08. İYTE Tezler / IZTECH Theses & Dissertations
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Browsing 08. İYTE Tezler / IZTECH Theses & Dissertations by Author "04.01. Department of Chemistry"
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Master Thesis 3d-Printed Multiprobe Analysis System for Solar Fuel Research; Design, Fabrication and Testing(Izmir Institute of Technology, 2016-12) Harmanlı, İpek; Karabudak, Engin; Ebil, Özgenç; 04.01. Department of Chemistry; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of TechnologyMethods of generating electricity with unlimited, clean and cheap energy from solar energy are tried to be investigated and developed in practical and theoretical academic fields. Especially, photocatalytic water splitting (PWS) systems have been identified as the main method in this study as well as in many studies due to the advantages provided by production of solar fuels from water. In this research, a study was carried out on the alternatives of the both used experimental set-up and used photocatalytic material for PWS systems. A study has been carried out on both the used experimental setup and the used photocatalytic material alternatives in PWS systems. As an alternative experimental setup that allows small volume analysis for PWS by Unisense gas microsensors, a mini photoreactor was designed using 3-D drawing and printing techniques and its usability was tested for PWS applications. Moreover, some characterization results for the electronic band structure and the band gap of the lead (II) trioxovanadate (V) chloride [PbVO3Cl] crystal, which was discovered by Eanes and co-workers in 2007 at IZTECH, was introduced in this study by not only theoretical (DFT approximations; LDA, GGA and HSE06) but also experimental (XRD, Diffuse Reflectance Method- Tauc Plot, Raman Spectroscopy, Four Probe) methods. Also, its estimated theoretical price and its potential for future application in tandem solar fuel device as a photoanode in combination with Si photocathode was calculated and discussed. The results showed that the designed mini photoreactor system is an open to development apparatus that is suitable for PWS, besides, PbVO3Cl has an "indirect transition" band structure and a band energy of ~ 2.2 eV. Although it did not give an effective result in PWS applications done by the designed mini photoreactor, it can be said that it is a semiconductor which is worth studying and developing in detail for other researches in this field due to the compatibility of its band energy amount and optical properties for PWS.Master Thesis Aas, Xrpd, Sem/Eds, and Ftir Studies of the Effect of Calcite and Magnesite on the Uptake of Pb2+ and Zn2+ Ions by Natural Kaolinite and Clinoptilolite(Izmir Institute of Technology, 2005) Zünbül, Banu; Shahwan, Talal; Shahwan, Talal; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of TechnologyIn this study, the effect of magnesite and calcite on the uptake of lead and zinc ions by mixtures of these carbonates with kaolinite and clinoptilolite was investigated at various loadings and mixture compositions. The concentration of both ions in the liquid phase was in measured using AAS, while XRPD, SEM/EDS, and FTIR techniques were used in characterizing the solid samples. Thestudy included the determination of kinetics and sorption isotherms of lead and zinc on pure kaolinite and clinoptilolite. Moreover, the sorption behavior of lead and zincat different concentrations and pH conditions was investigated on mixtures of calcite and magnesite with kaolinite and clinoptilolite at carbonate mass percentage compositions of 5, 10, 25, 60 in addition to pure calcite and magnesite. The morphologies of theformed precipitates, the plausible structural change in the lattice of calcite, magnesite, kaolinite, and clinoptilolite originating from sorption of lead and zinc ions was examined. According to obtained results, the sorption affinity of kaolinite and clinoptilolite towards lead is larger than their affinity towards zinc. Within the operating experimental conditions, the sorption capacity increased with increasing the amountsof calcite, and magnesite. The overall order of retention of lead and zinc was observed as magnesite . calcite> clinoptilolite> kaolinite under neutral and alkaline pH conditions and high loadings. When the initialconcentration of zinc and lead ions is raised to saturation conditions, rapid overgrowth of cerussite and hydrozincite was observed. Increasing the initial pH to 10,0 causedenhancement in the dissolution of calcite and magnesite, leading to the enhancingthe precipitation of hydrozincite, and an increased formation of hydrocerussite instead ofcerussite. The uptake of Zn2+ and Pb2+ions by calcite and magnesite have lead to modifying the geometry of the carbonate groups, the thing reflected as variation in their vibrational bands.Master Thesis The Activity of Silica Immobilized Palladium N-Heterocyclic Carbene Complexes Toward Mizoro-Heck Reaction and Their Characterization(Izmir