Master Degree / Yüksek Lisans Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/11147/3008

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Author: search.filters.author.Çakıcıoğlu Özkan, Seher FehimePublisher: search.filters.publisher.Izmir Institute of Technology

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Now showing 1 - 5 of 5
  • Master Thesis
    Synthesis of Ni and Zn Based Organic Frameworks as Photocatalyst
    (Izmir Institute of Technology, 2019) Dikmen, Merve; Özkan, Seher Fehime; Çakıcıoğlu Özkan, Seher Fehime; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Nickel (Ni) and zinc (Zn) based organic frameworks were synthesized on the synthetic zeolite (5A and 13X), natural zeolite mineral clinoptilolite, -Alumina. Initially the zeolite surface was modified or seeded with metal organic framework (MOF). MOF-zeolite composite materials were characterized with XRD, SEM and ATR-IR to understand whether surface processes was achieved successfully or not. Additionally, band gap energies were evaluated to understand these composite materials were used as photocatalyst. Surface modification with APTES was not affect surface of the zeolites. In spite of that seeding created a layer on the surface of zeolite. Nickel based organic framework was coated onto the surface of modified 5A surface. Hydrothermal ZIF8 (ZIF8(1)) and solvothermal ZIF8 (ZIF8(2)) were synthesized successfully as MOF crystals. Besides ZIF8(2) was coated onto the surface of natural zeolite. Additionally, ZIF8/CuBTC sample were synthesized, seeded and coated onto the surface of natural zeolite. Band gap energies of the MOFs and composite materials were calculated with Tauc plot. Results showed that UV light can be used as light source for photocatalytic reactions of these photocatalysts. Also increasing photocatalyst amount increased dye degredation under UV light.
  • Master Thesis
    Deposition of Cu-Btc on Pulp and Textile Fibers for Sensor Application
    (Izmir Institute of Technology, 2018) Güner, Cemal; Özkan, Seher Fehime; Çakıcıoğlu Özkan, Seher Fehime; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Cu-BTC is synthesized from Copper(II) nitrate and benzene-1,3,5-tricarboxylic acid and it is one of the most common metal organic framework which is used for catalysis, sensing, controlled release, separation and storage processes. The application areas of Cu-BTC could be increased by deposition on different surfaces. Cu-BTC is positively charged and to deposit Cu-BTC on a surface, the surface must have negative charge. The most common natural material with negative charge is cellulose. Raw pulp fibers, cotton and viscose fabrics are rich in terms of cellulose, so they were used as cellulose source. The aim in this study is to deposit Cu-BTC on pulp fibers, cotton and viscose fabrics and then, to investigate their sensing properties. In order to investigate whether Cu-BTC was deposited on cotton, pulp, and viscous fibers or not, a characterization study was carried out to investigate their properties. In this context, XRD, SEM, FT-IR, ATR-IR analysis were performed. As a result of the characterization study, it was concluded that the Cu-BTC was deposited on the pulp, cotton fibers, and viscous successfully. The Cu-BTC deposited substrates showed sensing activity against humidity and NH3 gas.
  • Master Thesis
    Adsorption Kinetics of Methane Reformer Off-Gases on Aluminum Based Metal-Organic Frameworks
    (Izmir Institute of Technology, 2017) Angı, Deniz; Özkan, Seher Fehime; Çakıcıoğlu Özkan, Seher Fehime; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Over the last decades, with the development in industrialization, the combustion of fossil fuels has generated an increasing level of emission of greenhouse gases into atmosphere. Considerable efforts have been endeavored to advance alternative cleaner energy source to relieve the stress on environmental concerns and depletion of oil reserves. Hydrogen is regarded as an ideal clean energy carrier. A great majority of ultrapure hydrogen is produced by hydrogen rich steam methane reformer (SMR) off-gas mainly composed of 60-80% H2, 15-25% CO2, 3-6% CH4 and 1-3% CO, which severely requires an efficient separation and purification process associated with gas adsorption principle. A novel class of porous adsorbents known as metal-organic frameworks (MOFs) represent outstanding separation performance due to possessing large surface area and tunable pore size. Aluminum based metal organic frameworks (Al-TPA) are widely utilized in gas separation/purification applications due to its breathing characteristics by adjusting cell volume reversibly. The highest surface area of Al-TPA was found to be 1270 m2/g by performing solvothermal synthesis route. Diffusion studies of SMR off-gas components on the Al-TPA were carried out at different flow rates (80, 168 and 175 mL/min), temperatures (34, 70 and 100 °C) and concentrations (15 and 28%). High value of parameter L demonstrated that system was under kinetic control. The diffusivity values were found to be ranging from 5.73 x 10-13-8.04 x 10-13 for CO2, 5.03 x 10-13-6.64 x 10-13 for CH4, 1.36 x 10-12-1.56 x 10-12 for H2 and 1.01 x 10-13- 5.03 x 10-13 m2/g for CO respectively with increasing temperature.
