Yazar "Gunay, Kubra" seçeneğine göre listele
Listeleniyor 1 - 11 / 11
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Coating of modified poly(ethylene terephthalate) fibers with sericin-capped silver nanoparticles for antimicrobial application(Springer, 2020) Gok, Zehra Gun; Gunay, Kubra; Arslan, Metin; Yigitoglu, Mustafa; Vargel, IbrahimIn this work, a kind of amine-type PET fibers was synthesized by reacting hexamethylenediamine (HMDA) with methacrylic acid-g-poly(ethylene terephthalate) (PET-g-MAA) fibers for the adsorption of silk sericin-capped silver nanoparticles (S-AgNPs) to produce antimicrobial fibers. Firstly, PET fibers were grafted MAA by using free radical polymerization technique and HMDA was covalently connected to the grafted PET fibers. Then, for S-AgNPs synthesis, 10 mL of AgNO3 solution (1 mM, 5 mM and 10 mM) was mixed with 10 mL of 1% sericin solution at pH 11. The obtained solution was stirred at room temperature for 24 h. The color change from transparent to yellow-brown indicated the formation of S-AgNPs. AgNPs formation was also determined by measuring the absorbance spectra of S-AgNPs between 300 and 600 nm using UV-Vis spectrophotometer. To determine the antimicrobial properties of S-AgNPs, agar-well diffusion tests were performed. 5 mM and 10 mM S-AgNPs groups showed antimicrobial activity on Escherichia coli and Staphylococcus aureus. After characterization of the synthesized S-AgNPs with UV-Vis spectrophotometer, Zetasizer, FTIR and TEM, the modified PET fibers were coated with S-AgNPs (5 mM and 10 mM). The S-AgNPs coated PET fibers were characterized by FTIR, SEM and X-ray fluorescence spectroscopy. The antimicrobial activities of the obtained PET fibers were investigated on S. aureus and E. coli bacteria by using disk diffusion test. It was found that the S-AgNPs coated modified PET fibers exhibited antimicrobial activities toward both gram-positive and gram-negative bacteria. The resulting polymeric PET fibers containing nano-silver can be used as an antimicrobial surface for many applications such as wound dressing.Öğe Effective adsorption of bovine serum albumin by polyethylene terephthalate (PET) fibers modified with glycidyl methacrylate grafting, hexamethylenediamine attachment and Cu2+ adsorption(Springer, 2023) Tastan, Samet; Gunay, Kubra; Arslan, Metin; Yigitoglu, Mustafa; Gok, Zehra GunIn this work, the glycidyl methacrylate-grafted (GMA) PET fibers were modified with hexamethylenediamine (HMDA) attachment and Cu2+ adsorption to synthesize an effective adsorbent for removal of bovine serum albumin (BSA) from the aqueous environment. The original PET fibers were grafted with GMA monomers (PET-g-GMA) at 30%, 50%, 100%, 150% and 200% grafting yields, and HMDA was covalently connected to the fibers through to the epoxy groups. The obtained fibers were characterized with the scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and nuclear magnetic resonance spectroscopy (C-13-NMR) techniques. Afterward, Cu2+ ions were adsorbed to graft copolymers modified with HMDA and it was observed that the protein adsorption ability of Cu2+ ions containing fibers increased. In the adsorption study performed with PET-g-GMA and PET-g-GMA fibers modified with HMDA, the highest Q value was found to be 1.7 and 1.98, respectively, while this value was found to be 16.4 for HMDA-modified PET fibers containing Cu2+ ions. In the adsorption experiments, it was observed that the fibers with the highest BSA adsorption capacity were those modified (with HMDA and Cu2+) PET-g-GMA fibers that have 200% grafting yield. The effects of various parameters on BSA adsorption with the fibers with the highest adsorption capacity were investigated. In the experiment carried out with the selected fibers, pH optimization was made in the range of pH 3-9 and the optimum pH value was found to be pH 5. The Q value of the fiber at this pH was found to be 24.85 mg/g. During the adsorption process carried out at pH 