Institute of Technology, 2005) Aksın, Özge; Artok, Levent; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of TechnologyC-C bond formation reactions are among the important processes in chemistry.A palladium-catalyzed reaction, commonly known as the Mizoroki-Heck (M-H) reaction, is a powerful method in construction of C-C coupling of olefins with aryl and vinyl halides.This thesis describes, mainly development and applications of novel silica anchored saturated molecular Pd-N-heterocyclic carbene (Pd-NHC) catalysts toward the M-H reactions of aryl halides.Characterization of the novel Pd-NHC complexes were performed using elemental analysis, NMR and X-ray crystallography techniques. The synthesized complexes were anchored over an amorphous silica surface through their triethoxy silane groups.On the basis of the results, the silica supported saturated Pd-NHCs were found to be highly active catalyst precursors for Mizoroki-Heck reactions of iodo- and bromoarenes with styrene and butyl acrylate olefins, when reactions were performed at 140 C in the presence of 1.5 molar equivalent Na2CO3 base. The catalyst preserved its original activity for 4-iodoanisole, 4-bromoacetophenone, 4-iodoacetophenone, iodobenzene and 4-iodotoluene reagents at least for 8 uses when Pd concentration, with respect to the aryl halide, was 0.5% in the reaction medium.The higher turnover frequencies were realized at the lower Pd concentrations. The AAS analyses revealed the presence of dissolved Pd species within the reaction medium at the early stages of reaction. Along with this finding, determination of Pd agglomerates onto silica surface by TEM examination indicates that the catalyst acted as a Pd reservoir and reactions were catalyzed homogeneously. In the course of reaction, Pd is liberalized to the solution involved with the reaction cycle and deposited onto silica surface to lead to form less active Pd agglomerates. That no trace of dissolved Pd was detected at the end of reaction by AAS is a positive finding for the purity of product.Master Thesis Acylation of 2-Methoxynaphthalene Over Ion-Exchanged Beta Zeolite(Izmir Institute of Technology, 2002) Kantarlı, İsmail Cem; Artok, Levent; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of TechnologyFriedel Crafts acylation of 2-Methoxynaphthalene was carried out over various ion-exchanged . zeolites (Mn+., where Mn+: In3+, Zn2+, Al3+, Fe3+, La3+) with various anhydride (acetic, propionic and benzoic anhydrides), or acyl chloride (acetyl, propionyl and benzoyl chlorides) acylating reagents. The results suggested that selectivity towards the 6-substituted products was higher with the larger size anhydrides, propionic and benzoic anhydrides. The metal cation type within the zeolite significantly influenced the extent of conversion and product distribution. That La3+ exchanged zeolite displayed higher selectivity for the 6-position acylated product with anhydrides ascribed mainly to narrowing of channels by the presence of La(OH)2+ ions that leave no room for the formation of more bulky isomeric forms and to enhanced Bronsted acidity of the zeolite. With acyl chlorides, the recovery of ketone products was found to be remarkably low. 1-Acyl-2-methoxynaphthalenes actively underwent deacylation when acyl chlorides were used as the acylation reagent.Master Thesis Alkenil Epoksitlerin Organoboronlar ile Tepkimelerinin Mekanistik ve Stereokimyasal Çalışmaları ve Ürün Uygulamaları(2024) Ekiyorum, Gamze; Artok, Levent; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of TechnologyAllilik bileşiklerin uygun ayrılan gruplarla 1,3-substitüsyon reaksiyonları, aril gibi fonksiyonel gruplara sahip alkenil reaktiflerin sentezi açısından organik kimyada temel bir öneme sahiptir. Bu reaksiyonlar genellikle metal katalizörler gerektirir ve farklı substratlar üzerinde regio- ve stereoselektiflik elde etmek önemli bir zorlu süreç olmaya devam etmektedir. Alkenil epoksitler de, allilik elektrofilller olarak, 1,3-substitüsyon tepkimeleri vererek da fonksiyonel allilik alkoller üretebilmektedir.Alkenil epoksitlerin kullanımının önemli bir avantajı, substitüsyon sırasında epoksit halkasının açılmasıyla hidroksil gruplarının oluşması ve allilik alkollerin üretilmesidir. Bu allilik alkoller, organik sentezde önemli ara ürünlerdir. Organoboronlar, aril gruplarının eklenmesi veya alkenilasyon reaksiyonları için birçok çapraz bağlama yönteminde yaygın olarak kullanılmakta olup, çeşitli allilik reaktiflerle çapraz bağlama reaksiyonlarında da kullanılmaktadır. Mevcut çalışmalar organoboronların terminal alkenil epoksitlerle olan reaksiyonlarını incelemiş olurken, literatürde iç alkenil epoksitler için seçimli ve başarılı metodolojilerin eksikliği göze çarpmaktadır.Laboratuvarımız, organoboronlarla iç alkenil epoksitlerin paladyum katalizli reaksiyonlarının, alkenil epoksitin C1 pozisyonunda bir hidroksil grubu içermesi durumunda regio- ve stereoselektif bir şekilde ilerleyerek aril-substitüe alilik alkoller elde edilebileceğini yakın zamanda göstermiştir. Bu