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Research Project Benzotellurodiazol Esaslı Yeni Anorganik-organik Melez Elektroaktif Monomerlerin Sentezi(2017) Cihaner, Atilla; Işık, Murat; Algı, FatihBu çalışmada benzotelluradiazol ve benzimidazol birim esaslı altı farklı elektron verici-alıcı- verici (V-A-V) monomerin sentezi, karakterizasyonu ve polimerizasyonu rapor edilmeye çalışılmıştır. Benzotelluradiazol esaslı V-A-V monomerleri başarı ile sentezlenememiş olsada benzimidazole esaslı V-A-V monomerleri başarılı bir biçimde sentezlenmiş, karakterize edilmiş ve elektrokimyasal olarak polimerleştirilmiştir. Benzotiyadiazol ve benzoselenadiazol türevleri gibi, tiyofen ve 3,4-alkilendioksitiyofen elektron verici birimleri ile birleştirilmiş benzimidazole birimleri içeren polimerler 1.50 eV ve 1.57 eV aralığında dar band aralığı değerlerine sahip olup dışarıdan uygulanan potensiyel altında elektrokromik özellikler göstermiştir. Diğer bir taraftan benzotelluradiazol türevleri için daha önceden literatürde rapor edilen sentez reçeteleri bu çalışmadaki benzotelluradiazol esaslı V-A-V monomerlerinin sentezinde çalışmamıştır. Malesef literatürde benzotiyadiazol veya benzoselenadiazol içerikli polimerlerin benzotelluradiazol içerikli polimerlerin dönüşümünde kullanılan sentez reçeteleri monomer ve oligomer sentezlerinde çalışmamıştır. Bunun yanında teorik çalışmalar benzotelluradiazol esaslı V-A-V tipi monomerlerin ve oligomerlerin oda sıcaklığında kararlı bileşikler olduğunu ve diğer elektron alıcı benzerleri ile karşılaştırıldığında daha düşük band aralıklı polimerler verebileceğini göstermiştir. Sonuç olarak benzotelluradiazol esaslı monomerler sentezleyebilmek için bilinen sentez reçetelerinin dışında yeni stratejilerin ve reçetelerin uygulanması gerekmektedir. Bu konu üzerindeki çalışmalar sürmektedir.Article Deposition and Characterization of Znsnse2 Thin-Films Deposited by Using Sintered Stoichiometric Powder(2019) Sürücü, Özge Bayraklı; Güllü, Hasan HüseyinIn this work, ZnSnSe2 (ZTSe) thin films were deposited using crystalline powder grown by vertical Bridgman-Stockbarger technique. The deposition process was carried out by means of e-beam evaporation on the well-cleaned soda lime glass substrates and keeping them at the substrate temperature of 200°C. The structural, optical and electrical properties of ternary ZTSe thin films were investigated depending on the annealing temperature at 250 and 300°C. X-ray diffraction analysis showed that as-grown films were in amorphous structure, however annealing at 250°C triggered the crystallization on the preferred ternary structure and annealing at 300°C resulted in the changes from amorphous to the polycrystalline structure. Using the compositional analysis, the detail information about the stoichiometry and the segregation mechanisms of the constituent elements in the structure were determined for both as-grown and annealed samples. In addition, they were morphologically characterized using scanning electron microscopy technique. The electrical properties were analyzed using temperature dependent dark- and photo-conductivity measurements. From the variation of electrical conductivity as a function of the ambient temperature, the current transport mechanisms and corresponding activation energies at specific temperature intervals for each sample were determined. The optical properties for the ZTSe thin films were studied depending on the structural changes with annealing.Research Project Binükleer Rodyum Komplekslerinin, $[rh_2(b-b)_4l_2] (b-b=ch_3co_2^-, So_4^{2-}, Hpo_4^{2-})$ Elektrokimyasal Özellikleri, Elektron Soğurma Spektrumları ve Elektron Yapıları(2003) İşçi, Hüseyin; Özbek, Özge; Önal, M. Ahmet; Yaman, Şeniz ÖzalpBu çalışmada, çeşitli