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Öğe Adsorption of Cu(II) From Aqueous Solution by Using Modified Fe3O4 Magnetic Nanoparticles(Elsevier, 2010) Özmen, Mustafa; Can, Keziban; Arslan, Gülsin; Tor, Ali; Çengeloğlu, Yunus; Ersöz, MustafaIn this study, surface modification of Fe3O4 nanoparticles (Fe3O4-NPs) was carried out with 3-aminopropyltriethoxysilane (APTES) and glutaraldehyde (GA). The obtained modified-NPs (GA-APTES-NPs) were evaluated for Cu(II) removal from water by adsorption. First, Fe3O4-NPs were synthesized by co-precipitation of Fe2+ and Fe3+ with Fe2+/Fe3+ in a ratio of 1.75 in an ammonia solution, then surface of Fe3O4-NPs was modified with APTES and GA. The morphology and properties of the NPs were examined by Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FT-IR), Thermal Gravimetric Analysis (TGA) and magnetization measurement. The batch experiments showed that modified-NPs can be effectively used to remove Cu(II) from water. Adsorption equilibrium was achieved in 15 min. The adsorption of Cu(II) by GA-APTES-NPs strongly depends on the pH of the solution. Maximum removal of Cu(II) was obtained at pH between 4.0 and 5.3. The isotherm analysis indicated that the sorption data can be represented by both Langmuir and Freundlich isotherm models. The regeneration studies also showed that GA-APTES-NPs could be re-used for the adsorption of Cu(II) from aqueous solutions over three cycles without change in the sorption capacity and magnetization properties.Öğe Assessment of the cytotoxic and genotoxic potential of pillar[5]arene derivatives by Allium cepa roots and Drosophila melanogaster haemocytes(Academic Press, 2020) Liman, Recep; Kurşunlu, Ahmed Nuri; Ciğerci, İbrahim Hakkı; Özmen, Mustafa; Açıkbaş, YaserIn this study pillar[5]arene (P5) and a quinoline-functionalized pillar[5]arene (P5-6Q) which is used for detecting radioactive element, gas adsorption and toxic ions were synthesized. These materials were characterized by Nuclear Magnetic Resonance (NMR), Fourier Transform Infrared (FTIR), elemental analysis, melting point, Mass Spectroscopy, Scanning Electron Microscopy (SEM) and Zeta Potential. The cytotoxic and genotoxic potential of P5 and P5-6Q at distinct concentrations of 12.5, 25, 50, and 100 ?g/mL were also investigated by Allium ana-telophase and comet assays on Allium cepa roots and Drosophila melanogaster haemocytes. P5 and P5-6Q showed dose dependent cytotoxic effect by decreasing mitotic index (MI) and genotoxic effect by increasing chromosomal aberrations (CAs such as disturbed anaphase-telophase, polyploidy, stickiness, chromosome laggards and bridges) and DNA damage at the exposed concentrations. These changes in P5-6Q were lower than P5. Further research is necessary to clarify the cytotoxic and genotoxic action mechanisms of P5 and P5-6Q at molecular levels.Öğe Binding Affinity of Serum Proteins to Epoxy Modified Magnetite Nanoparticles(2012) Maltaş, Esra; Özmen, Mustafa; Yıldız, Salih; Ersöz, MustafaSuperparamagnetic iron oxide nanoparticles (SPIONs) were synthesized by co-precipitating Fe2+ and Fe3+ in an ammonia solution. SPIONs modified with [3-(2,3-epoxypropoxy)propyl] trimethoxy silane, which resulted in the presence of a high population of epoxy groups on the particles surface. The surface functional SPIONs can be bound with active bio-substance, and have a wide application prospect in the fields of biology and medicine. The binding percentage of proteins was studied with epoxy modified SPIONs. Several serum proteins including albumin, ?-globulin, hemoglobin, cytochrome c and myoglobin were studied for immobilization. Epoxy terminated SPIONs were shown the highest binding ability for immobilization of cytochrome c and hemoglobin with 1 and 0.86 mg total protein at a particle concentration of 20 mg/mL among proteins, respectively. This binding ability was also shown by using sodium dodecylsulfate polyacrylamide gel electrophoresis technique (SDS-PAGE). Protein attachments were also examined by Scanning Electron Microscopy (SEM). © 2012 American Scientific Publishers. All rights reserved.