5, it was found that the amount of adsorbed BSA reached equilibrium after the 9 h. Temperature optimization was carried out between 25 and 55 & DEG;C at optimum pH and incubation time. Q values were found as 24.8 mg/g at 25 & DEG;C, 44 mg/g at 35 & DEG;C, 47 mg/g at 45 & DEG;C and 22 mg/g at 55 & DEG;C. According to these results, the temperature at which the maximum adsorption took place was determined as 45 & DEG;C. In the next step where the initial protein concentration upon adsorption was investigated, it was concluded that the fibers reached saturation after an initial concentration of 200 ppm BSA concentration. As a result of the desorption study carried out for 2 h in acetate buffer containing 1 M NaCl at 25 & DEG;C, it was observed that approximately 85% of the loaded protein desorbed from the fibers after 75 min. It has been seen that the modified PET-g-GMA fibers used as adsorbent in this study can be used in separation and purification processes of BSA by adsorption process, due to its advantages such as high production, low cost, high processability, and easy modification.Öğe Efficient removal of cationic dyes from aqueous solutions using a modified poly(ethylene terephthalate) fibers adsorbent(TAYLOR & FRANCIS INC, 2020) Unlu, Nuri; Gunay, Kubra; Arslan, MetinA novel adsorbent was synthesized through functionalization of glycidyl methacrylate-g-poly(ethylene terephthalate) (GMA-g-PET) fibers with iminodiacetic acid (IDA) to give IDA-GMA-g-PET fibers. This adsorbent was then exploited for the removal of Malachite Green (MG) and Rhodamine B (RB) dyes. MG has shown faster adsorption kinetics and equilibrium was attained in 15 mins. and 90 mins. for MG and RB, respectively. IDA-GMA-g-PET fibers showed 100% removal efficiency for MG and RB dyes from the solutions having initial concentrations of 300 mg L(-1)and 200 mg L-1, respectively. Desorption conditions of dyes and reusability of the fibers were also investigated.Öğe Elimination of carcinogenic bromate ions from aqueous environment with 4-vinyl pyridine-g-poly(ethylene terephthalate) fibers(Springer Heidelberg, 2019) Gunay, Kubra; Arslan, Metin; Bozkaya, Ogun; Aluc, Yasar; Gok, Zehra GunIn this study, poly(ethylene terephthalate) fibers grafted with 4-vinyl pyridine (PET-g-4VP) was synthesized with using a radical polymerization method and its removal capacity for bromate ions in the aqueous solution was explored. The synthesized graft copolymer was structurally characterized by scanning electron microscopy (SEM) and Fourier transformed infrared spectroscopy (FTIR). The effect of some parameters such as pH, grafting rate, processing time, and ion concentration on bromate removal was examined with batch experiments. The sorptions of bromate onto the PET-g-4VP fibers were both verified with FTIR and X-ray fluorescence analysis (XRF) and the remaining amount of bromate after adsorption process was determined with an ion chromatography (Shimadzu). Moreover, kinetic and isotherm studies were also performed for adsorption of bromate with the grafted fibers. The point of zero charge (pH(pzc)) of the PET-g-4VP fibers was found to be 7.5 and the fibers removed maximum amount of bromate from aqueous solution at pH 3. Equilibrium time of adsorption was determined to be 75 min and the adsorption kinetic was found to be pseudo-second-order model. It was observed that the increase in the amount of grafted 4VP onto the PET fibers increased the bromate removal capacity of the fibers; however, when the grafting yield of 4VP was over 80%, the bromate removal ability of the fibers decreased. The maximum bromate removal capacity of the PET-g-4VP was determined to be 183 mg/g when the initial bromate amount was 800 mg/L, treatment time was 75 min, pH of the solution was 3, and 4VP grafting yield was 80%. When the initial bromate concentration was higher than 800 mg/L, the removal rate of the PET-g-4VP fibers was not changed. In addition, bromate ion adsorption data indicated compliance with the Freundlich isotherm. The adsorbent fibers obtained by this study may be promising candidates for the removal of bromate ions from the aqueous media.