Yazar "Gübbük, İlkay Hilal" seçeneğine göre listele
Listeleniyor 1 - 14 / 14
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe A comparative study and evaluation of magnetic and nonmagnetic hydrogels towards mitigation of di butyl and di ethyl hexyl phthalate from aqueous solutions(ELSEVIER SCIENCE BV, 2016) Qureshi, Umair A.; Gübbük, İlkay Hilal; Ersöz, Mustafa; Solangi, Amber R.; Taqvi, Syed I. H.; Memon, Saima Q.This study was focused on preparation of a new hydrogel adsorbent material based on chitosan, polyvinyl alcohol and magnetic particles. These materials were prepared by varying their ratio and were compared with each other in terms of swelling and adsorption performance for two model endocrine disrupting compounds i.e. dibutyl phthalate (DBP) and diethyl hexyl phthalate (DEHP). Two gels (gel 0 and CS 0.5) were selected for differentiating their adsorption efficiencies as a function of pH, time, concentrations, temperature and interference in batch mode against toxic phthalates. Among the two gels, CS 0.5 was found to be promising than gel 0 and showed better performance toward DBP and DEHP removal. The adsorption mechanism was found to be dominated by hydrogen bonding on gel 0. Additionally, complexation interaction and hydrophobic interactions on CS 0.5 were playing crucial role. The gels can be applied effectively for the elimination of DBP and DEHP pollution from waste water. (C) 2015 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.Öğe Fabrication of Octyltriethoxysilane Langmuir-Blodgett Thin Film(Natl Inst Optoelectronics, 2010) Can, Keziban; Özmen, Mustafa; Gürfidan, L.; Gübbük, İlkay Hilal; Kaymak, E.; Ersöz, Mustafa; Özbek, Zikriye; Çapan, R.In the present work the monolayer properties at the air-water interface of Octyltriethoxysilane (C8TES) molecules are investigated using Langmuir isotherm graphs. Uniform and high quality Langmuir-Blodgett films of these molecules are prepared and characterized by UV-visible, atomic force microscopy and quartz crystal microbalance measurements to determine the deposition quality of these films. High transfer ratio of about 0.99 at a deposition pressure of 11 mN/m was obtained. The contact angle of water was 93.17 degrees with a surface free energy of 23.8 mN/m. The use of soluble triethoxy-based silane coupling agents under anhydrous conditions is shown to produce surfaces with a minimal number of surface defects. C8TES material has been demonstrated to produce well organised LB films and is shown to be a good candidate for application in the field of biosensors.Öğe Immobilization and Characterization of Hemoglobin on Modified Sporopollenin Surfaces(Elsevier Science Bv, 2012) Gübbük, İlkay Hilal; Özmen, Mustafa; Maltaş, EsraHemoglobin was covalently immobilized onto modified sporopollenin surface with different functional groups by chemical reactions to enhance binding ability of protein. In this study, the influence of various silane linker molecules on the capacity of protein binding was studied. For this purpose, activated sporopollenin was modified by 3-aminopropyltriethoxysilane (APTS), 3-chloropropyltrimethoxysilane (CPTS) and (3-glycidyloxypropyl)trimethoxysilane (GPTS). Hemoglobin (Hb) was immobilized on modified sporopollenin surfaces in phosphate buffer saline solution (PBS, pH 7.4) at 4 degrees C. Results showed that GPTS modified sporopollenin surfaces resulted in the highest binding capacity for Hb. Micro porosity of samples was observed through scanning electron microscopy (SEM) and thermal behavior of the samples were studied with thermogravimetric analysis (TGA) within a temperature range: 25-900 degrees C. TGA studies demonstrated the advantages of silane modification for high temperature applications and illustrated differences of the structures due to the different tail groups.