthesis method, the prepared composite materials have potential use in wastewater treatment as adsorbents for the removal of dye from aqueous solutions due to efficient adsorption capacity.Öğe An innovative approach to use zeolite as crosslinker for synthesis of p(HEMA-co-NIPAM) hydrogel(Springer Wien, 2022) Durmus, Secil; Yilmaz, Betul; Onder, Alper; Ilgin, Pinar; Ozay, Hava; Özay, ÖzgürThis study introduced a modified method to synthesize organic-inorganic hybrid crosslinker based on zeolite. First, zeolite nanoparticles were modified with 3-(aminopropyl)trimethoxysilane. Then, the amine-functionalized zeolite has been reacted with the glycidyl methacrylate via an epoxide ring-opening mechanism. The vinyl-functionalized zeolite was applied as a crosslinking agent to form hydrogel network. A novel temperature-sensitive nanocomposite hydrogel was prepared by crosslinking N-isopropylacrylamide as a comonomer and 2-hydroxyethyl methacrylate as a monomer with free-radical polymerization. Results showed that p(2-hydroxyethyl methacrylate-co-N-isopropylacrylamide)/vinyl-functionalized zeolite nanocomposite hydrogel has a chemically crosslinked and porous network structure. The content of crosslinker and monomers had obvious effects on the swelling ratio of the nanocomposite hydrogel. The temperature and salt-sensitive behavior of the hydrogels are also discussed. We offer a multifunctional crosslinker for preparing sensitive materials that can serve biomedical or environmental applications.Öğe Colloidal drug carries from (sub)micron hyaluronic acid hydrogel particles with tunable properties for biomedical applications(Elsevier Sci Ltd, 2010) Ilgin, Pinar; Avci, Gulden; Sılan, Coşkun; Ekici, Sema; Aktas, Nahit; Ayyala, Ramesh S.; John, Vijay T.Hyaluronic acid (HA) hydrogel particles were synthesized in a single step employing water-in-oil microemulsion system. The HA particles were formed in the micro-environments of aqueous HA solution in oil by chemical crosslinking with divinyl sulfone (DVS). To produce magnetic field responsive HA-composite particles, iron magnetic nanoparticles were introduced into microemulsion system during synthesis to obtain HA-magnetic composites. For this purpose, iron nanoparticles were separately synthesized and mixed with linear HA followed by chemical crosslinking of linear HA with DVS in the micro-environments to envelope magnetic metal nanoparticles in the emulsion system. Scanning electron microscopy (SEM), dynamic light scattering (DLS) studies, and zeta potentials measurement were performed for particle size, charge and morphological characterization. Additionally. HA particles were chemically modified to induce desired functional groups on the particle surface and utilized for potential drug delivery vehicles. Trimethoprim (TMP) a bacteriostatic antibiotic drug were used as a model drug for the release studies in phosphate buffer solution (PBS) at pH 7.4 from bare HA, magnetic HA-composite and modified HA hydrogel particles. (C) 2010 Elsevier Ltd. All rights reserved.Öğe Dual use of colorimetric sensor and selective copper removal from aqueous media with novel p(HEMA-co-TACYC) hydrogels: Cyclen derivative as both monomer and crosslinker(Elsevier, 2020) Ozay, Hava; Gungor, Zeynep; Yilmaz, Betul; Ilgin, Pinar; Özay, ÖzgürWithin the scope of this study, p(2-hydroxyethyl methacrylate-co-tetraacrylic cyclen) (p(HEMA-co-TACYC)) hydrogels were synthesized for the first time in the literature using a tetraacrylic cyclen (TACYC) as both functional monomer and crosslinker. The hydrogels designed especially for Cu2+ ions showed colorimetric sensor behavior selective for Cu2+ ions in all aqueous media (deionized, tap, river and sea water) and in metal ion mixtures. The p(HEMA-co-TACYC) hydrogels forming a stable complex with Cu2+ ions simultaneously showed properties of being a good adsorbent material. The hydrogels have reuse capacity as both sensor and adsorbent material. Changing the amount of TACYC in the hydrogel structure changes the maximum adsorption capacity for Cu2+ ions. The Langmuir and Freundlich adsorption constants for Cu2+ ion adsorption of the hydrogels, acting as selective adsorbent in all aqueous media and metal ion mixtures, were determined.