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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 COLL 246-Hyaluronic acid hydrogel particles with micron and nano dimensions and their applications in drug delivery(Amer Chemical Soc, 2009) Ilgin, Pinar; Ozay, Hava; Aktas, Nahit; John, Vijay T.; Blake, Diane A.; Ayyala, Ramesh S.; Şahiner, Nurettin[Anstract Not Available]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 Hyaluronic acid hydrogel particles with tunable charges as potential drug delivery devices(Elsevier Sci Ltd, 2011) Ekici, Sema; Ilgin, Pinar; Butun, Sultan; Şahiner, NurettinWe report the synthesis of hyaluronic acid (HA) particles with positive and negative charges on their surfaces. HA-based particles were prepared using an aqueous solution of linear HA in a sodium bis(2-ethylhexyl) sulfosuccinate (AOT)-isooctane microemulsion system. The prepared HA particles were post modified, i.e., oxidized to aldehyde (HA-O) by NaIO4 treatment and then these HA-O particles were reacted with cysteamine (CYs) to obtain thiol groups on the surface of the HA particles. The thiolated HA particles (HA-CYs) were further exposed to radical polymerization with an anionic monomer, 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS), and with a cationic monomer, 3-acrylamidopropyl-trimethylammonium chloride (APTMACl), to generate HA-based ionic hydrogel particles, HA-CYs-AMPS and HA-CYs-APTMACl, respectively. The prepared HA-based anionic and cationic particles illustrated strong pH dependent size variations. We demonstrated that HA-CYs-AMPS and HA-CYs-APTMACl particles can be used as drug delivery vehicles. Trimethoprim (TMP) and naproxen (NN) were used as model drugs in the drug delivery experiments. (C) 2011 Elsevier Ltd. All rights reserved.Öğe Hydrogel particles with core shell morphology for versatile applications: Environmental, biomedical and catalysis(Elsevier Science Bv, 2011) Şahiner, Nurettin; Butun, Sultan; Ilgin, PinarMultipurpose polymeric particles with core-shell morphology were prepared using acrylonitrile (AN) as core forming monomer, and methacrylic acid (MA) and acrylic acid (AAc) as shell monomers via microemulsion polymerization employing a cationic surfactant, hexadecyltrimethylammonium bromide (CTAB). The synthesized particles are amenable for various applications, and demonstrated potential use: (1) as drug delivery devices in biomedical field, (2) in the removal of organic contaminants such as a herbicide (Paraquat) and an organic toxic species (4-nitrophenol (4-NP)) in environmental applications, and (3) as a template for the preparation of Cu catalyst and as a catalysis medium in the reduction of 4-nitrophenol to 4-aminophenol. The prepared p(AN-co-MA) and p(AN-co-AAc) particles were further chemically modified to make the particle more hydrophilic by conversion of nitrile groups to amidoxime groups. The amidoximated particles showed enhanced absorption capacity for organic and metal species and better catalytic activity. Furthermore, the particles were made magnetic field responsive for use in applications, i.e., removal of nanocomposites by an externally applied magnetic field after completing their assignments. (C) 2011 Elsevier B.V. All rights reserved.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 Multiresponsive polymeric particles with tunable morphology and properties based on acrylonitrile (AN) and 4-vinylpyridine (4-VP)(Elsevier Sci Ltd, 2010) Şahiner, Nurettin; Ilgin, PinarWe report the synthesis of amphiphilic, pH and magnetic field sensitive polymeric particles obtained from the modification of poly(acrylonitrile-co-4-vinylpyridine) (p(AN-c-4-VP)) core-shell nanoparticles. The magnetic metal nanoparticles were encapsulated in the microemulsion during the polymerization to achieve magnetic-p(AN-c-4-VP)-composites with various morphology. We further chemically modified each component of p(AN-c-4-VP) particles and its composite to tune the hydrophilicity of the particles. Modification of nitrile (hydrophobic) groups to amidoxime (hydrophilic) groups by amidoximation reaction on AN, and quarternization of nitrogen on pyridine ring of 4-VP were carried out to tune the hydrophilicity and the charge of the particles. The modification also performed on magnetic responsive composites after inclusion of separately prepared magnetic Fe(3)O(4) nanoparticles. It was further demonstrated that these multiresponsive particles can be used as drug carrier. A nonsteroidal and anti-inflammatory drug Naproxen was used as a model active agent for drug loading and the release studies from (p(AN-c-4-VP) based particles in phosphate buffer solution (pH = 7.4) at ambient temperature. (C) 2010 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 POLY 545-Modifiable hydrogel particles based on acrylonitrile core and various shells(Amer Chemical Soc, 2009) Ilgin, Pinar; John, Vijay T.; Şahiner, Nurettin[Anstract Not Available]