Öğe Immobilization of oxime derivative on silica gel for the preparation of new adsorbent(ELSEVIER, 2009) Gübbük, İlkay Hilal; Hatay, İmren; Coşkun, Ahmet; Ersöz, MustafaA new silica gel compound modified 4,4'-oxy-bis(chlorophenylglyoxime) (CPGO) was synthesized and characterized by infrared spectroscopy, elemental analysis and thermogravimetric analysis. The sorption capacity of such a matrix towards Co(II), Ni(II) and Cu(II) from aqueous solutions was studied. The optimum pH values for the separation of these divalent cations on the sorbent were 5.0, 6.0 and 6.0 for Cu, Co and Ni, respectively. The process of metal separation was followed by batch method, and fitted to a Langmuir and Freundlich sorption isotherms. The maximum sorption capacities (0.055, 0.042, and 0.034 mmol g(-1)) were found from the Langmuir equation and the enthalpies of binding were 44.96, 71.63, and 68.14 kJ mol(-1) for Cu, Co and Ni. respectively. The other thermodynamic parameters calculated from the adsorption results were used to explain the mechanism of the adsorption. For example, the Gibbs free energies of binding agree with the spontaneity of the proposed reaction between cations and basic centers. (C) 2009 Elsevier B.V. All rights reservedÖğe Microcontact printing of an alkylsilane monolayer on the surface of glass(SCIENTIFIC TECHNICAL RESEARCH COUNCIL TURKEY-TUBITAK, 2008) Arslan, Gülşin; Özmen, Mustafa; Hatay, İmren; Gübbük, İlkay Hilal; Ersöz, MustafaThis paper describes the use of microcontact printing (mu CP) for patterning of self-assembledm onolayers (SAMs) of (3-aminopropyl)-triethoxysilane (APTES) and octadecyltrichloro silane (OTS) on the surface of glass and functionalization of alkylsilane monolayers. After activation of the glass surface, which was patterned wit h OTS using a poly(dimethylsiloxane) (PDMS) stamp, the remaining bars of the surfaces were treated with APTES and then treated with a dye solution. The characterization of printed silane compounds was confirmed using fluorescence microscopy on the basis of the reaction between terminal amine groups of APTES and thionylchloride of Rhodamine-B dye. Quantitative 3-dimensional pro. ling was performed for the whole modi. cation process by converting of microscopic images to numerical dimensions.Öğe Preparation of calix[4]arene-based sporopollenin and examination of its dichromate sorption ability(SPRINGER, 2013) Sayın, Serkan; Gübbük, İlkay Hilal; Yılmaz, MustafaThe present study describes the preparation of a new calix[4]arene-based sporopollenin material and its application for the removal of Na2Cr2O7 from aqueous solution. The novel calix[4]arene-based sporopollenin material was prepared via the immobilization of dihydrazine amide derivative of p-tert-butylcalix[4]arene (3) onto the modified sporopollenin. The newly prepared calix[4]arene-based sporopollenin is characterized by using different analytical techniques such as FT-IR spectroscopy, scanning electron microscope and Elemental analysis. The batch wise sorption study was carried out to optimize various experimental parameters such as the effect of sorbent dosage, pH, temperature and Cr(VI) anion concentration. It has been found that the sorption of Cr(VI) anion on calix[4]arene-based sporopollenin was highly pH dependent and maximum sorption was achieved at pH 1.5. The sorption behavior was also evaluated by Langmuir, Freundlich and Dubinin Radushkevich isotherms. The value of correlation coefficient (R (2)) showed a good agreement with Freundlich isotherm model. Result of study demonstrated that calix[4]arene-based sporopollenin proved to be highly effective for the removal of Cr(VI).Öğe Preparation of polyaniline montmorillonite clay composites for the removal of diethyl hexyl phthalate from aqueous solutions(TAYLOR & FRANCIS INC, 2016) Qureshi, Umair A.; Gübbük, İlkay Hilal; Ersöz, Mustafa; Solangi, Amber R.; Taqvi, Syed I. H.; Memon, Saima Q.The work presents the synthesis of polyaniline functionalized montmorillonite (PANI/MMT) clay composites and evaluation of their performance as an adsorbent for the mitigation of toxic diethyl hexyl phthalate (DEHP) from water. The formation of composite was confirmed by different analytical techniques such as FTIR, zeta potential analysis, XRD, SEM, and AFM. The adsorption capacity of PANI/MMT was superior to MMT. DEHP followed partition mechanism on PANI/MMT whereas MMT favored surface adsorption mechanism. The performance of PANI/MMT for DEHP removal was unaffected by the change in pH of solution, change in salinity, and hardness contents in aqueous system and consecutive adsorption desorption cycles compared to MMT. Furthermore, both PANI/MMT and MMT exhibited greater adsorption capacities as compared to the previously published work and showed satisfactory performance in real water samples.