Öğe Eco-Friendly Preparation of Pectin-Stabilized Ruthenium Catalyst for Hydrogen Generation from Sodium Borohydride Hydrolysis(Wiley-V C H Verlag Gmbh, 2024) Ilgin, Pinar; Ozay, Hava; Özay, ÖzgürIn this study, we report that pectin-supported ruthenium nanoparticles (pectin@Ru0) can be easily prepared at room temperature by a simple and effective method and that they exhibit outstanding catalytic activity in the hydrolysis of sodium borohydride (NaBH4). The structure, oxidation state, morphology, and thermal studies were analyzed using XRD, XPS, SEM, TEM and TGA analysis. The kinetic performance of pectin@Ru0 biocatalyst was evaluated depending on ruthenium loading, NaBH4 concentration, NaOH concentration, temperature, reusability and storage. The pectin@Ru0 biocatalyst containing 2 wt.% Ru0 metal catalyzed the hydrolysis of 50 mM NaBH4+1 wt.% NaOH with 100 % yield. The activation energy (Ea) and the TOF values of the reaction was estimated as 54.7 kJ mol-1 and 53.1 mol H2 (mol Ru0 min) -1 at 30 degrees C and this is consistent with other previously reported catalysts, making it a remarkable result in comparison. Reusability and catalytic life studies reported that pectin@Ru0 biocatalyst is also highly active and relatively long-lived catalyst in the hydrolysis of NaBH4 in a slightly basic solution. Pectin@Ru0 biocatalyst was successfully synthesized and tested for H2 production in catalytic hydrolysis of NaBH4. HGR and TOF were calculated as 12848 mL/(min.g) and 53.1 mol H2/(mol Ru0 min) at 30 degrees C. Ea was calculated as 54.7 kJ/mol. The reusability of this new catalyst was tested 10 times with 81.5 % stability and 100 % conversion. Storage of biocatalyst can retain 87 % of initial HGR after 30 days. imageÖğe Graphene nanoplate incorporated Gelatin/poly(2-(Acryloyloxy)ethyl trimethylammonium chloride) composites hydrogel for highly effective removal of Alizarin Red S from aqueous solution(Springer, 2022) Ozsoy, Fatma; Ozdilek, Batuhan; Onder, Alper; Ilgin, Pinar; Ozay, Hava; Özay, ÖzgürThe increasing water pollution day by day has increased the importance of developing new adsorbent materials. In this study, composite hydrogel containing gelatin, [2-(Acryloyloxy)ethyl] trimethylammonium chloride (AETAC) and Graphene Nanoplate (GNPt) was developed as an adsorbent for the removal of dyes from wastewater. Fourier Transform Infrared Spectrophotometer, Scanning Electron Microscope, X-Ray Diffractometer results confirmed the crosslinked polymer structure of Gelatin/p(AETAC)/GNPt composite hydrogel (Gel 5). In addition, equilibrium swelling ratio, which is a parameter affecting the adsorption behavior, was 48.22 g(water) /g(gel). The adsorption behavior of Alizarin Red S anionic dyestuff on composite hydrogel from aqueous solutions was investigated under various experimental conditions such as initial dye concentration of solution, amount of adsorbent, contact time, pH of solution, temperature of solution. ARS dye adsorption on composite hydrogel is consistent with Pseudo-Second-Order kinetic model and Langmuir isotherm with max adsorption capacity of 649.35 mg/g. The composite hydrogel with high mechanical strength has high dye removal ability in the ranging pH from 4 to 8. Therefore, it can be said that Gelatin/p(AETAC)/GNPt composite hydrogel has a substantial potential for the removal of anionic dyes from wastewater in a wide pH range.