Browsing by Author "Ilgin, Pinar"

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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; Ozay, Ozgur
This 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.
Adsorption of Methylene Blue From Aqueous Solution Using Poly(2-Acrylamido Acid-Co Methacrylate) Hydrogel Crosslinked by Activated Carbon
(Taylor & Francis inc, 2023) Ilgin, Pinar; Onder, Alper; Kivanc, Mehmet Riza; Ozay, Hava; Ozay, Ozgur
This 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.
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.; Sahiner, Nurettin
Colloidal Drug Carries From (Sub)micron Hyaluronic Acid Hydrogel Particles With Tunable Properties for Biomedical Applications
(Elsevier Sci Ltd, 2010) Ilgin, Pinar; Avci, Gulden; Silan, Coskun; Ekici, Sema; Aktas, Nahit; Ayyala, Ramesh S.; Sahiner, Nurettin
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.
A Novel Ph-Responsive P(aam-co-metac)/Mmt Composite Hydrogel: Synthesis, Characterization and Its Absorption Performance on Heavy Metal Ions
(Taylor & Francis inc, 2015) Ilgin, Pinar; Durak, Halil; Gur, Aycan
In this study, the preparation and characterization of the novel pH-sensitive poly (acrylamide-co-2-methacryloyloxy) ethyltrimethyl ammonium chloride)/montmorillonite (p(AAm-co-METAC)/MMT) composite superabsorbent hydrogels and their selective metal absorbtion properties were investigated. The adsorption of metal ions is highly dependent on the initial feed concentration, contact time, pH of the metal solution and adsorbent doses. The results were analyzed both by the Langmuir and Freundlich isotherms and the adsorption is found to follow pseudo-second-order kinetics. The adsorption capacity followed the order Zn2+>Ni2+>Cu2+>Pb2+ and the maximum adsorption capacities of them were similar to 320, 285, 240 and 120 (mg g(-1)), respectively.
Novel Stimuli-Responsive Hydrogels Derived From Morpholine: Synthesis, Characterization and Absorption Uptake of Textile Azo Dye
(Springer, 2017) Ilgin, Pinar; Ozay, Ozgur
A 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.
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; Ozay, Ozgur; Ozay, Hava; Ilgin, Pinar
Poly((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.
Synthesis and Characterization of 2-hydroxyethylmethacrylate/2-(3-indol-yl)ethylmethacrylamide-based Novel Hydrogels as Drug Carrier With in Vitro Antibacterial Properties
(Wiley, 2017) Ilgin, Pinar; Zorer, Ozlem Selcuk; Ozay, Ozgur; Boran, Gokhan
In this study, a new cationic monomer 2-(3-indol-yl)ethylmethacrylamide (IEMA) derived from tryptamine was synthesized in a single step and characterized by Fourier transform infrared (FTIR), H-1-NMR, and C-13-NMR. Then, one-step preparation of novel poly[2-hydroxyethylmethacrylate-c-2-(3-indol-yl)ethylmethacrylamide], or p(HEMA-c-IEMA), copolymeric hydrogels has been performed successfully with IEMA and 2-hydroxyethylmethacrylate (HEMA) as monomers using free radical aqueous polymerization. The hydrogels were characterized with scanning electron microscopy, FTIR, elemental analysis, thermogravimetric analysis, and texture profile analysis instruments. p(HEMA-c-IEMA) hydrogels were used for swelling, diffusion, drug release, and antibacterial activity studies. The drug-release behavior of the hydrogels was determined as a function of time at 37 degrees C in pH1.2 and 7.2. The swelling and drug-release studies showed that an increased IEMA amount caused a higher increase in swelling and drug-release values. Additionally, zero-order, first-order, and Higuchi equation kinetic models were applied to the drug-release data, and the data fit well in the Higuchi model, and the Peppas power-law model was applied to the release mechanism. Finally, the antibacterial activities of the hydrogels were screened against Gram-positive bacteria (Bacillus cereus and Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli and Salmonella typhimurium). (c) 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45550.