  • Master Thesis
    Adsorption of Methane Reformer Off-Gas Components in a Column Packed With Cu, Al,ti and Zn Based Organic Frameworks
    (Izmir Institute of Technology, 2016) Kanaltı, Gaye; Özkan, Seher Fehime; Çakıcıoğlu Özkan, Seher Fehime; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Within the past decade, CO2 emissions from fossil fueled power plants has accelerated rapidly as a result of the increase in energy consumption associated with industrial development all over the world. Beyond the necessity of reduction in CO2 emissions, concerning on the crude oil reserves depletion induced the urgent need of transition to more efficient, renewable, cleaner and cheaper fuel, hydrogen. In the world, most of the hydrogen is produced by hydrogen-rich stream methane reformer (SMR) off gas streams composed of 80-60% H2, 15-25% CO2, 3-6% CH4 and 1-3% CO, thereby separation of SMR components became more of an issue. In this study, adsorption based separation of SMR components were investigated in a column packed with copper (CuTPA, (SLang: 776 m2g-1)), aluminum (AlTPA, (SLang: 1330 m2g-1)), titanium (TiTPA, (SLang: 1835 m2g-1)) and zinc (ZnTPA, (SLang: 1023 m2g-1)) based organic frameworks (MOFs). The pure gas adsorption studies on equimolar CO2/H2, CH4/H2 and CO/H2 systems and the equimolar mixture of CO2/CH4 system were carried out and the experimental breakthrough curves were obtained at three different feed flow rates (10, 20 and 30 mL/min) at three column pressure (1, 5 and 10 bar) at 303 K. The highest adsorption capacities of all MOFs were achieved at 30 mL/min of feed rate and 10 bar operating pressure, at these conditions the non-adsorptive behavior of hydrogen on the aforementioned MOFs was ensured. The amounts of CO2 adsorbed were calculated as 1.61, 5.54, 5.20 and 2.11 mmolCO2/g, while adsorbed CH4 amounts were 1.50, 3.16, 3.25 and 1.90 mmol CH4/g and the adsorbed CO amounts were 1.47, 2.59, 1.91 and 1.83 mmol CO/g on CuTPA, AlTPA, TiTPA and ZnTPA, respectively. The highest selectivity for CO2 over CH4 was attained on TiTPA as 8.0 at 10 mL/min feed rate of CO2/CH4 mixture at atmospheric column pressure and 303 K. The experimental adsorption isotherms of SMR components were fitted well with Langmuir and virial models and the best fitted model parameters were evaluated for each MOF.
  • Master Thesis
    Preparation and Characterization of Tyrosinase Immobilized Gelatin Films
    (Izmir Institute of Technology, 2015) Tetik, İlkin; Şanlı Mohamed, Gülşah; Özkan, Seher Fehime; Çakıcıoğlu Özkan, Seher Fehime; Şanlı Mohamed, Gülşah; 03.02. Department of Chemical Engineering; 04.01. Department of Chemistry; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of Technology
    In this work, tyrosinase enyzme was immobilized on gelatin films by using entrapment and adsorption. In entrapment method, glutaraldehyde was used to crosslink the gelatin matrix. Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), contact angle were used for characterization of the films; UV spectrophotometer was used for measurement of the catalytic activity of the tyrosinase immobilized films in catechol oxidation reaction. The pH and temperature, enyzme and substrate concentration effects on the activity of enzyme were investigated. Immobilization of enyzme to gelatin support increases the pH, temperature and operational stability due to the appropriate flexibility and structural rigidity. Activity of immobilized enyzme has decreased compared to free enyzme activity due to the steric hinderance effect and mass transfer limitations. The reusability of the enzyme entrapped gelatin film was also investigated; there was almost 60% decrease in activity of the film after fifth usage. During activity measurement, the color of the gelatin films becomes brown showing that quinone produced with enyzmatic reaction was bound on the film.