Öğe Green synthesis of multifunctional responsive hydrogel embedded with silver, based on xanthan gum, N-isopropylacrylamide, vinyl imidazole, and Luffa cylindrica for wound healing(Taylor & Francis Inc, 2024) Atli, Ilknur; Ilgin, Pinar; Özay, ÖzgürIn this study, a pH- and temperature-responsive smart hydrogel was developed by utilizing Xanthan Gum (XG), N-Isopropylacrylamide (NIPAM), Vinyl Imidazole (VI), and Luffa cylindrical (LC). Semi-interpenetrating polymer networks (semi-IPNs) were created using free radical polymerization with N,N '-methylenebisacrylamide (MBA) as the cross-linker and ammonium persulfate (APS) as the initiator. Silver nanoparticles (AgNPs) were synthesized within semi-IPN hydrogel network structures to impart antibacterial properties. Malva sylvestris (MS) aqueous leaf extract was used as a reducing and stabilizing agent for the green synthesis of the AgNPs. The semi-IPN hydrogels exhibited pH- and temperature-responsive swelling behavior, which also enabled the controlled release of the drug. After 11 h, the cumulative release reached approximately 73% at pH 7.2 and 87% at pH 8.3. Additionally, the sustained release mechanism of the Trimethoprim drug was described using the Korsmeyer-Peppas model and was governed by Fickian diffusion. The drug-loaded semi-IPN@Ag nanocomposite hydrogel has demonstrated effective antibacterial activity against various Gram-negative and Gram-positive bacteria, indicating its promising potential as a wound dressing material for reducing infection risk.Öğe High removal of methylene blue dye from aqueous solution by using a novel pectin-based hydrogel(Taylor & Francis Ltd, 2022) Ilgin, PinarIn this study, pectin/poly(methacrylic acid-co-2-acrylamido-2-methylpropane sulphonic acid) (pec/poly(MA-co-AMPS)) hydrogel was synthesised with free-radical polymerisation. The effect of the compound proportions within the pectin-based hydrogels on swelling behaviour was investigated. Confirmation of the chemical structure of the prepared hydrogel used FT-IR spectroscopy. Surface morphology assessment was performed with SEM. Cationic methylene blue (MB) dye was chosen to investigate adsorption studies using these anionic-character hydrogels. The adsorption conditions affecting performance of initial dye concentration, solution pH, adsorbent mass, contact duration and temperature were systematically investigated. Kinetics of MB adsorption abided by a pseudo-second-order model. The adsorption isotherm for hydrogels was best described by the Langmuir isotherm model and it was found to have maximum MB adsorption capacity of 448.4 mg/g at 60 min duration. Thermodynamic investigation of the adsorption process linked to temperature found the adsorption process had random, spontaneous and endothermic favourability. In conclusion, pec/poly(MA-co-AMPS) hydrogel is accepted as a promising candidate to remove MB or cationic dyes with similar features from aqueous solutions.Öğe Highly effective palladium nanocatalyst supported in polymeric networks for the catalytic hydrogen generation from borane-morpholine complex(Wiley-V C H Verlag Gmbh, 2022) Ozay, Hava; Tercan, Melek; Özay, Özgür; Ilgin, PinarThis study describes the synthesis of Pd-0 nanoparticles supported in hydrogel networks (SPVI@Pd) and their catalytic activity for the borane-morpholine complex (MB) hydrolysis reaction. In this respect, while our study is one of the limited number of studies reported for the catalytic hydrolysis of MB, it is the first study in which Pd-0 nanoparticles supported in hydrogel networks were used in the catalytic hydrolysis of MB. The synthesized Pd-0 nanoparticles were characterized using structural and morphological characterization techniques and as a result of these analyses, the sizes of Pd-0 nanoparticles were determined average as 7.01 +/- 1.90 nm. The E-a value and the turnover frequency (TOF) value at 303 K for the SPVI@Pd-3.0 catalyzed MB hydrolysis reaction were determined as 49.46 kJ/mol and 187.74 mol(H2)center dot mol(pd)(-1).h(-1). It was also observed that the SPVI@Pd-3.0 catalyst had good catalytic activity even after eight cycles.