yöntem, Pd⁰-AsPh₃ kombinasyonunu kullanmakta ve hafif koşullar altında uygulanmaktadır.Bununla birlikte, önceki çalışmalarda ayrıntılı deneysel veriler veya mekanistik öngörüler rapor edilmemiştir. Bu nedenle, bu tezin temel amacı, ürünlerin bağıl stereomerik yapısını aydınlatmak ve daha kapsamlı deneysel veriler sağlamaktır. Ayrıca, bu metodolojinin doğal olarak oluşan bileşiklerin sentezindeki potansiyel uygulamaları da tartışılmaktadır.Master Thesis Antiproliferative and Anticancerogenic Effects of 5-Asa and Its Novel Synthesized Oligomer(Izmir Institute of Technology, 2017-07) Atahanova, Hurshida; Şanlı Mohamed, Gülşah; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of TechnologyIn the world, colorectal cancer (CRC) is third common malignant diseases and fourth leading cause of cancer-related death. More recently, epidemiological studies have suggested that regular intake of 5-aminosalicylic acid (5-ASA), the drug used in treatment of inflammatory bowel disease (IBD), reduces the risk of CRC developing in patients with ulcerative colitis. Several action mechanisms of 5-ASA are proposed which are independent from its weak cyclooxygenase (COX) inhibitory property, found overexpressed in many cancer types. Lately, polymeric prodrugs developed which contain bioactive unit and have prolonged activity by sustained release, consequently reduced toxicity. However, large molecular weight and long chain can be challenging in penetrating into the cell membrane. Thus, oligomers with shorter chain of monomer units and lower molecular weight can be preferred choice. In the present study we evaluated antiprolifertaive and anticancerogenic effect of novel synthesized 5-ASA based oligomer compared to its active monomer, 5-ASA in Caco-2, DLD-1, HeLa and CCD-18Co cells. According to MTT, apoptotic rate, cell cycle phase distribution and scratch assay analysis the oligomer showed higher activity compared to its monomer, 5- ASA at lower doses. The oligomer induced cell death and cell cycle arrest in colorectal cancer cells and in HeLa cells. However, no significant induced cell death and cell cycle arrest observed in normal human colon cells, CCD-18Co when exposed to 5-ASA and the oligomer. Overall results indicate that the oligomer can be promising candidate for prodrugs in treatment and prevention of colorectal cancer.Master Thesis Antiproliferative Properties of 2'-alkoxymethyl Substituted Klavuzon Derivatives(Izmir Institute of Technology, 2017) Yıldız, Mehmet Salih; Pesen Okvur, Devrim; Çağır, Ali; Çağır, Ali; Pesen Okvur, Devrim; 04.03. Department of Molecular Biology and Genetics; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of TechnologyOne of the main objectives of studies on anticancer agents is that the agent is expected to show a high cytotoxic activity on cancer cells and show a less cytotoxic effect on the contrary in healthy cells or never show cytotoxic activity. (R)- goniothalamin, isolated from the Goniothalamus plant, is a styryl lactone and has been found to have a selective antiproliferative property on cancer cells in studies conducted. The Michael acceptor feature in the structure of goniothalamin is thought to be covalently bonded to the nucleophilic side chains of the enzymes and show activity in this way. In previous studies, it has been shown that 1-naphthyl substituted 5,6-dihydro- 2H-pyran-2-one derivatives and 4'-methyl klavuzon derivatives exhibit higher cytotoxic activity on cancer cells than goniothalamin. In this study, antiproliferative properties of newly synthesized 2'-alkoxymethyl substituted klavuzon derivatives have been examined and MIA PaCa-2 pancreatic cancer cell lines and HPDEC pancreatic healthy cell lines were used. MTT cell viability tests were performed at the first step of this study. As a result of this study, it has been observed that the 2'-isobutoxymethylklavuzon derivative has selective cytotoxic activity on the MIA PaCa-2 cell line. It showed activity at lower concentrations than goniothalamin. Cytotoxic activities of the compounds are associated with the size of the R group at position 2’-. Methoxymethyl substituted the worst selective activity among these compounds whereas isobutoxy derivative the best selective one. In the second stage of the study, the inhibition on topoisomerase I enzyme was studied. The 2'-alkoxymethyl klavuzon derivatives were found to have Topo I enzyme inhibition properties depending on concentration and time manner. The study continued with choices methoxy and isobutoxy derivatives and these two compounds caused an arrest at G1 phase and DNA damage. Also, isobutoxy derivative induced apoptosis in the MIA PaCa-2 pancreatic cancer cell lines.Master Thesis Asymmetric Synthesis and Anti-Tumor Properties of Conformationally Constrained Analogues of (s)-And (r)-Goniothalamin(Izmir Institute of Technology, 2008) Kasaplar, Pınar; Çağır, Ali; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of TechnologyNaturally isolated 5-substituted-a,B-unsaturated-.