Öğe Removal of anionic dyes with glycidyl methacrylate-grafted polyethylene terephthalate (PET) fibers modified with ethylenediamine(Springer, 2021) Bozkaya, Ogun; Gunay, Kubra; Arslan, Metin; Gun Gok, ZehraIn this work, the epoxy groups of poly (ethylene terephthalate) PET copolymers grafted with glycidyl methacrylate (GMA) were modified with ethylenediamine (EDA) to form exclusive adsorbent for removal of congo red (CR) and acid violet7 (AV-7) in the aqueous environment. The graft copolymers (GMA-g-PET) were synthesized with different grafting yield by a radical polymerization process with using benzoyl peroxide (Bz(2)O(2)) as radical initiator. Amination of GMA-g-PET fibers using EDA was studied in different solvents, and maximum yield (w/w %) was obtained in the toluene. The grafted and modified fibers were analyzed by CHNS organic elemental analyzer, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance spectroscopy (C-13-NMR). By SEM analysis, the morphological changes have been shown after grafting. The chemical changes after grafting and addition of EDA to the fibers have been proven with FTIR, NMR and elemental analysis. The thermal properties of the grafted and aminated fibers were researched with thermogravimetric analysis and differential scanning calorimeter analysis. The removal of dyes by the EDA-GMA-g-PET fibers was investigated in aqueous medium at different conditions. Optimum conditions of different parameters such as pH of medium, graft yield of GMA on the fibers, adsorption duration, initial concentration of dye molecules and effect of graft yield on amination reaction were examined. The optimum pH of CR and AV-7 removal was found 5 and 3, respectively. The removal yield was found about 100% for both dyes while initial concentration of dyes was changed from 10 to 400 mg/L. Adsorbed dyes with the fibers were desorbed with 1 M NaOH at room conditions.Öğe Removing of Congo red from aqueous solution by 2-hydroxyethyl methacrylate-g-poly(ethylene terephthalate) fibers(Springer, 2019) Gok, Zehra Gun; Gunay, Kubra; Arslan, Metin; Yigitoglu, MustafaGrafting of 2-hydroxyethyl methacrylate (HEMA) on poly(ethylene terephthalate) (PET) fibers was carried out via free-radical polymerization technique using benzoyl peroxide as initiator. The obtained copolymers were examined by scanning electron microscope and Fourier-transform infrared spectroscopy analysis, and it was proved that HEMA was successfully grafted onto the PET structure. The synthesized fibrous adsorbents were used to remove Congo red (CR) from aqueous solutions by batch adsorption method. The effects of pH, grafting yield, operation time and dye concentration were studied to find optimal conditions for adsorption of CR by the HEMA-grafted PET (PET-g-HEMA). The obtained results showed that the amounts of adsorbed dye on the PET-g-HEMA lowered with increasing pH. At pH 2, the dye amount adsorbed by the fibers increased with increasing dye concentration up to 70 ppm and grafting yield up to 110%. It was also seen that the adsorption had considerably rapid kinetic and achieved equilibrium within 60 min. The maximum removing abilities of the grafted fibers was found to be 16 mg/g when the beginning concentration of CR was 70 ppm at pH 2. The dye was desorbed from the loaded fibers with 1 M NaOH solution, and it was found that 83% of the adsorbed dye was recovered. The investigations on reusability of the PET-g-HEMA fibers showed that the constructed fibers can be used at least five times without losing adsorption capacities for CR. All these results indicate that the grafting can be used to remove the anionic dyes from the aqueous solution.