Öğe Hydrogen production via copper nanocatalysts stabilized by cyclen derivative hydrogel networks from the hydrolysis of ammonia borane and ethylenediamine bisborane(Pergamon-Elsevier Science Ltd, 2020) Ozay, Hava; Ilgin, Pinar; Özay, ÖzgürIn this study, p(AAm-co-TACYC) hydrogels were synthesized using TACYC crosslinker. The p(AAm-co-TACYC) hydrogel was used for preparation of Cu(0) nanoparticles as support material. The p(AAm-co-TACYC)@Cu was prepared by chemical reduction of Cu2+ ions in the p(AAm-co-TACYC) networks and was structurally characterized in detail. Later the catalytic activity of p(AAm-co-TACYC)@Cu was investigated for hydrogen production from AB and EDAB hydrolysis. Detailed kinetic studies were performed for both hydrogen storage materials. The p(AAm-co-TACYC)@Cu was a more active catalyst for the EDAB hydrolysis reaction. The E-a values of p(AAm-co-TACYC)@Cu for the AB and EDAB hydrolysis reactions were determined as 68.36 kJ mol(-1) and 39.07 kJ mol(-1), respectively. In addition to the perfect catalytic activity of p(AAm-co-TACYC)@Cu, it had good reusability. After ten consecutive uses for AB and EDAB hydrolysis, the p(AAm-co-TACYC)@Cu still had 88% and 85% of initial activity, respectively. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.Öğe Novel stimuli-responsive hydrogels derived from morpholine: synthesis, characterization and absorption uptake of textile azo dye(Springer, 2017) Ilgin, Pinar; Özay, ÖzgürA new cationic monomer methacrylamido-4-(2-aminoethyl) morpholine, (MAEM) derived from morpholine was synthesized in a single step and characterized by FTIR, H-1 and C-13 NMR analyses. Through free radical aqueous polymerization, novel copolymeric hydrogels have been prepared successfully using methacrylamido-4-(2-aminoethyl) morpholine and acrylamide (Aam) as monomers. Later on SEM, FTIR, elemental analysis and TG instruments were used to characterize the obtained poly(acrylamide-co-methacrylamido-4-(2-aminoethyl) morpholine), poly(Aam-c-MAEM), hydrogels. Poly(Aam-c-MAEM) hydrogels were tested for swelling, diffusion and uptake of reactive orange, RO, anionic dye. In this regard, various adsorption kinetics and isotherm models as well as operation parameters were systematically examined and discussed in detail in relation to adsorption uptake such as pH of media, comonomer composition, adsorbent dosage, temperature, initial dye concentration and contact time. The description of adsorption process of RO on hydrogels was consistent with the pseudo-second-order model followed by Elovich and pseudo-first-order. The best fitting adsorption model was selected on the basis of R-2, in the order of: Temkin > D-R > Langmuir > Freundlich isotherm. The results obtained in this study demonstrate that poly(Aam-c-MAEM) hydrogels provide an excellent advantage for application of this hydrogel system in the removal of anionic textile dyes from wastewater.Öğe Pd nanoreactors with excellent catalytic activity supported in p(SPA) hydrogel networks for hydrogen production from ethylenediamine bisborane(Pergamon-Elsevier Science Ltd, 2020) Ozay, Hava; Ilgin, Pinar; Sezgintürk, Mustafa Kemal; Özay, ÖzgürIn this study we synthesized Pd(0) nanoparticles with nearly 20 nm size using p(3-Sulfopropyl acrylate) (p(SPA)) hydrogel as support material. Pd@p(SPA) containing Pd (0) nanoparticles with nearly homogeneous distribution was characterized structurally with TEM, XRD, XPS and elemental mapping. The Pd@p(SPA) was used for the catalytic hydrolysis reaction of ethylenediamine bisborane (EDAB). A series of reactions were completed by changing parameters like the catalyst amount, EDAB concentration and temperature. The Pd@p(SPA) was determined to have turnover frequency (TOF) value of 354 mol H-2.molPd(0)(-1).h(-1) at 30 degrees C for the hydrolysis reaction of EDAB. The activation parameters for the reaction were E-a = 67.79 kJmo1(-1), Delta H-# = 65.15 kJmol(-1) and Delta S-# = -103.26 Jmol(-1) K-1. Pd@p(SPA) also had excellent reusability for the hydrolysis of EDAB. Even after ten reaction cycles, Pd@p(SPA) had 87% catalytic activity. At the same time after four months of storage in an aqueous medium, Pd@p(SPA) still had 100% catalytic activity. (C) 2020 Elsevier Ltd. All rights reserved.