Investigation on selective adsorption of Hg(II) ions using 4-vinyl pyridine grafted poly(ethylene terephthalate) fiber

Arslan, Metin/0000-0001-9432-6877WOS: 000298672800044In the work, poly(ethylene terephthalate) (PET) fibers were grafted with 4-vinyl pyridine (4-VP) monomer using benzoyl peroxide (Bz(2)O(2)) as initiator in aqueous media. The removal of Hg(II) ions from aqueous solution by the reactive fiber was examined by batch equilibration technique. Effects of various parameters such as pH, graft yield, adsorption time, initial ion concentration, and adsorption temperature on the adsorption amount of metal ions onto reactive fibers were investigated. The optimum pH of Hg(II) was found 3. The maximum adsorption capacity was found as 137.18 mg g(-1). Moreover such parameters as the adsorption kinetics, the adsorption isotherm, desorption time and the selectivity of the reactive fiber were studied. The adsorption kinetics is in better agreement with pseudo-first order kinetics, and the adsorption data are good fit with Freundlich isotherms. The grafted fiber is more selective for Hg(II) ions in the mixed solution of Hg(II)-Ni(II), Hg(II)-Zn(II), and Hg(II)-Ni(II)-Zn(II) at pH 3. Adsorbed Hg(II) ions were easily desorbed by treating with 1M HNO3 at room temperature. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012Kirikkale UniverstiyKirikkale UniversityContract grant sponsor: Kirikkale Universtiy

In situ synthesis of silver nanoparticles on modified poly(ethylene terephthalate) fibers by grafting for obtaining versatile antimicrobial materials

GUN GOK, Zehra/0000-0001-6426-0395WOS:000590515900001Because of having high mechanical properties and cheapness of PET textiles, functionalization of them for new properties is an active research area. In the present work, methacrylic acid (MAA)-grafted PET fibers (PET-g-MAA) were obtained by grafting of MAA monomers to PET surface for an antimicrobial material synthesis. The morphologies of the obtained graft copolymers were examined with a scanning electron microscopy (SEM), and the chemical modification after grafting was determined with Fourier-transform infrared spectroscopy (FTIR) analysis. Subsequently, silver ions were adsorbed onto the PET-g-MAA fibers surface and the adsorbed ions to the surface were reduced to silver nanoparticles (AgNPs) by UVC light. The morphology of fiber surfaces modified with MAA and coated with AgNPs was examined by SEM studies, and it was observed that AgNPs were disturbed along the fibers. The presence of silver on the surface was also confirmed by energy-dispersive X-ray spectroscopy (EDS) and energy dispersion X-ray fluorescence spectrometry (EDXRF). The crystalline structure of the original PET fiber, PET-g-MAA fiber and PET-g-MAA fiber modified with AgNPs was investigated by X-ray diffraction (XRD). The thermal properties of the obtained fibers were investigated by thermogravimetric analysis (TGA). The immobilization of AgNPs on the grafted fibers leads to a change on the patterns of TGA curves. The most significant change is the less weight reduction in the temperature range of 200-300 degrees C. Disk diffusion test was performed using Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 25,922) bacteria in order to investigate the antibacterial ability of the obtained fibers, and it was found that the fibers coated with AgNPs had antibacterial effect on both bacterial species. The cytotoxicity of the groups with the best antibacterial properties was determined by MTT test, and the synthesized material did not have cytotoxic effects on L929 fibroblast cells. The material obtained has the potential to be used in antimicrobial applications.Krkkale UniversityThe project was financially supported by Krkkale University with the project number 2019/010. The authors were thankful to Krkkale University for their supporting

Bioremoval of mercury (II) from aqueous solutions by Phragmites australis: Kinetic and equilibrium studies