Öğe Schiff Bazı Türevi İmmobilize Edilmiş Silika Jel Kullanılarak Sulu Çözeltilerden Bakırın Uzaklaştırılması(Selçuk Üniversitesi Fen-Edebiyat Fakültesi, 2006) Gübbük, İlkay Hilal; Koç, Ziya Erdem; Ersöz, MustafaBu çalışmada schiff bazı türevi olan izonitroasetofenon 4- aminobenzohidrazonun silika yüzeyine, 3- kloropropiltrimetoksisilan bileşiği vasıtası ile immobilizasyonu çalışılmıştır.Öğe Surface Modification of Sporopollenin with Calixarene Derivative Characterization and Application for Metal Removal(SPRINGER INTERNATIONAL PUBLISHING AG, 2012) Gübbük, İlkay Hilal; Gürfidan, Leyla; Erdemir, Serkan; Yılmaz, MustafaIn this study, p-tert-butylcalix[4]-aza-crown (CAC) immobilized sporopollenin (Sp) was used as a sorbent for the removal of Cu(II), Pb(II) and Zn(II) from aqueous media. Sporopollenin was firstly functionalized with 3-chloropropyltrimethoxysilane (CPTS) in order to obtain chloro-sporopollenin (Sp-Cl). The Sp-Cl was reacted subsequently with CAC yielding CAC-bonded sporopollenin (Sp-Cl-CAC). The new sorbent was characterized by infrared spectroscopy (FTIR), thermal analysis (TG/DTG) and scanning electron microscopy (SEM). The sorption properties of modified sorbent (Sp-Cl-CAC) are also investigated. The optimum pH values for the separation of metal ions from aqueous solution onto Sp-Cl-CAC were 5.0 for Pb(II) and Cu(II) and 5.5 for Zn(II). The maximum sorption capacities for Cu(II), Pb(II) and Zn(II) were 0.07 (4.44 mg g(-1)), 0.07 (4.58 mg g(-1)) and 0.14 (29.00 mg g(-1)) mmol g(-1), respectively. Sorption thermodynamic parameters of such as free energy (a dagger G (o)), enthalpy (a dagger H (o)), and entropy (a dagger S (o)) were evaluated.Öğe Synthesis and Characterization of Sporopollenin-Supported Schiff Bases and Ruthenium(III) Sorption Studies(SPRINGER, 2012) Şahin, Mustafa; Gübbük, İlkay Hilal; Koçak, NuriyeTwo Schiff base derivatives, (2-pycolylimino)benzen-1,4-diol and (2-pyridylimino)benzen-1,4-diol) were immobilized onto sporopollenin (Lycopodium clavatum) surfaces. The compounds were fully characterized by an infrared spectroscopy, elemental analysis, scanning electron microscopy, and X-ray diffraction techniques. The sorption capacities of the immobilized surfaces toward Ru(III) ions were investigated by batch sorption experiments. For the sorption experiment, the Ru(III) concentration, initial pH, and the temperature effects were studied. The isotherm data of Ru(III) ions were correlated reasonably well as a Freundlich sorption isotherm. The thermodynamic studies showed that the Ru(III) sorption onto immobilized sporopollenin derivatives is a non-spontaneous, endothermic and physical reaction.Öğe Synthesis, characterization, and sorption properties of silica gel-immobilized Schiff base derivative(ACADEMIC PRESS INC ELSEVIER SCIENCE, 2008) Gübbük, İlkay Hilal; Güp, Ramazan; Ersöz, MustafaSilica gel was derivatized with benzophenone 4-aminobenzoylhydrazone(BAH), a Schiff base derivative, after silanization of silica by 3-chloropropyltrimethoxysilane (CPTS) by using a reported method. Characterization of the surface modification was confirmed through infrared spectroscopy, thermogravimetry, and elemental analysis. The immobilized surface was used for Cu(II), Ni(II), Zn(II), and Co(II) sorption from aqueous solutions. The influence of the amount of sorbent, ion concentration, pH, and temperature was investigated. The sorption data followed Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherms. The mean sorption energy (E) of benzophenone 4-aminobenzoylhydrazone (BAH) immobilization onto silica get was calculated from D-R isotherms, indicating a chemical sorption mode for four cations. Thermodynamic parameters, i.e., Delta G, Delta S, and Delta H, were also calculated for the system. From these parameters, Delta H values were found to be endothermic: 27.0, 22.7, 32.6, and 34.6 kJ mol(-1) for Cu(II), Ni(II), Co(II), and Zn(II) metal ions, respectively. AS values were calculated to be positive for the sorption of the same sequence of divalent cations onto sorbent. Negative Delta G values indicated that the sorption process for these three metal ions onto immobilized silica gel is spontaneous. (C) 2008 Elsevier Inc. All rights reserved.