Öğe Fabrication of albumin-micropatterned surfaces by colloidal microcontact printing technique(ROYAL SOC CHEMISTRY, 2013) Özmen, Mustafa; Ertekin, Betül; Ersöz, Mustafa; Paunov, Vesselin N.We report a versatile method for selective patterning of solid surfaces with albumin by a combination of microcontact printing of polymer colloids and surface charge aided protein adsorption. The technique allows formation of biocomposite arrays including colloid particles with different albumin functionalities. Micropatterns of functionalised monodisperse colloid particles were formed on the solid surfaces by using a microcontact printing method. We used polyelectrolyte multilayers (PEMs) as a coating system for poly (methylmethacrylate) acrylic acid (PMMA-AAc) patterning on glass substrate and albumin deposition onto colloid patterns by electrostatic interactions. We demonstrate that the colloid micropattern greatly improves the fluorescence imaging contrast for the deposited albumin due to its larger surface area and its immobilisation compared with patterning of albumin on a plane glass surface. This technique can be used to enhance the fluorescence imaging of biomarkers and other assays.Öğe Fabrication of Langmuir-Blodgett thin films of calix[4]arenes and their gas sensing properties: Investigation of upper rim para substituent effect(ELSEVIER SCIENCE SA, 2014) Özmen, Mustafa; Özbek, Zikriye; Büyükçelebi, Sümeyra; Bayrakçı, Mevlüt; Ertul, Şeref; Ersöz, Mustafa; Çapan, RıfatThis study reports the characterization and organic vapor sensing properties of Langmuir-Blodgett (LB) thin films of calix[4] arene derivatives that contain different numbers of tert butyl groups on their upper rims. Surface pressure-area isotherms show that very stable monolayers are formed at the air-water interface. The LB films are deposited onto different substrates, which allowed us to characterize the films by contact angle measurements, quartz crystal microbalance (QCM), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The results indicate that good quality, uniform LB films can be prepared with transfer ratios of over 0.95. Meanwhile, our QCM results show that the deposition of LB film layers depends heavily on the number of p-tert-butyl groups and calix[4]arene with four p-tert-butyl groups yields the highest slope with a mass value of 1145 ng per layer. Furthermore, our AFM and SEM studies reveal a dense surface morphology for all prepared LB films. The kinetic response of calix[4]arenes containing p-tert-butyl groups and without p-tert-butyl groups as an LB film to chloroform, benzene, toluene, and ethanol vapors were investigated as a function of time. After attaching tert-butyl groups onto the calix[4]arene structure, the response of LB film to chloroform vapor increased. LB films of compounds 1-4 yield a response to all vapors and more often select chloroform with a larger, faster, and more reproducible response. We thus conclude that these calix[4]arenes could be applied to research concerning vapor sensing devices operating at room temperature. (C) 2013 Elsevier B.V. All rights reserved.Öğe Fabrication of LB thin film of pillar[5]arene-2-amino-3-hydroxypyridine for the sensing of vapors(Elsevier B.V., 2020) Kurşunlu, Ahmet Nuri; Açıkbaş, Yaser; Özmen, Mustafa; Erdoğan, Matem; Çapan, RıfatThis paper reported that a novel pillar[5]arene derivative (P5-AP) concluding ten 2-Amino-3-hydroxypyridine fragments was structured for preparing a macrocycle with an appropriate cavity for sensing harmful organic vapors. Thin films of P5-AP were fabricated using a modified Langmuir–Blodgett (LB) method and the formation of these thin films was verified by Quartz Crystal Microbalance (QCM) and UV–vis absorption spectrum. The interaction or response of P5-AP film coated onto suitable substrates to six different organic vapors (aromatic and chlorinated aliphatic hydrocarbons) was investigated via QCM and Surface Plasmon Resonance (SPR) methods. The overall results showed that gas sensor components comprising of P5-AP LB films have potentials for rapid and sensitive detection harmful organic vapors. © 2020 Elsevier B.V.