Synthesis and Characterization of a New Fast Swelling Poly(epma-Co as Superabsorbent Polymer for Anionic Dye Absorbent
(Springer, 2015) Ilgin, Pinar; Gur, Aycan
A novel superabsorbent polymer poly(2,3-epoxypropyl methacrylate-co-2-(methacryloyloxy)ethyl trimethyl ammonium chloride), p(EPMA-co-METAC), was prepared simply by free radical aqueous copolymerization reaction of 2,3-epoxypropyl methacrylate (EPMA) and 2-(methacryloyloxy)ethyl trimethyl ammonium chloride (METAC) using N,N'-methylenebisacrylamide (MBA) as a cross-linking agent and ammonium persulfate (APS) as a free radical initiator. The chemical structures of hydrogel were confirmed by FTIR and elemental analysis. The swelling behavior of the hydrogel samples was investigated under different experimental conditions such as time, pH, ionic strength and different media. In the second part of this study, the superabsorbent hydrogels were tested for the removal of an anionic dye, i.e., Coomassie Brilliant Blue G-250 (CBB), a molecule having a marked amphiphilic character, from aqueous environment. Finally, isotherm adsorption data of dye on hydrogels were modeled according to Langmuir and Freundlich isotherm models. The results revealed that the experimental data was correlated by both of them. Also, the kinetic parameters for the adsorption process of the dye were investigated based on the different kinetic models such as pseudo-first-order and second-order models and the adsorption kinetics followed well the pseudo-second-order model. Novel superabsorbent polymer samples also show good anionic dye absorbency and excellent swelling ability. As a result, p(EPMA-co-METAC) hydrogel appeared to be suitable for the removal of CBB from aqueous solutions.
Synthesis of P(hema-Co Nanocomposite Hydrogel With Vinyl-Function Montmorillonite Nanoparticles and Effective Removal of Methyl Orange From Aqueous Solution
(Taylor & Francis inc, 2023) Onder, Alper; Kivanc, Mehmet Riza; Ilgin, Pinar; Ozay, Hava; Ozay, Ozgur
It 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.
Synthesis, Characterization, and in Vitro Drug Release Properties of Aunps/P(aetac-co-vi) Nanocomposite Hydrogels
(Springer Heidelberg, 2021) Durmus, Secil; Yilmaz, Betul; Kivanc, Mehmet Riza; Onder, Alper; Ilgin, Pinar; Ozay, Hava; Ozay, Ozgur
In 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 degrees 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.
Temperature and Magnetic Field Responsive Hyaluronic Acid Particles With Tunable Physical and Chemical Properties
(Elsevier, 2011) Ekici, Sema; Ilgin, Pinar; Yilmaz, Selahattin; Aktas, Nahit; Sahiner, Nurettin
We report the preparation and characterization of thiolated-temperature-responsive hyaluronic acid-cysteamine-N-isopropyl acrylamide (HA-CYs-NIPAm) particles and thiolated-magnetic-responsive hyaluronic acid (HA-Fe-CYs) particles. Linear hyaluronic acid (HA) crosslinked with divinyl sulfone as HA particles was prepared using a water-in-oil micro emulsion system which were then oxidized HA-O with NaIO4 to develop aldehyde groups on the particle surface. HA-O hydrogel particles were then reacted with cysteamine (CYs) which interacted with aldehydes on the HA surface to form HA particles with cysteamine (HA-CYs) functionality on the surface. HA-CYs particles were further exposed to radical polymerization with NIPAm to obtain temperature responsive HA-CYs-NIPAm hydrogel particles. To acquire magnetic field responsive HA composites, magnetic iron particles were included in HA to form HA-Fe during HA particle preparation. HA-Fe hydrogel particles were also chemically modified. The prepared HA-CYs-NIPAm demonstrated temperature dependent size variations and phase transition temperature. HA-CYs-NIPAm and HA-Fe-CYs particles can be used as drug delivery vehicles. Sulfamethoxazole (SMZ), an antibacterial drug, was used as a model drug for temperature-induced release studies from these particles. (C) 2010 Elsevier B.V. All rights reserved.