Öğe Preparation of antioxidant-biodegradable poly(acrylic acid-co-2-hydroxyethyl methacrylate) hydrogel using rutin as a crosslinker: Drug release and anticancer activity(Elsevier, 2023) Onder, Ferah Comert; Onder, Alper; Ilgin, Pinar; Ozay, Hava; Özay, ÖzgürIt is important to develop drug-release systems that reduce the side effects of chemotherapy drugs, can regulate drug release, and can be designed for a target to keep the quality of life of cancer patients high. In this study, a polyphenol compound rutin was used as a natural crosslinker to prepare poly(acrylic acid-co-2-hydroxyethyl methacrylate)/rutin (RTN hydrogel) as a drug carrier. The swelling behavior, thermal stability, in vitro biode-gradability, and antioxidant activity of this hydrogel were determined. The prepared hydrogel had in vitro biodegradability and antioxidant properties. The maximum doxorubicin (DOX) amount adsorbed by the RTN hydrogel was 32.96 & PLUSMN; 1.83 mg/g. The DOX-loaded RTN hydrogel displayed drug release behavior in normal and cancer cell media. At the same time, the effect of the DOX-loaded hydrogel on triple negative breast cancer (TNBC) cell lines was investigated. Our results show that the RTN hydrogel, prepared using the natural product of rutin as a crosslinker with in vitro biodegradability and antioxidant properties, offers great promise as a high-impact carrier in the drug distribution system.Öğe Rapid preparation of Ru(0) nanoparticles stabilized with water-soluble biopolymer for hydrogen production from ammonia borane: Development of battery-like hydrolysis media(Pergamon-Elsevier Science Ltd, 2023) Seref, Elif; Tercan, Melek; Ozay, Hava; Ilgin, Pinar; Özay, ÖzgürThe biohybrid Na-Alg@Ru catalyst was prepared as a result of stabilizing Ru(0) nano particles with biopolymer chains of sodium alginate. The in-situ prepared Ru(0) nano particles had an average particle size of 1.023 & PLUSMN; 0.097 nm. The monodisperse Ru(0) nanoparticles prepared with a very practical, inexpensive and rapid method were used as a catalyst in hydrogen production by the hydrolysis reaction of ammonia borane (AB). The Na-Alg@Ru catalyst containing 3 mg Ru(0) metal catalyzed the hydrolysis of 50 mM AB with 100% yield, and the activation energy (Ea) of the reaction was estimated as 61.05 kJ mol-1. In addition, the Na-Alg@Ru nanoparticles were prepared with acrylamide as p(AAm)/NaAlg@Ru hydrogel films suitable for use in hydrogen production in fuel cells, which represents a battery-like environment, and used for hydrogen production from AB. Thus, it was shown that the catalysts prepared in a few nm size could easily be used in battery-like environments.& COPY; 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.Öğe Removal of anionic dyes from aqueous media by using a novel high positively charged hydrogel with high capacity(Taylor & Francis Inc, 2022) Kivanc, Mehmet Riza; Özay, Özgür; Ozay, Hava; Ilgin, PinarPoly((methacryloylamino)propyl trimethylammonium chloride-co-vinylimidazole) (p(MAPTAC-co-VI)) hydrogels were synthesized through free radical polymerization of 3-(methacryloylamino)propyl trimethylammonium chloride (MAPTAC) and 1-vinylimidazole (VI) in aqueous solutions with ammonium persulfate (APS) used as initiator and N,N '-methylenebis(acrylamide) (MBA) as the crosslinking agent. By modifying with HCl, the positive charge density on the hydrogel network structure was increased and quaternized hydrogels (p(MAPTAC-co-VI)-q) were obtained. Traditional swelling and spectrophotometric characterization techniques were used to gain a better understanding of the performance of cationic hydrogels for the removal of anionic dyes. FTIR, SEM, and EDX confirmed the structure of the hydrogel before and after the adsorption process. Later, dye adsorption performance of these p(MAPTAC-co-VI)-q hydrogels was investigated under different adsorption conditions, including initial concentration, temperature, pH values of dye solutions, and