Öğe Fabrication of novel anisotropic magnetic microparticles(ROYAL SOC CHEMISTRY, 2009) Dyab, Amro K. F.; Özmen, Mustafa; Ersöz, Mustafa; Paunov, Vesselin N.We report a novel technique for fabrication of magnetically anisotropic microparticles based on "arresting" of the alignment of oleic acid coated magnetite nanoparticles (OCMNs) dispersed within the oil drops of a polymerisable oil-in-water emulsion. This was achieved by polymerising the oil drops after gelling the continuous aqueous phase in the presence of an external magnetic field. This approach allowed us to produce magnetic Janus particles with anisotropic optical and magnetic properties which form unusual zig-zag chains and structures when exposed to an external magnetic field. We studied the magnetic properties of these novel microparticles and showed that they retained remanence magnetisation with high coercivity values indicative of ferromagnetic behaviour. This indicates that the composite polymeric Janus microparticles posses a net magnetic dipole and behave like micromagnets due to the "arrested" orientation of the OCMNs in their polymeric matrix. Utilizing the same technique, magnetic Janus microparticles have been prepared based on emulsions stabilised only by OCMNs without the use of surfactants, and the effect of pH of continuous aqueous phase on the morphology of these microparticles has been investigated.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 Facilitated transport of Cr(VI) through a novel activated composite membrane containing Cyanex 923 as a carrier(ELSEVIER, 2009) Arslan, Gülşin; Tor, Ali; Muslu, Harun; Özmen, Mustafa; Akın, İlker; Çengeloğlu, Yunus; Ersöz, MustafaThis paper describes the facilitated transport of Cr(VI) through a novel Activated Composite Membrane (ACM) containing Cyanex 923 as a carrier. The ACM was prepared by immobilization of the Cyanex 923 on a polysulfone support by means of interfacial polymerisation. The prepared ACM was characterized by using scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques and contact angle measurements. The effect of feed phase composition, carrier concentration of the casting solution and stripping phase composition on the transport of Cr(VI) was investigated. When the feed phase contained 1 X 10(-3) M Cr(VI) at pH 1.0, 99% of Cr(VI) was transported through the ACM (prepared with 3% carrier solution) by using 1 M NaOH as a stripping phase. Furthermore, Cr(VI) was preferably transported in the presence of various metal ions (i.e., Cr(III), Ni(II), Cu(II), Zn(II), Cd(II), Co(II), etc.) and sulphate and nitrate ions had no negative effect on the transport of Cr(VI). The results also showed that transport efficiency of the ACM was reproducible and it could be efficiently used in the long-term separation processes instead of supported liquid membrane (SLM). (C) 2009 Elsevier B.V. All rights reserved.Öğe Haloalkanes and aromatic hydrocarbons sensing using Langmuir-Blodgett thin film of pillar[5]arene-biphenylcarboxylic acid(ELSEVIER SCIENCE BV, 2019) Kurşunlu, Ahmed Nuri; Açıkbaş, Yaser; Özmen, Mustafa; Erdoğan, Matem; Çapan, RıfatHere, a pillar [5]arene derivative including biphenylcarboxylic acid groups was designed for obtaining a macrocycle with an ideal cavity for volatile organic compounds. The pillar[5]arene -biphenylcarboxylic acid (P5-BPCA) based Langmuir-Blodgett (LB) thin films were produced onto 50 nm thick gold-coated glass and 3.5 MHz quartz crystal substrates to form a thin film chemical sensor element. Surface plasmon resonance (SPR) and Quartz crystal microbalance (QCM) techniques were