-lactones gained great attention of researchers due to their cytotoxic and anti-tumor properties. Styryl lactones are the most interesting members of this group of naturally available compounds. One of the well-known and important example for styryl lactone is goniothalamin, which shows cytotoxicity against variety of cancer cell lines. This cytotoxic property was shown to be selective for cancer cell lines with no significant cytotoxicity toward non-malignant cells. Recent structure activity relationship (SAR) studies on goniothalamin shows that R configuration on its stereogenic center, trans double bonded linker and Michael acceptor parts of the molecules are essential for its cytotoxic activity. In this study conformationally constrained analogues of (S)- and (R)-goniothalamin were synthesized. Syntheses were started with the catalytic asymmetric allylation of benzaldehyde, naphthaldehyde and quinaldehyde derivatives in the first step, then formed alcohols were acrylated with acryloyl chloride to yield the corresponding esters, in the last step, ring closing metathesis with Grubbs. catalyst yielded the target molecules. Meanwhile, in this study the synthesized 5-aryl-substituted-a,B-unsaturated-S-lactones were tested to determine their cytotoxicity against MCF-7, PC-3, DU-145 and LNCAP cancer cell lines.Doctoral Thesis Asymmetric Synthesis of 5,6-Dihydro Derivatives(Izmir Institute of Technology, 2014-09) Akçok, İsmail; Çağır, Ali; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technologyα,β-unsaturated lactone derivatives are very important structural core which are isolated from nature and shown as source for several biological activities. Biologically active styryl δ-lactones are well known α,β-unsaturated-δ-lactones. Up to date, many α,β- unsaturated-δ-lactones and their analogues have been isolated and synthesized, exhibiting promising anti-proliferative properties against different cancer cell lines. In this thesis, large scale asymmetric syntheses of (R)-4’-methylklavuzon and (R)- 2’-methylklavuzon were completed successfully. Also, syntheses of heteroatom functionalized naphthyl substituted novel α,β-unsaturated-δ-lactone (5,6-dihydro-2Hpyran- 2-one) derivatives, α,β-unsaturated-γ-lactone (furan-2(5H)-one) derivatives and 7- membered α,β-unsaturated lactone (6,7-dihydro-5H-oxepin-2-one) derivatives were accomplished. Development of a method for one-pot synthesis of 6-membered α,β-unsaturated- δ-lactone was also studied, and a new vinylogous aldol addition method was developed. By this method, new α,β-unsaturated methyl esters were prepared via dienolate formation starting with methyl buten-3-oate.Master Thesis Biosorption of Aqueus Pb2+, Cd2+, and Ni2+ Ions by Dunaliella Salina, Oocystis Sp., Porphyridium Cruentum, and Scenedesmus Protuberans Prior To Atomic Spectrometric Determination(Izmir Institute of Technology, 2008) Karaca, Meral; Eroğlu, Ahmet Emin; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of TechnologyIn this study, the possibility of using four different algae for the sorption of heavy metals, namely, Pb, Cd, and Ni, from waters was investigated. Dunaliella salina, Oocystis sp., Porphyridium cruentum, and Scenedesmus protuberans were shown to be good candidates for the sorption/removal of the metals from waters prior to atomic spectrometric determination. Characterization of the algae was carried out by scanning electron microscopy, FTIR, elemental analysis, and thermogravimetric analysis.All biomasses behaved similarly in the optimization of sorption parameters.Solution pH of 6.0, sorbent amount of 10.0 mg for 10.0 mL sample volume, shaking time of 60 min, and reaction temperature of 25C were used in the sorption experiments. It was demonstrated that the primary sorption mechanism is the electrostatic attraction between the negatively charged functional groups on the surface of the biomass and the positively (+2) charged metal ions in the solution. Among the biomasses investigated, Dunaliella salina has shown the highest sorption capacity for all the metal ions. It was followed by Oocystis sp., Scenedesmus protuberans and Porphyridium cruentum. Additionally, the biomasses examined have demonstrated the highest affinity towards Pb2+ which was followed by Cd2+ and Ni2+.The competitive biosorption experiments have shown that the uptake of Pb2+ ions was not influenced by the presence of other ions for all the algae studied.However, the general trend for the other biomasses was a decrease in their sorption efficiency towards Cd2+ and Ni2+ ions with the increase in the concentration of the competitive ions.It can be proposed that the algal biomasses investigated in this study can be utilized successfully in the sorption and selective removal of the studied heavy metal ions from waters.Master Thesis Borylation of Petroleum Cracking Olefin Products(01. Izmir Institute of Technology, 2022-12) Arapoğlu, Mehmet Anıl; Artok, Levent; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of TechnologyCracking is a process that long-chain hydrocarbons are