dirodyum(II,II) kompleksleri, [M2(B-B)4L2]n ve [NH4]n[M2(B-B)4L2] (M= Rh(II); B-B= O2CCH3\", SO42\\ CO32\" ve H2PO4\"; L = CH3OH, H2O), hazırlanmış, komplekslerin elektrokimyasal davranımları ve elektron soğurma spektrumları çalışılmıştır. Yükseltgenme-indirgenme tepe gerilimlerinin değişimleri ile komplekslerin HOMO ve LUMO enerji seviyelerini ilişkilendirebilmek amacıyla çeşitli eksenel ligandları (L = H2O, CH3CN, Cl\", Br\", SCN\"), içeren komplekslerin yükseltgenme tepe gerilimleri dönüşümlü voltametre yöntemi ile ölçülmüştür. Elektron soğurma spektrumlarmın açıklanması da yine elektrokimyasal veriler kullanılarak yapılmıştır. Komplekslerin sabit potansiyel elektrolizleri çeşitli çözücüler içinde yapılmış ve ürünlerin oluşumları elektroliz sırasında UV-Vis spektrofotometre kullanılarak izlenmiştir.Article Electrochemical and Optical Properties of an Azo Dye Based Conducting Copolymer(2009) Cihaner, Atilla; Algı, FatihThe electrochemical and optical properties of a novel conducting copolymer called poly(2,5' -dimethyl-[4- (2,5-di-thiophen-2-yl-pyrrol-1-yl)-phenyl]azobenzene-co-(3,4-ethylenedioxythiophene)) (poly(1-co-EDOT)) are reported. Electrochemically synthesized poly(1-co-EDOT) based on the azo dye has a well-defined and reversible redox couple (0.37 V vs. Ag/AgCl) with good cycle stability. The copolymer film exhibits high conductivity (13 S/cm) as well as electrochromic behavior (magenta when neutralized and transmissive sky blue when oxidized). Furthermore, electro-optically active copolymer film has a low band gap of 1.79 eV with a π − π* transition at 555 nm.Article Citation - WoS: 7Citation - Scopus: 9Ann-Assisted Forecasting of Adsorption Efficiency To Remove Heavy Metals(Tubitak Scientific & Technological Research Council Turkey, 2019) Buaısha, Magdi; Balku, Şaziye; Yaman, Şeniz ÖzalpIn wastewater treatment, scientific and practical models utilizing numerical computational techniques suchas artificial neural networks (ANNs) can significantly help to improve the process as a whole through adsorption systems.In the modeling of the adsorption efficiency for heavy metals from wastewater, some kinetic models have been used such as pseudo first-order and second-order. The present work develops an ANN model to forecast the adsorption efficiency of heavy metals such as zinc, nickel, and copper by extracting experimental data from three case studies. To do this, we apply trial-and-error to find the most ideal ANN settings, the efficiency of which is determined by mean square error (MSE) and coefficient of determination (R2). According to the results, the model can forecast adsorption efficiency percent (AE%) with a tangent sigmoid transfer function (tansig) in the hidden layer with 10 neurons and a linear transferfunction (purelin) in the output layer. Furthermore, the Levenberg–Marquardt algorithm is seen to be most ideal for training the algorithm for the case studies, with the lowest MSE and high R2 . In addition, the experimental results and the results predicted by the model with the ANN were found to be highly compatible with each other.Article Synthesis, Properties, and Electrochemistry of a Photochromic Compound Based on Dithienylethene and Prodot(2015) Algı, Melek Pamuk; Cihaner, Atilla; Algı, FatihAbstract: The synthesis, photochromic features, and electrochemistry of a novel material based on dithienylethene (DTE) and 3,3-didecyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine (didecyl-ProDOT) units are described. It is noteworthy that 1,2-bis(5-(3,3-didecyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepin-6-yl)-2-methylthiophen-3-yl)cyclopent-1-ene can be efficiently switched between open and closed states by light in both solution and in the solid poly(methyl