employed to characterize all the P5-BPCA LB thin film layers. The mass of LB film layer loaded onto a quartz crystal and the resonance frequency shifts per layer were determined to be 711.71 ng per layer (2.68 ng mm(-2)) and 48.24 Hz per layer, respectively. The P5-BPCA LB thin film sensor element was exposed to various haloalkane and aromatic hydrocarbon vapors. The sensitivities of the P5-BPCA LB film sensor were determined between 1.776 and 3.976 Hz ppm(-1). Sensitivity with detection limits were obtained between 0.754 and 1.689 ppm against organic vapors. The results showed that P5-BPCA LB thin film was highly selective with a large response to chloromethane vapor.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 albumin on aminosilane modified superparamagnetic magnetite nanoparticles and its characterization(ELSEVIER SCIENCE BV, 2009) Can, Keziban; Özmen, Mustafa; Ersöz, MustafaMagnetite nanoparticles (NPs) were synthesized by co-precipitating Fe2+ and Fe3+ in an ammonia solution. Magnetite NPs coated with 3-aminopropyltriethoxysilane (APTES) were prepared by silanization reaction. After activated with glutaraldehyde (CA), human serum albumin was covalently immobilized on these magnetic NPs. The influence of three different buffer solutions on covalent immobilization was studied. phosphate buffer saline solution (PBS) was shown the highest binding ability for immobilization process compared to other buffer solutions. The morphology and properties of these magnetic NPs were examined by transmission electron eicroscopy (TEM), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA) and magnetization measurement. (C) 2009 Elsevier B.V. All rights reserved.Öğe Immobilization of albumin on indium-tin oxide (ITO) surface via isocyanate linkage(ELSEVIER SCIENCE SA, 2009) Özmen, Mustafa; Can, Keziban; Ersöz, MustafaIndium-tin oxide (ITO) surfaces have become a very important material for use as a conducting substrate, recently. Immobilization of biological molecule onto the ITO is a fundamental step in the development of biosensors. In this paper, attachment of albumin was carried out using ITO as a support. Albumin was covalently immobilized onto self-assembled monolayer (SAM) of (3-isocyanatopropyl) triethoxysilane (IPTES) on ITO surface. Isocyanato-functionalized organic film was prepared by self-assembling on active ITO surface. After that, human serum albumin (HAS) which was prepared in Phosphate-Buffered Saline Solution (PBS: pH 7.4, 0.1 M), was covalently immobilized on IPTES modified ITO surface. The study here can help us understand the influence of monolayer and electrochemical behavior on ITO surface. Characterization of stepwise changes of active ITO, IPTES/ITO and albumin/IPTES/ITO surfaces were carried out using contact angle (CA) measurements, fluorescence microscopy, atomic force microscopy (AFM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV), respectively. (C) 2009 Elsevier B.V. All rights reservedÖğe Immobilization of albumin on magnetite nanoparticles(ELSEVIER SCIENCE BV, 2011) Maltaş, Esra; Özmen, Mustafa; Vural, Hasibe Çingilli; Yıldız, Salih; Ersöz, MustafaThe magnetite (Fe3O4) nanoparticles were prepared by the co-precipitation of ferrous and ferric salts with NH4OH, and then modified with 3-aminopropyltriethoxysilane (APTES) by silanization reaction and subsequent reaction with glutaraldehyde (GA) to obtain functional groups on their surface. The influence of different terminated groups on protein binding was studied with bare and modified magnetite nanoparticles. Amine terminated magnetite nanoparticles were shown the highest binding ability for immobilization process compared to Fe3O4 NPs and GA bonded NPs. This binding ability was shown by using sodium dodecyl polyacrylamide gel electrophoresis technique (SDS-PAGE). Albumin attached magnetite nanoparticles were also examined by Scanning Electron Microscopy (SEM). (C) 2011 Elsevier B.V. All rights reserved.