broken down into more valuable fragments called naphtha cracking products. The olefins formed as a result of this process have various functions such as forming the smallest building blocks of fine and speciality chemicals. It has been foreseen that borylation processes can be applied as a conversion method of these products into valuable intermediate structures. In this context, this thesis describes first time the transition-metal-catalyzed borylation of a number of petroleum cracking olefin products. Borylation reactions have been extensively investigated in the literature and have become one of the popular methods for synthesizing organoboron reagents, which can also be used in the synthesis of functional materials, pharmaceuticals, and agricultural chemicals. In the context of this thesis, petroleum cracking olefinic products were converted into high-value-added organoboron derivatives by metal-catalysed hydroboration and dehydrogenative borylation methods. For this purpose, the experimental conditions were optimized using propene and isobutene reagents. It has been shown in this study that iridium complexes with N-Heterocarbene (NHC) ligands are highly effective catalysts and therefore anti-Markovnikov hydroboration products can be produced in excellent yields even at very low catalyst loadings. On the other hand, alkenyl boron products could be obtained with high yields, which could be performed in the absence of dehydrogenative borylation reactions, ligand, base, and any other additives. The applicability of these methods in internal and terminal alkenes such as cyclohexene, ethene, decene and styrene has been also demonstrated. Finally, these products were converted into a number of intermediates by Suzuki-Miyaura cross-coupling reactions. Thus, in the conversion of alkenes to valuable intermediates, practical and sustainable applications would be possible by using simple, abundant, and cheap reagents instead of expensive and dangerous chemicals.Master Thesis Changes in Protein Profiles in Bortezomib Applied Multiple Myeloma Cells(Izmir Institute of Technology, 2011) Turan, Taylan; Şanlı Mohamed, Gülşah; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of TechnologyMultiple Myeloma is a malignant B-cell neoplasm that is characterized by the accumulation of malignant plasma cells in the bone marrow. Over the recent years, several novel agents have been introduced in the treatment of this disease. Bortezomib is the first of a new class of agents known as proteasome inhibitors. The main objective of the project was basically to both determine the cytotoxic and apoptotic effects of Bortezomib on Multiple Myeloma U-266 cells and compare and explore the differences between Bortezomib applied Multiple Myeloma cells and control group Multiple Myeloma cells, by proteomics studies. In order to achieve our aims in the project, variety of multidisciplinary subjects were come together. Cancer research techniques, biochemical studies at protein level and proteomics were combined in our studies. In this study, our experimental results demonstrated that Bortezomib has antiproliferative and apoptotic effects on MM U-266 cells. On the other hand, the responsible proteins for the effect mechanism of anti-cancer agent on cells were determined by MALDI-TOF-TOF Mass Spectrometry for the first time. According to the mass spectrometric analysis, 37 protein spots were differentially expressed. Among them, five proteins were newly formed, ten proteins lost, twelve proteins were up-regulated and ten proteins were down-regulated as compared to control group (untreated cells).These differential expressed proteins in response to Bortezomib have different important functions ranging from cell signaling transduction, cell cycle regulation, apoptosis to immunity and defense mechanism. In conclusion, it was identified which proteins have a central role behind the effect of Bortezomib on MM U-266 cells. The identified proteins may let to be possible to treat other cancer types by same anticancer agent. The data obtained by this study may also be helpful for medical schools and drug designers and may also provide new treatments.Doctoral Thesis Characterization and Catalytic Applications of Hydrothermally Synthesized Poyoxotungstate Clusters Containing Organic-Inorganic Hybrid Materials(Izmir Institute of Technology, 2019-07) Ece, Özlem; Eanes, Mehtap; Çağır, Ali; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of TechnologyMany scientists have been interested in hydrothermal synthesis and characterization of polyoxometalate clusters containing organic-inorganic hybrid materials recently because of having different applications in lots of fields, especially, using as catalysis in chemical reactions. In this study, three novel polyoxotungstate clusters were synthesized using hydrothermal method and catalytic activities of these three novel polyoxometalates and in addition two crystals previously synthesized in our group were studied. The first compound, [(4,4’-bpyH2)3][PCuW11O39] yellow