Öğe Synthesized of Sporopollenin-Immobilized Schiff Bases and Their Vanadium(IV) Sorption Studies(SPRINGER, 2012) Koçak, Nuriye; Şahin, Mustafa; Gübbük, İlkay HilalThis study investigated the potential use of a biologic polymer Lycopodium clavatum spores (Sporopollenin) for removal of vanadium ions (V(IV)) from aqueous solution. Three Schiff base derivative compounds immobilized sporopollenin were prepared and characterized. Immobilized sporopollenin was characterized via a scanning electron microscope, elemental analysis, infrared spectroscopy and thermal analysis techniques. The sorption capacities of the immobilized surfaces toward V(IV) ions were investigated by batch sorption experiments. V(IV) concentration, initial pH and the temperature effects were studied. The isotherm data of V(IV) ions were correlated reasonably well both Langmuir, Freundlich sorption isotherm. The thermodynamic studies showed that the V(IV) sorption onto immobilized sporopollenin derivatives is a spontaneous, endothermic and a chemical reaction.Öğe Tek moleküllü tabakaların fonksiyonelleştirilmesi ve uygulamaları(Selçuk Üniversitesi Fen Bilimleri Enstitüsü, 2006) Gübbük, İlkay Hilal; Ersöz, MustafaBu çalışmada silanlama vasıtası olan 3- kloropropiltrimetoksi silan, silika jel yüzeyine kovalent olarak bağlanmış ve ardından 4-kloroizonitroasetofenon 4-aminobenzohirazon (I), izonitroasetofenon 4-aminobenzohidrazon (II), benzofenon 4-aminobenzohidrazon (III) molekülleri immobilize edilmiştir. İmmobilizasyon reaksiyonları infrared spektroskopisi termogravimetri, taramalı elektron mikroskobu, elementel analiz cihazları ile karakterize edilmiştir. Her bir yeni adsorban için Cu(II) metal iyonlarının adsorpsiyonu çalışılmıştır. Bu metal iyonu için adsorpsiyona, adsorban miktarı, adsorpsiyon süresi, pH, metal iyon konsantrasyonu ve sıcaklık etkileri araştırılmıştır. Kesikli kap adsorpsiyon çalışmasının sonuçları Freundlich, Langmuir ve Dubinin-Radushkevich (D-R) izoterm modellerine uygulanmıştır. Her bir adsorban için Cu(II) metal iyonlarının sorpsiyonu Langmuir izotermi ile uyum içinde olarak bulunmuştur. Bu izotermin uygun olup olmadığı Scatchart eğrileri çizilerek doğrulanmıştır. Adsorpsiyon izotermlerinden Cu(II) iyonlarının yüzeye kimyasal reaksiyon ile tutunduğu sonucuna varılmıştır. Adsorpsiyon termodinamiği detaylı olarak çalışılmıştır. Termodinamik parametreler, â H , â Go, â So deneysel sonuçların grafiklere uygulanması ile hesaplanmıştır. Sentezlenmiş o olan her bir yeni adsorban maddenin adsorpsiyon çalışması endotermik olarak bulunmuştur. â Go değeri ise immobilize yüzeylerde Cu(II) iyonlarının adsorpsiyonunun kendiliğinden yürüyen mekanizma ile gerçekleştiğini göstermiştir. Son olarak â So her bir adsorban için pozitif olarak bulunmuştur. Bunlara ilave olarak, adsorpsiyon çalışması sürekli sistem veya kolon prosesi ile de gerçekleştirilmiştir. Sonuçlar Origin 6 programına aktarılarak Breakthrough eğrileri çizilmiştir. Eğrilerin alanlarını hesaplamak sureti ile Cu(II) iyonunun mmol metal iyonu/g adsorban miktarları hesaplanmıştır. Bu değerlerin deney koşullarındaki parametreler ile değişimi grafikler ile gösterilmiştir.Öğe The Use of Voltammetry for Sorption Studies of Pb2+ from Aqueous Media using Schiff Base Immobilized Biologic Polymer Material(SPRINGER INTERNATIONAL PUBLISHING AG, 2013) Küçükkolbaşı, Semahat; Erdoğan, Zehra Özden; Koçak, Nuriye; Şahin, Mustafa; Gübbük, İlkay HilalAdsorption by low-cost adsorbents and biosorbents is recognized as an effective and economic method for low-concentration heavy metal. The purpose of this study was to investigate the possibility of the utilization of N,N'-bis(2,5-dihydroxybenzylidene)-1, 4-diaminobenzene (DHDB)-immobilized sporopollenin (Schiff base-immobilized sporopollenin, Sp-DHDB) as a sorbent for removal of lead (II) ion from aqueous solution. The effects of different parameters (such as sorbate concentration, sorbent dosage, and pH of the medium) were investigated by differential pulse anodic stripping voltammetry (DPASV) technique. The experimental data were analyzed by the Freundlich, Langmuir, and Dubinin-Radushkevich (D-R) isotherms. Equilibrium data fitted well with the Freundlich model and the procedure developed was successfully applied for the removal of lead ions in aqueous solutions. This investigation reveals a new, simple, environmentally friendly, and cost-effective method for the removal of lead ions from aqueous solutions by a new Sp-DHDB material.