Öğe Investigation of environmentally volatile pollutants sensing using pillar[5]arene-based macrocycle Langmuir-Blodgett film(SPRINGER HEIDELBERG, 2020) Özmen, Mustafa; Kurşunlu, Ahmed Nuri; Açıkbaş, Yaser; Erdoğan, Matem; Çapan, RıfatThis study presented that a novel pillar[5]arene-appended salicylaldehyde (P5-S) was structured in a suitable cavity, which plays an important role in macrocyclic host-guest interactions. P5-S thin films were fabricated and characterized via Langmuir-Blodgett (LB), UV-vis spectrophotometer and quartz crystal microbalance (QCM) techniques, respectively. A QCM sensor deposited with an LB thin film of P5-S macrocyclic molecule was used as a sensitive material for the detection of aliphatic chlorinated hydrocarbons and aromatic hydrocarbons such as carbon tetrachloride, chloroform, dichloromethane and benzene, toluene and m-xylene vapors, respectively. These harmful organic vapors are a source of danger to the environment and are a group of important environmental pollutants. Similar tests were performed with surface plasmon resonance (SPR) technique, and SPR kinetic results were obtained in good agreement with QCM kinetic results. Also, the sensitivity and detection performance of the P5-S QCM chemical sensor to six different pollutants were determined.Öğe Katı destek yüzeyleri üzerine kolloidal yapıların mikro ve nano desenlenmesi ve onların fonksiyonlandırılması(Selçuk Üniversitesi Fen Bilimleri Enstitüsü, 2011-11-18) Özmen, Mustafa; Ersöz, MustafaYapılan bu çalışmada katı yüzeyler üzerine hazırlanacak olan kolloid desenleri mikrokontak printing metodu kullanılarak hazırlanmıştır. Ardından desenlenmiş kolloid üzerine biyomolekülün adsorpsiyonu incelenmiştir. Uygulama kısmında ise maya ve klorella hücrelerinin katı yüzey üzerinde biyofilm oluşturması araştırılmış ve tabakalı kaplama metodu kullanılarak biyofilmin yüzeyde desenlerinin oluşturulması ve oluşan desenin çözelti ortamına aktarılması gerçekleştirilmiştir. Bu çalışmada yüzeylerin temizlenmesi ve aktifleştirilmesi için RCA prosedürü uygulanmıştır. Mikrokontakt baskılama metodu için master kalıplar, Hull Üniversitesi Fizik Bölümü Laser Laboratuvarında hazırlanmıştır. Kolloidal madde olarak PMMA-AAc sentezi yapılmış ve yaklaşık 250-350 nm boyutta küresel kolloid kürecikleri elde edilmiştir. Sentezlenen kolloidal maddenin katı yüzey üzerine mikrokontakt baskılama işleminden sonra FITC-Albumin biyomateryalinin kolloid deseninin üzerine adsorplanması amaçlanmıştır. Ayrıca FITC-Albumin biyomateryalinin katı yüzey üzerine kolloid kullanmadan doğrudan mikrokontakt baskılama metodu ile desenlenmesi de gerçekleştirilmiştir. Bu amaçla negatif yüklü yüzey pozitif yüklü bir polielektrolit kullanılarak FITC-Albuminin yüzeye desenlenmesi elektrostatik olarak kolaylaştırılmıştır. Çalışmanın uygulama aşamasında katı yüzey üzerinde tabakalı kaplama metodu kullanılarak maya ve klorella hücrelerinin biyofilmi oluşturulmaya çalışılmıştır. Ayrıca maya hücrelerinin biyofilm deseni katı yüzey üzerinde oluşturulmaya çalışılmıştır. Bunun için ticari olarak temin edilmiş grid yapılar kullanılmıştır. Elde edilen biyofilm deseni çözelti ortamına aktarılmış ve biyofilmin yapısının bozulmadığı ve aktivitesini halen koruduğu gözlenmiştir. Yüzeylerin karakterizasyonu için atomik kuvvet mikroskobu, su temas açısı ölçüm cihazı, optik ve floresans mikroskobu, taramalı elektron mikroskobu kullanılmıştır. Kolloid yüzeyinin ve biyomateryallerin yük yoğunlukları için ise zeta potansiyel ölçüm cihazı kullanılmıştır.