BASARAN KANKILIC, Gokben/0000-0001-7551-4899WOS: 000450648100011In this study, the removal of mercury (II) ions from aqueous solutions by dried biomass of Phragmites australis was investigated in the batch system. The biomass was characterized by Fourier transform infrared spectroscopy (FT-IR), energy dispersive X-ray fluorescence (ED-XRF), Brunauer-Emmett-Teller (BET) surface area techniques (BET). Inductively Coupled Plasma Atomic Emission Spectrophotometer (ICP-OES, Spectro Blue) was used to analyze Hg(II) concentration and obtained data in batch experiments indicated that Hg (II) was rapidly adsorbed and such adsorption reached equilibrium within 60 min. The initial pH of the solution was effective parameter for Hg (II) biosorption. The biosorption kinetics was in better good fit with pseudo-second order kinetics and the results obtained from the batch experiments were conformed better with the Langmuir isotherm model than Freundlich and D-R isotherm models. The maximum Hg (II) biosorption capacity of P. australis was 20.0 +/- 0.4mg/g. The availability of other metal ions affected mercury biosorption. Adsorption/desorption studies demonstrated that the adsorbed Hg (II) could be desorbed effectively with a 0.1M ethylenediamine tetra-acetic acid (EDTA) solution. The biosorption capacity of the regenerated biosorbent could still be maintained at 72% at the fifth adsorption-desorption cycle. Consequently, it can be said that P. australis can be used as an applicable, cost-efficient, nature friendly biosorbent for treating wastewater. [GRAPHICS] .Kirikkale University Research FundKirikkale University [2017/056]The authors would like to extend their thanks to Kirikkale University Research Fund for their financial support, Project number: 2017/056

Elimination of carcinogenic bromate ions from aqueous environment with 4-vinyl pyridine-g-poly(ethylene terephthalate) fibers

Gunay, Kubra/0000-0002-3522-873X; GUN GOK, Zehra/0000-0001-6426-0395WOS: 000500201200007PubMed: 31485943In 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

Production of 2-hydroxyethyl methacrylate-g-poly(ethylene terephthalate) nanofibers by electrospinning and evaluation of the properties of the obtained nanofibers

inal, murat/0000-0003-3384-5627; GUN GOK, Zehra/0000-0001-6426-0395WOS:000522676800001Nanofiber production was investigated from poly(ethylene terephthalate) (PET) polymers functionalized with hydroxyethyl methacrylate (HEMA) by grafting of HEMA monomers onto the PET fibers. HEMA grafted PET (PET-g-HEMA) copolymers were analyzed by scanning electron microscopy, Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy. PET and PET-g-HEMA were dissolved in trifluoroacetic acid and nanofibers were obtained by electrospinning. It was found that the PET and PET-g-HEMA polymers having grafting yield 20 and 55% could be converted to continuous, smooth, and beadles nanofibers. For characterization of the nanofiber membranes, thermogravimetric analysis, differential scanning calorimeter analysis, surface contact angle measurement, porosity analysis, and mechanical tests were applied. When compared with the original PET nanofibers, the thermal properties and degradation process of PET-g-HEMA nanofibers changed according to the amount of HEMA present in the structure of nanofibers. The contact angles of the nanofibers obtained from PET-g-HEMA polymers decreased whereas the water retention ability of the nanofibers increased compared to original PET nanofibers. The porosity of PET-g-HEMA nanofibers was found be high compared to PET nanofibers and whereas the mechanical properties of PET was higher than PET-g-HEMA nanofibers. The obtained nanofibers can be used in many fields such as biomaterial applications.TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [218S449]TUBITAK, Grant/Award Number: 218S44

Production of 2-hydroxyethyl methacrylate-g-poly(ethylene terephthalate) nanofibers by electrospinning and evaluation of the properties of the obtained nanofibers

GUN GOK, Zehra/0000-0001-6426-0395WOS: 000522676800001Nanofiber production was investigated from poly(ethylene terephthalate) (PET) polymers functionalized with hydroxyethyl methacrylate (HEMA) by grafting of HEMA monomers onto the PET fibers. HEMA grafted PET (PET-g-HEMA) copolymers were analyzed by scanning electron microscopy, Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy. PET and PET-g-HEMA were dissolved in trifluoroacetic acid and nanofibers were obtained by electrospinning. It was found that the PET and PET-g-HEMA polymers having grafting yield 20 and 55% could be converted to continuous, smooth, and beadles nanofibers. For characterization of the nanofiber membranes, thermogravimetric analysis, differential scanning calorimeter analysis, surface contact angle measurement, porosity analysis, and mechanical tests were applied. When compared with the original PET nanofibers, the thermal properties and degradation process of PET-g-HEMA nanofibers changed according to the amount of HEMA present in the structure of nanofibers. The contact angles of the nanofibers obtained from PET-g-HEMA polymers decreased whereas the water retention ability of the nanofibers increased compared to original PET nanofibers. The porosity of PET-g-HEMA nanofibers was found be high compared to PET nanofibers and whereas the mechanical properties of PET was higher than PET-g-HEMA nanofibers. The obtained nanofibers can be used in many fields such as biomaterial applications.TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [218S449]TUBITAK, Grant/Award Number: 218S44