crystals, crystallize in the space group P2(1)/n of the monoclinic system with four formula units in a cell. The crystal is a Keggin polyoxometalate and includes free 4,4’-bipyridine groups between the clusters. The second compound, (4,4’-bpyH2)[H2PW12O40]2.H2O colorless crystals, crystallize in the space group Ia-3 of the cubic system with twelve formula units in a cell. The crystal is a Keggin polyoxometalate and consists of two polyoxotungstate clusters, a free 4,4’-bipyridine group and a water molecule. The third and the last novel compound, (4,4’-bpyH2)4[H2P2W18O62]2 dark yellow crystals, crystallize in the space group P-1 of the triclinic system with four formula units in a cell. The crystal is a Wells-Dawson polyoxometalate and contains two polyoxotungstate clusters and free 4,4’-bipyridine groups between clusters. The catalytic study has been carried out using starch hydrolysis reactions by using hydrothermal synthesis and five different crystals were tried and conversion results were obtained. Starch samples converted to D-glucose with glucose yields above 90 wt.%. Catalyst reusability was performed for each crystal. No appreciable loss was observed in activity after five reaction cycles for each crystal.Master Thesis Characterization and Corrosion Performance of Γ-Glycidoxyropyltrimethoxsilane Modified Epoxy Polymer(Izmir Institute of Technology, 2010) Oturaklı, Şafak; Polat, Hürriyet; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of TechnologyEpoxy polymers have been widely used in a protective coating and adhesive due to its strong adhesion, high chemical resistance, and good processing characterisitics. However; epoxy coatings absorbs moisture easily, and the diffusion of absorbed water into the epoxy.steel interface weakens the interfacial adhesion strength between epoxy and steel in corrosive enviroment, due to the presence of hydrophilic hydroxy group in the cured network (epoxy/amine reaction). In this study, commercial epoxy polymer was chemically modified by γ-glycidoxypropyltrimethoxysilane monomer under the catalysis organotin compound via the reaction between hydroxyl group in epoxy polymer and alkoxy group in silanes, aiming to enhance the corrosion performans of epoxy polymer. Commercial epoxy polymer and silane modifed epoxy polymer were characterized by NMR spectroscopy, FTIR spectroscopy, epoxy equivalent weight measurement, contact angle measurement, surface energy measurement, hardness test and MEK double-rub test. The results showed that γ-glycidoxypropyltrimethoxysilane has been successfully grafted to epoxy polymer. Corrosion performance was evaluated by salt spray test acording to ASTM B117. The results showed that the chemically modified epoxy coating perform an improvement in resistance againts the penetration of water in polymeric resin and beter protectiveness on metalic corrosion.Doctoral Thesis Characterization of Conjugated Polyelectrolytes for Nucleic Acid Sensing, Gene Delivery and Imaging(01. Izmir Institute of Technology, 2022) Yücel, Müge; Yıldız, Ümit Hakan; Yıldız, Ümit Hakan; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of TechnologyIn this thesis, cationic derivatives of poly(3-alkylmethoxythiophene) (PT) which are a class of conjugated polyelectrolytes (CPE), have been synthesized. PT has been polymerized via FeCl3 oxidative polymerization, were treated in a set of solvents to elaborate coil conformation of polymer chain in different physicochemical environment. Spectroscopic and scattering techniques have ascertained that ethylene glycol is a good solvent for PT regarding Flory-Huggins theory. The smaller interaction parameter of PT with respect to ethylene glycol than water drives a thermodynamically driven ultra-small particle (Pdot) formation in aqueous phase by a rapid nanophase separation between PTrich ethylene glycol and PT-poor water phase. All CPEs have been then employed to prepare single polymer chain polymer dots (Pdot) by “nanophase separation” method. As a next step, Pdots have been characterized in terms of optical and colloidal properties that they possess in the backbone conformations altered by solvation effect. Regarding their colloidal characteristic, translocation of Pdot into cancerous cells was analyzed compared to healthy cells by 2D cell culture and co-culture studies. It has reported that Pdots have ability to penetrate through nuclear envelope in hepatocellular carcinoma whereas accumulate around nucleus of healthy liver cells in cytoplasm. Additionally, Pdots were studied in breast cancer cell lines to understand the behavior of Pdot staining in 2D cell culture of invasive and non-invasive breast cancer types. The findings suggest that Pdots are prone to penetrate into the invasive cancerous cells attributed to the greater deformations on nucleus membrane of triple negative breast cancer cells. In a next application, the enhanced photophysical property of PT exhibited in ethylene glycol media allows PT to be utilized as a fluorescent probe for determination