Öğe Removing selenite ions (SeO32-) from aqueous solutions by 4-vinyl pyridine monomer grafted poly(ethylene terephthalate) fibers and an estimation of its adsorption mechanism over pH dependency of the adsorption(Springer, 2023) Arslan, Metin; Yilmaz, Merve Nur; Gunay, Kubra; Unlu, NuriIn this research, 4-Vinyl pyridine grafted poly(ethylene terephthalate), (4VP-g-PET), fibers were synthesized using the radical polymerization method and used as a novel adsorbent for removing selenite (SeO32-) ions from aqueous solutions. SEM and FTIR spectroscopy were used to examine the structure of the synthesized fibers. Batch experiments were used to conducted the adsorption research. Parameters affecting the adsorption performance like pH, grafting yield, adsorption time, initial selenite concentration and temperature were investigated. The best removal of selenite ions was attained at pH 6. Interestingly, the fibers displayed significant adsorption potential at higher pHs even in highly alkaline environments. Within 3 h, adsorption equilibrium was established, and kinetically, the adsorption process was found to obey the pseudo-first-order kinetic model. Grafting yield increased the amount of selenium adsorption up to 47 percent. The synthesized fibers' maximum selenite adsorption ability was found to be 26.91 mg g(-1). Thermodynamic parameters Delta H-0, Delta S-0 and Delta G(0) of the adsorption were also calculated. The adsorption reaction was determined to be exothermic. The possible adsorption routes were proposed. The synthetic adsorbent, 4VP-g-PET fibers, may be a promising alternative adsorbent for removing selenite from aqueous media.Öğe Synthesis and characterization of PET fibers grafted with binary mixture of 2-methylpropenoic acid and acrylonitrile by free radical: its application in removal of cationic dye(Springer, 2017) Arslan, Metin; Gunay, KubraGrafting of binary vinyl monomer mixtures such as 2-methylpropenoic acid (MPA) and acrylonitrile (AN) onto poly (ethylene terephthalate) fibers (PET) was achieved in an aqueous medium with using benzoyl peroxide like free radical initiator. A new reactively fibrous adsorbent was used for removal of dye such as methylene blue (MB) from aqueous media through batch sorption method. Fibers adsorbent was swelled in solution to support the graft and the subsequent polymerization of MPA/AN onto polyester fibers. Optimum conditions for grafting were discovered and reactive fiber were characterized. Variations of graft yield with time, temperature, initiator concentration and monomer mixture ratio were investigated. The optimum initiator concentration was found to be 8 x 10(-3) mol/L. The percentage of grafting rose steadily with the vinyl monomer mixture monomer concentration (50 %). The optimum temperature and polymerization time were found to be 80 A degrees C and 120 min, respectively. The use of AN and MPA monomers together in grafting produce a significant increased in the graft yield. Experimental studies showed that the percentage removal of MB was a great higher on the MPA/AN grafted PET (MPA/AN-g-PET) fibers than on the original PET fibers. The adsorbed quantity of MB improved with pH and basic pH was appropriate for the elimination of MB. MPA/AN-g-PET fibers removed 98 % of cationic dye when initial concentration diverse from 10 to 80 mg L-1 at pH 9.0. Almost all of the adsorbed cationic dye was eluted by ethanoic acid in methanol. Ten removal-desorption cycles indicated that the reactive fibers were favorable for repetitive use without notable change in removal capacity. Consequently, the MPA/AN-g-PET fibers have demonstrated potential as an effective adsorbent for the extremely effective removal of cationic dyes from aqueous media.