adsorption contact time, adsorbent dosage and in real water samples. Various isotherm and kinetic models of dye adsorption by the hydrogel were also studied and the experimental adsorption followed a pseudo-second order model and fitted the Langmuir isotherm well. Thanks to the effective use of existing adsorption sites, high adsorption capacity was achieved for eriochrome black T (EBT) and methyl orange (MO) dyes. The values of q(max) are as follows: 1818.2 mg/g and 1449.3 mg/g, respectively. Thermodynamic parameters indicate that the process was spontaneous and endothermic. P(MAPTAC-co-VI)-q hydrogels can be used as a potential adsorbent for removal of anionic dye molecules, one of the industrial pollutants, from wastewater.Öğe Removal of dye from aqueous medium with pH-sensitive poly [(2-(acryloyloxy)ethyl]trimethylammonium chloride-co-1-vinyl-2-pyrrolidone] cationic hydrogel(Elsevier Sci Ltd, 2020) Onder, Alper; Ilgin, Pinar; Ozay, Hava; Özay, ÖzgürIn this study, p([2-(acryloyloxy)ethyl]trimethylammonium chloride-co-1-vinyl-2-pyrrolidinone) (p(AETAC-co-NVP) hydrogels containing positive charge in the structure were synthesized for the removal of anionic dyes from the aqueous media. The swelling behaviors affecting the adsorption properties of hydrogels structurally characterized by FTIR, SEM and EDX/mapping analysis were investigated. The effects of pH, dye concentration, adsorbent amount, dissolved anions and temperature on the adsorption of methyl orange (MO) and alizarin red S(AR) from aqueous media using p(AETAC-co-NVP) hydrogels were investigated. Using data obtained in adsorption studies, the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherms and pseudo-first order (PFO), pseudo-second order (PSO), intra-particular diffusion, and Elovich kinetic model analyses were performed. The results showed that the p(AETAC-co-NVP) hydrogel was a good adsorbent for MO and AR anionic dyes and the adsorption process for both dyes complied with the Freundlich isotherm and PSO kinetic model. This situation indicates that the dominant mechanism for the adsorption of MO and AR dyes by the p(AETAC-co-NVP) hydrogel is strong electrostatic interactions and occurs as multilayered adsorption, not only on a planar region. Additionally, to the maximum adsorption values using p(AETAC-co-NVP) hydrogel for MO and AR dyes were reached at pH values of 7.0 and 5.0, respectively. According to all these findings, it can be said that the p (AETAC-co-NVP) hydrogel containing positivelly charged groups is a super adsorbent for adsorption of anionic dyes.Öğe Ruthenium nanoparticles supported in the network of HES-p(AMPS) IPN hydrogel as efficient catalyst for hydrogen production from the hydrolysis of ethylenediamine bisborane(Pergamon-Elsevier Science Ltd, 2020) Ozay, Hava; Ilgin, Pinar; Sezgintürk, Mustafa Kemal; Özay, ÖzgürIn this study, Ru(0) nanoparticles supported in 2-hydroxyethyl starch-p-(2-Acrylamido-2-methyl-1-propanesulfonic acid) interpenetrating polymeric network (HES-p(AMPS) IPN) were synthesized as hydrogel networks containing hydroxyethyl starch, which is a natural polymer with oxygen donor atoms. The structure and morphology of the prepared HES-p(AMPS) IPN hydrogel and Ru@HES-p(AMPS) IPN catalyst were characterized using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), X-ray diffraction (XRD), and transmission electron microscope (TEM). Ru@HES-p(AMPS) IPN was used as catalyst for hydrogen production from the hydrolysis of ethylenediamine bisborane (EDAB). The activation parameters for the hydrolysis reaction of EDAB catalyzed by Ru@HES-p(AMPS) IPN were calculated as E-a = 38.92 kJ mo1(-1) , Delta H-# = 36.28 kJ mol(-1) , and Delta S-# = -111.85 J mol(-1) K-1 , respectively. The TOF for the Ru@HES-p(AMPS) IPN catalyst was 2.253 mol H-2 (mol Ru(0) min)(-1 ). It was determined that Ru@HES-p(AMPS) IPN, a reusable Hydrolysis catalyst, still had 81.5% catalytic activity after the 5th use. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