of single nucleotide polymorphism by a non-amplification-based protocol. Fluorescence emission at specific wavelengths resulted from very distinct conformations of PT chain is the key elements for the SNP detection assay. The evaluation of optical data obtained from the probe with principal component analysis proves the separation of healthy individuals from patients with an overall 96% accuracy.Master Thesis Characterization of Ion Implanted Surfaces by Laser Induced Breakdown Spectroscopy, Libs(01. Izmir Institute of Technology, 2008) Örer, Sabiha; Yalçın, Şerife; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of TechnologyLaser Induced Breakdown Spectroscopy, LIBS, is a versatile atomic emission spectrometric technique for the determination of the elemental composition of solids, liquids, gases and aerosols with the need for little or no sample preparation.In this study, an optical LIBS system from its conventional parts was designed, constructed and optimized for spectrochemical analysis of solid materials. Specifically, the 2-D elemental distribution of Ge ions on silicon oxide surfaces, prepared by the method of ion implantation, with differing atomic concentrations between 1016 - 1017 ions/cm2 have been investigated by LIBS. For this purpose a Nd: YAG laser operating at the second harmonic wavelength, 532 nm, was used to create a plasma on the material surfaces. Spatially and temporally resolved atomic emission from the luminous plasma was detected by an Echelle spectroctrograph and Intensified Charged Coupled Device (ICCD) detector combination. Spectral emission intensity from the LIBS measurements has been optimized with respect to time, crater size, ablation depth and laser energy. Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) coupled with Energy Dispersive X-Ray Spectroscopy (EDX) have been utilized to obtain crater depth, morphology and elemental composition of the sample material, respectively. LIBS spectral data revealed the possibility of performing 2-D distribution analysis of Ge ions over the silicon oxide substrate at Ge ion concentrations lower than 0.5% (atomic). LIBS as a fast semi-quantitative analysis method with 50.m lateral and 800 nm depth resolutions has been evaluated. In this wok, elemental analysis of some metal surfaces, such as Al and Cu, was also performed by LIBS.Keywords: LIBS, surface analysis, Ge ion implantation, lateral resolution,Master Thesis Characterization of the Adsorption Behaviour of Aqueous Cd (ii) and Ni (ii) Ions on Nanoparticles of Zero-Valent Iron(Izmir Institute of Technology, 2008) Efecan, Nazlı; Shahwan, Talal; Shahwan, Talal; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of TechnologyIron nanotechnology is recently concieved as a promising tool in environmental remediation. By virtue of their high surface/volume ratio, iron nanoparticles were shown to demonstrate outstanding sequestration capacity for various organic and inorganic pollutants.In this work iron nanoparticles were synthesized using the borohydride-reduction method. The obtained material showed chain like morphology, with the diameter of the nanoparticles being with in 20-80 nm range. HR-TEM images showed that the nanoparticles have a core-shell structure, with the core containing iron in its zero-valent state, while the shell is composed of iron oxides (Fe2O3, Fe3O4, FeOOH)and is generally < 3 nm in thickness.Nano-sized zero valent iron (nZVI) was then tested as a sorbent material for aqueous Cd2+ and Ni2+ ions. The uptake of these ions was investigated under various experimental conditions like time, concentration, pH, repititive application, and liquid/solid ratios. In addition, the uptake of these ions was compared with that of Cu2+, Zn2+, and Sr2+ in order to assess the effect of the reduction potential on the extent of removal.The results showed that nZVI is a very effective sorbent in terms of both kinetics and capacity of removal of the ions. Under the investigated conditions, the uptake reached equilibrium in less than one hour of contact time. Up to the initial concentration of 500 mg/L, the ions were removed almost completely utilizing an nZVI amount of 0.025 g and a solution volume of 10 ml. According to XRD and XPS results, both of Cd2+ and Ni2+ ions were fixed by nZVI through a non-reductive mechanism, that seems to be dominated by interaction of these ions with the exposed iron oxyhydroxide groups at the interface with the solution.Master Thesis Chitosan-Plasmid Dna Nanoparticles: Cytotoxic and Cytostatic Effects on Human Cell Lines(Izmir Institute of Technology, 2015-12) Bor, Gizem; Şanlı Mohamed, Gülşah; Demir, Mustafa Muammer; 03.09. Department of Materials Science and Engineering; 04.01. Department of Chemistry; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of TechnologyAlthough chitosan nanoparticles (CNs) became a promising tool for several biological and medical applications owing to their inherent biocompatibility and biodegrability, studies regarding their effects on cytotoxicity and