Öğe Synthesis and characterization of poly(ethylene terephthalate) fibers grafted with N-(hydroxymethyl) acrylamide by free radical: its application in elimination of Congo red(SPRINGER, 2020) Arslan, Metin; Gunay, Kubra; Gok, Zehra; Yigitoglu, MustafaIn this study, firstly, N-(hydroxymethyl) acrylamide (HMAAm) was grafted on poly(ethylene terephthalate) fibers (PET) by utilizing benzoyl peroxide (Bz(2)O(2)) as an initiator. The alteration in graft percentage with the polymerization time, temperature, concentration of initiator and monomers were investigated. For grafting experiments, the optimum temperature, duration for grafting and initiator concentration were found be 85 degrees C, 4 h and 0.008 M, respectively, and the maximum grafting yield was determined to be 25% at these conditions. After grafting, the morphological and chemical changes on the grafted fibers were examined scanning electron microscopy and Fourier-transform infrared spectroscopy. The thermal properties of the obtained PET fibers were examined with differential scanning calorimeter analysis. In addition, the water absorption capacities of the grafted fibers obtained at optimal conditions were investigated and it was found the maximum percentage of water retention reached 56%. Removal of Congo red (CR) with the grafted fibers was performed using a batch process. The effects of different parameters such as pH, grafting yield of HMAAm, adsorption time and CR concentration on the sorption capacity of the grafted fibers were investigated. The optimal pH for adsorption of CR was found to be 2, and the adsorption process reached equilibrium in 4 h. The amount of adsorbed CR molecules increased with the increment in the grafting yield up to 17%, and the graft copolymers adsorbed CR with 5.62 mg/g efficiency when the initial CR concentration was 80 ppm. The PET-g-HMAAm fibers synthesized in this study can be obtained easily and inexpensively, and the constructed fibers could be used to remove ionic substance from aqueous solution.Öğe Synthesis of amine-functionalized methacrylic acid-g-poly(ethylene terephthalate) fiber and its Congo red removal ability(Springer, 2018) Arslan, Metin; Gunay, KubraThe two kinds of amine-type adsorbents were synthesized by reacting hexamethylenediamine (HMDA) and tetraethylenepentamine (TEPA) with methacrylic acid-g-poly(ethylene terephthalate) (MAA-g-PET) fiber for the removal of Congo red (CR) dye from an aqueous solution. The effect of solvents (toluene, ethanol, 2-propanol, and water) on modification of carboxylic acid group of MAA-g-PET fiber to amine groups (HMDA and TEPA) was investigated. Ethanol and 2-propanol provided a higher amination amount of PET fibers for HMDA and TEPA, respectively. The amination amount of PET fibers increased with increasing concentration of amine (vol%) and graft yield. Effect of various parameters such as pH, graft yield, treatment time, and initial dye concentration on the removal amount of CR on chelating fiber was studied. The removal of CR was higher on the TEPA-MAA-g-PET fiber than on HMDA-MAA-g-PET fiber. The effective pH was 3 for adsorption on HMDA-MAA-g-PET fiber and 6 for adsorption on TEPA-MAA-g-PET fiber. The maximum removal capacities of HMDA-MAA-g-PET fiber and TEPA-MAA-g-PET fiber were 11 and 21 mg/g fiber adsorbent for CR. Consequently, the amine-functionalized MAA-g-PET fiber has demonstrated potential as an effective adsorbent for the removal of acidic dyes from aqueous media.Öğe Synthesis of modified poly(ethylene terephthalate) fibers with antibacterial properties and their characterization(Taylor & Francis As, 2019) Arslan, Metin; Gunay, KubraPoly(ethylene terephthalate) (PET) fibers were grafted with vinyl monomers by utilizing benzoyl peroxide. Grafted PET fibers were modified in optimized conditions with several functional groups such as amine, chlorine, hydrogen peroxide(,) and triclosan to gain antibacterial feature. The second part of this study comprised examination of the antibacterial features of PET fibers via use of Staphylococcus aureus (ATCC 29213) and Escherichia coli (ATCC 25922) bacteria. Kirby-Bauer test is used to study antibacterial properties. The longest zone diameter for Trc-GMA-g-PET fibers was 56 mm for E. Coli whereas the biggest diameter for S. aureus bacteria was 130 mm with Trc-MMA-g-PET fibers.
