Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

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Access type: Open accessSubject: search.filters.subject.Supercritical ethanol drying

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  • Article
    Citation - Scopus: 1
    Optical and Surface Properties of Zinc Oxide Nanoparticles Dried by Conventional and Supercritical Ethanol Drying Techniques
    (Research India Publications, 2014) Egbuchunam, Theresa Obuajulu; Yetgin, Senem; Balköse, Devrim; Balköse, Devrim; Özmıhçı, Filiz; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Zinc oxide (ZnO) nanoparticles were synthesized by conventional (ZnO-A) and supercritical ethanol drying (ZnO-B). Nitrogen adsorption/desorption analyses were performed to determine the surface areas of the powders. The specific surface area was 28.30m2/g and 10.61 m2/g for ZnO-A and ZnO-B respectively. The powders adsorbed very small amount of CO2with the conventionally dried powder adsorbing more CO2. Supercritical ethanol dried ZnO had ethanol on its surface which was eliminated by vacuum application at room temperature. Both powders had OH groups which were eliminated on heating up to 500°C under vacuum. However, OH groups were present in lower amounts in supercritical ethanol dried ZnO. The powders were characterized by UV-VIS optical absorption and room temperature photoluminescence spectroscopic analyses. The UV-VIS absorption spectrum showed an absorption band at 375nm due to ZnO nanoparticles. The photoluminescence spectrum of ZnO excited at 380nm exhibited three emission peaks: one at 424nm and 490nm corresponding to band gap excitonic emission and another located at 520nm due to the presence of singly ionized oxygen vacancies.
  • Article
    Citation - WoS: 10
    Citation - Scopus: 13
    Effect of Supercritical Ethanol Drying on the Properties of Zinc Oxide Nanoparticles
    (Taylor and Francis Ltd., 2012) Egbuchunam, Theresa; Balköse, Devrim; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    The synthesis, characterization, and application as polymers and anti-wear additives of nanosized zinc oxide particles obtained by conventional and supercritical ethanol drying are reported in this study. The nanaoparticles of ZnO produced by the two different drying techniques were characterized using Fourier Transform Infrared (FT-IR) spectrophotometry, Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and Thermogravimetric analysis (TGA) to elucidate the shape, size, composition, and stability of the nanoparticles. ZnO nanoparticles were then applied to poly (vinyl chloride) (PVC) powder and light mineral oil to assess their effectiveness and suitability as additives in diverse areas. XRD analysis revealed ZnO crystalline structure with average particle size of 24.7 nm for zinc oxide nanoparticles prepared by supercritical ethanol drying while SEM showed well-isolated and monodisperse particles with average size of 61.08 nm. © 2012 Copyright Taylor and Francis Group, LLC.