Öğe 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 Optical Properties and Swelling Behavior of Fe3O4 Functionalized Graphene Oxide Composite Thin Film(IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2017) Açıkbaş, Yaser; Baş, Salih Zeki; Özmen, Mustafa; Çapan, Rıfat; Erdoğan, MatemThe optical characterization and gas sensing properties of Fe3O4 functionalized graphene oxide ( GO) composite [Fe3O4-(3-aminopropyl) triethoxysilane GO (APTES-GO)] thin film are discussed in this paper by using spin coating, UV-visible spectroscopy, transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction measurements, Surface Plasmon Resonance, and quartz crystal microbalance (QCM) techniques. The Fe3O4-APTES-GO thin films with thickness in the range between 14 and 31 nm have been successfully prepared, when films were spun at speeds between 1000 and 4000 rpm with a refractive index values of between 1.32 and 1.37. In this paper, the swelling behaviors of the Fe3O4-APTES-GO thin films were investigated with respect to volatile organic compounds (VOCs) at room temperature by using the QCM method. The swelling processes could be investigated using the early-time Fick's law of diffusion. Diffusion coefficients were found to be 24.17 x 10(-16), 13.99 x 10(-16), 3.97 x 10(-16), and 1.73 x 10(- 16) cm(2) s(-1) for dichloromethane, chloroform, benzene, and toluene vapors, respectively. The response of the Fe3O4-APTES-GO films to the these VOCs has been investigated in the conditions of physical properties of the solvents, and the films were obtained to be largely sensitive to dichloromethane and chloroform vapors compared with other studied vapors.Öğe Preparation and gas sensing properties of Langmuir-Blodgett thin films of calix[n]arenes: Investigation of cavity effect(ELSEVIER SCIENCE SA, 2014) Özmen, Mustafa; Özbek, Zikriye; Bayrakçı, Mevlüt; Ertul, Şeref; Ersöz, Mustafa; Çapan, RıfatCharacterization and organic vapor sensing properties of Langmuir-Blodgett (LB) thin films of calix[n]arene (n=4, 6, 8) derivatives are reported in this work. Surface pressure-area isotherm graph shows that very stable monolayers are formed at the water surface. The results indicate that good quality, uniform LB films can be prepared with a transfer ratio of over 0.95. Calix[n]arene LB films have been characterized by contact angle measurements, quartz crystal microbalance (QCM), scanning electron microscopy (SEM) and atomic force microscopy (AFM). LB film of calix[8]arene which has the largest cavity yields a gradient with a mass value of 773 ng per layer according to the QCM results. AFM and SEM images showed a dense surface morphology obtained for all samples. QCM system was used for the measurement of sensor response against chloroform, benzene, toluene and ethanol vapors. These LB film samples yield a response to all vapors with a large, fast, and reproducible due to the adsorption of vapors into the LB film structures. Among them, calix[8]arene LB film has higher sensitivity toward the organic vapors because of a large cavity size. This study can be concluded that the cavity size of calix[n]arene molecule could have an important role in the research area of room temperature vapor sensing devices. (C) 2014 Elsevier B.V. All rights reserved.Öğe Preparation of Langmuir-Blodgett thin films of calix[6]arenes and p-tert butyl group effect on their gas sensing properties(ELSEVIER SCIENCE BV, 2015) Özmen, Mustafa; Özbek, Zikriye; Bayrakçı, Mevlüt; Ertul, Şeref; Ersöz, Mustafa; Çapan, RıfatOrganic vapor sensing properties of Langmuir-Blodgett (LB) thin films of p-tert-butyl calix[6]arene and calix[6]arene, and their certain characterization are reported in this work. LB films of these calixarenes have been characterized by contact angle measurement, quartz crystal microbalance (QCM), scanning electron microscopy (SEM) and atomic force microscopy (AFM). QCM system was used for the measurement of sensor response against chloroform, benzene, toluene and ethanol vapors. Forming of stable monolayers was observed at the water surface using surface pressure-area isotherm graph. The results indicate that good quality, uniform LB films can be prepared with a transfer ratio of over 0.95. Due to the adsorption of vapors into the LB film structures; they yield a response to all vapors as of large, fast, and reproducible. (C) 2015 Elsevier B.V. All rights reserved.
