Browsing by Author "Durmus, Secil"

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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.
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.