WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article Citation - WoS: 5Citation - Scopus: 6Manufacturing Radar-Absorbing Composite Materials by Using Magnetic Co-Doped Zinc Oxide Particles Synthesized by Sol-Gel(SAGE Publications Inc., 2020) Atay, Hüsnügül Yılmaz; İçin, ÖyküAn indicator of being a strong country in today's world is that they have powerful weapons. In this sector where science is used exceedingly, the "stealth" takes an important place. Radar-absorbing materials are used in stealth technology to disguise an object from radar detection, such that it can allow a plane to be perceived as a bird. In this study, Co-doped zinc oxide reinforced styrofoam sheet composites were manufactured as radar-absorbing materials. For this purpose, Co-doped zinc-ZnO particles were synthesized via the Sol-Gel method with doping concentrations of 0%, 3%, 6%, 9%, and 12%. They were embedded in a styrofoam matrix with different loading levels to see the concentration dependence. The as-prepared powders were characterized by using X-ray diffraction and Scanning Electron Microscope-Energy Dispersive Spectroscopy. Magnetic characterization of samples was carried out using a vibrating sample magnetometer. Finally, the radar-absorbing test was applied with a network analyzer to achieve the main purpose of this research. It was concluded that Co-doped zinc oxide reinforced composites have electromagnetic properties that indicate potential applications in the radar-absorbing area.Conference Object Citation - WoS: 22Citation - Scopus: 22Propylene Epoxidation: High-Throughput Screening of Supported Metal Catalysts Combinatorially Prepared by Rapid Sol-Gel Method(Springer Verlag, 2010) Önal, Işık; Düzenli, Derya; Seubsai, Anusorn; Kahn, Michael; Şeker, Erol; Senkan, Selim M.The gas phase oxidation of propylene using molecular oxygen was studied on a variety of supported metal catalysts. The most promising PO activity was obtained for Cu supported on high surface area SiO 2 and the multimetallic systems exhibit synergistic effects that increased the desired PO yield by several folds for Ag promoted with Cu on SiO 2 after screening a large number of catalysts by a high throughput testing technique. © 2009 Springer Science+Business Media, LLC.Article Citation - WoS: 46Citation - Scopus: 53Preparation and Characterization of Fe2o3-Tio2 Thin Films on Glass Substrate for Photocatalytic Applications(Elsevier Ltd., 2006) Çelik, Erdal; Yıldız, A. Y.; Ak Azem, Necmiye Funda; Tanoğlu, Metin; Toparlı, Mustafa; Emrullahoğlu, Ö. Faruk; Özdemir, İ.Fe2O3-TiO2 coatings were successfully prepared on glass slide substrates using sol-gel method for photocatalytic applications. The phase structure, thermal, microstructure and surface properties of the coatings were extensively characterized by using X-ray diffractometry (XRD), differential thermal analysis/thermograviometry (DTA/TG), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Their adhesion and absorbance properties were investigated by a scratch tester and UV-vis spectroscopy. Four different solutions were prepared by changing Fe/Ti molar ratios. Glass substrates were coated by solutions of Ti-alkoxide, Fe-chloride, glaciel acetic acid and isopropanol. The obtained gel films were dried at 300 °C for 10 min and subsequently heat-treated at 500 °C for 5 min in air. The oxide thin films were annealed at 600 °C for 60 min in air. The influence of Fe3+ concentration and number of layers on structure of the films was established. In addition, XRD results revealed that Fe2O3-TiO2 films composed of TiO2, Fe2Ti3O9, Ti3O5 and Fe3O4 phases. According to DTA/TG result, it was determined that endothermic and exothermic reactions were formed at temperatures between 80 and 650 °C due to solvent removal, combustion of carbon based materials and oxidation of Fe and Ti. SEM observations exhibited that the coating structure becomes more homogeneous depending on an increase of Fe/Ti molar ratios and thus a regular surface morphology forms with increasing Fe/Ti ratio. It was also seen that as the Fe/Ti ratio increases the surface roughness of the films increases. Critical adhesion force of thin films with Fe/Ti ratio of 0, 0.07, 0.18 and 0.73 were found to be 9, 25, 28 and 21 mN, respectively. The methylene blue solutions photocatalyzed by TiO2 based thin films shows characteristic absorption bands at 420 nm.