cytostatic properties still remain insufficient. Therefore, in the present study, we decided to perform comprehensive analysis of the interactions between CNs – pKindling-Red-Mito (pDNA) and different cell line models derived from blood system and human solid tissues cancers. The resulting CNs-pDNA was investigated with regard to their physical-chemical properties, cellular uptake and transfection efficiency, cytotoxic and cytostatic properties. The nanoparticles showed high encapsulation efficiency and physical stability even after 2 days for various formulations. Moreover, high gene expression levels were observed already 96 h after transfection. CNs-pDNA treatment, despite the absence of oxidative stress induction, caused cell cycle arrest in G0/G1 phase and as consequence led to premature senescence, which turned out to be both, p21-dependent and p21-independent. Also, observed DNMT2 upregulation may suggest the activation of different pathways protecting from the resulting CNs-mediated stress. In conclusion, treatment of different cell lines with CNs-pDNA showed that their biocompatibility was limited and effects were cell type-dependent.Master Thesis Chromatographic Determination of Glycoalkaloids in Eggplant(Izmir Institute of Technology, 2006) Tek, Neslihan; Tek, Neslihan; Eanes, Ritchie C.; 04.03. Department of Molecular Biology and Genetics; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of TechnologyNovel modifications were applied to high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS) for the separation and quantitation of the steroidal glycoalkaloids (SGAs) solanine, chaconine, solamargine, and solasonine as well as the steroidal glycoalkaloid aglycones (SGAAs) solasodine and solanidine. Because attempts to develop a gradient elution HPLC method were only marginally successfully and non-robust, it was deemed more practical to develop separate HPLC methods for either the SGAs or SGAAs of interest. Furthermore, a novel approach using methanol as a mobile phase modifier was still required to successfully separate solamargine and chaconine. Comparing potential mobile phase buffers, ammonium dihydrogen phosphate was chosen as the most efficient, stable, and economical. Separations were best realized isocratically at a column temperature of 50 °C for the SGAs and either 26 °C or 50 °C for the SGAAs. Progesterone was applied as an internal standard. Effects of pH were also tested. Figures of merit such as limit of detection (LOD), limit of quantitation (LOQ), and linear dynamic range are described herein. Lastly, solid-phase microextraction (SPME) using on-fiber derivatization coupled with GC-MS was investigated for extraction and analysis of these SGAAs. A carbowax divinylbenzene (CW-DVB) coated SPME fiber was the most suitable. Solanidine could be extracted and identified directly using our SPME/GC-MS method while solasodine required a derivatization step involving trimethylsilylimidazole (TMSI). Although initial attempts were qualitatively reproducible, eventual degradation to fibers precluded complete study. Cholesterol as an internal standard was investigated.Master Thesis Cloning and Purification of Biosynthetic Enzymes(Izmir Institute of Technology, 2016-12) Gürelme, Ebru; Sürmeli, Nur Başak; Şanlı Mohamed, Gülşah; 03.01. Department of Bioengineering; 04.01. Department of Chemistry; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of TechnologyBioproducts have become prominent with their sustainable, eco-friendly and renewable features. In recent years, research and development studies focused on production of biodiesel and pharmaceuticals. Biodiesel can be synthesized in the form of fatty acid ethyl ester (FAEE) by in vivo activity. This synthesis is catalyzed by wax ester synthases (WS). This study aims cloning and purification of wax ester synthases from Psychrobacter arcticus 273-4 (PaWES) and Mus musculus C57BL/6 (MmWES). PaWES was cloned and expressed by Escherichia coli BL21(DE3) strain, at the proper conditions with using pET expression system. It was purified with approximately 1 mg yield. Cloning of the second wax ester synthase (MmWES) was achieved to Saccha-romyces cerevisiae and it was purified with lower than 1 mg yield. The other aim of this study is related to taxadien-5α-ol-O-acetyltransferase from Taxus cuspidata (TcT5AT). This enzyme belongs to the biosynthesis pathway of Taxol, which is the most commonly used chemotherapy drug. Cloning and purification studies of this enzyme were successfully performed. It was expressed by Escherichia coli BL21(DE3) Star strain and purified with the yield of 23 mg. Immobilized Metal Affinity Chromatog-raphy (IMAC) is used for all three enzymes as a purification strategy. This project can pave the way for structural studies of all biosynthetic enzymes mentioned above. In summary, the findings of this study will circuitously help for solving the relationship between function and structure of these enzymes. It may lead to increased generation of Taxol and FAEE based biodiesel.