metacrylate) (PMMA) matrix. It is also found that the emission of this novel compound can be switched on and off upon irradiation.Article The Synthesis, Characterization and Energy Transfer Efficiency of a Dithienylpyrrole and Bodipy Based Donor-Acceptor System(2009) Atalar, Taner; Cihaner, Atilla; Algı, FatihA dithienylpyrrole-BODIPY based donor-acceptor system with 1,4-phenylene spacer as a model system for energy transfer was designed and synthesized. Absorption and emission spectra have revealed an efficient resonance energy transfer from dithienylpyrrole as donor to BODIPY as acceptor.Article Experimental and Theoretical Investigation of the Reaction Between Co2andcarbon Dioxide Binding Organic Liquids(2016) Tankal, Hilal; Orhan, Özge Yüksel; Alper, Erdoğan; Özdoğan, Telhat; Kayı, HakanThe reaction kinetics of CO2absorption into new carbon dioxide binding organic liquids (CO2BOLs) was com-prehensively studied to evaluate their potential for CO2removal. A stopped- ow apparatus with conductivity detectionwas used to determine the CO2absorption kinetics of novel CO2BOLs composed of DBN (1,5-diazabicyclo[4.3.0]non-5-ene)/1-propanol and TBD (1,5,7-triazabicyclo[4.4.0]dec-5-ene)/1-butanol. A modi ed termolecular reaction mechanismfor the reaction of CO2with CO2BOLs was used to calculate the observed pseudo- rst{order rate constant k0(s1)and second-order reaction rate constant k2(m3/kmol.s). Experiments were performed by varying organic base (DBN orTBD) weight percentage in alcohol medium for a temperature range of 288{308 K. It was found that k0increased withincreasing amine concentration and temperature. By comparing using two different CO2BOL systems, it was observedthat the TBD/1-butanol system has faster reaction kinetics than the DBN/1-propanol system. Finally, experimentaland theoretical activation energies of these CO2BOL systems were obtained and compared. Quantum chemical calcula-tions using spin restricted B3LYP and MP2 methods were utilized to reveal the structural and energetic details of thesingle-step termolecular reaction mechanism.Article Gold-Assembled Silica-Coated Cobalt Nanoparticles as Efficient Magnetic Separation Units and Surface-Enhanced Raman Scattering Substrate Lütfiye Sezen Yildirim1,, Murat Kaya2,∗,, Mürvet Volkan(Tubitak Scientific & Technological Research Council Turkey, 2019) Yıldırım, Lütfiye Sezen; Kaya, Murat; Volkan, MürvetMagnetic and optical bifunctional nanoparticles that combine easy separation, preconcentration, and efficientSERS capabilities have been fabricated with high sensitivity and reproducibility through a low-cost method. Thesegold nanoparticles attached on magnetic silica-coated cobalt nanospheres (Co@SiO2 /AuNPs) display the advantageof strong resonance absorption due to gaps at nanoscale between neighboring metal nanoparticles bringing large fieldenhancements, known as “hot spots”. The prepared particles can be controlled by using an external magnetic field,which makes them very promising candidates in biological applications and Raman spectroscopic analysis of dissolvedorganic species. The magnetic property of the prepared particles lowers the detection limits through preconcentrationwith solid-phase extraction in SERS analysis. The performance of the prepared nanostructures was evaluated as a SERSsubstrate using brilliant cresyl blue (BCB) and rhodamine 6G (R6G) as model compounds. The solid-phase affinityextraction of 4-mercapto benzoic acid (4-MBA) using bifunctional Co@SiO2 /AuNPs nanoparticles followed by magneticseparation and the measurement of the SERS signal on the same magnetic particles without elution were investigated.Approximately 50-fold increase in SERS intensity was achieved through solid-phase extraction of 8.3 × 10 −6 M 4-MBAin 10 min.
