Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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Author: search.filters.author.Çakıcıoğlu Özkan, FehimePublisher: search.filters.publisher.Elsevier Ltd.

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  • Article
    Citation - WoS: 13
    Citation - Scopus: 17
    Effect of Ultrasound on the Kinetics of Cation Exchange in Nax Zeolite
    (Elsevier Ltd., 2012) Erten Kaya, Yasemin; Çakıcıoğlu Özkan, Fehime; 01. Izmir Institute of Technology
    In this study, we focused on the effect of ultrasound on ion exchange kinetics to obtain the Li-, Ca- and Ce-rich NaX zeolite. The results were compared to those obtained from the traditional batch exchange method under similar conditions. Contact time and initial cation concentration (fold equivalent excess) were studied. Ultrasound enhanced the replacement of Na + ion with Li +, Ca 2+ and Ce 3+ ions in the extra-framework of zeolite up to 76%, 72% and 66%, respectively. The intraparticle diffusion is the rate limiting step in the ion exchange for both exchange methods. As compared to the traditional exchange method, the ultrasonic method applied in this study was found to be very effective on the exchange amount at equilibrium.
  • Article
    Citation - WoS: 112
    Citation - Scopus: 130
    The Effect of Hcl Treatment on Water Vapor Adsorption Characteristics of Clinoptilolite Rich Natural Zeolite
    (Elsevier Ltd., 2005) Çakıcıoğlu Özkan, Fehime; Ülkü, Semra; Ülkü, Semra; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    In this study, water vapor adsorption properties of the clinoptilolite rich zeolite tuff, from Bigadic (Turkey), and its modified forms were examined. The modified forms were obtained by treating the tuff with HCl solutions (0.032, 0.16, 0.32, 1.6 or 5 M) at 25,40,75 and 100°C for 3 h. Infrared spectroscppy and water vapor adsorption were used for the characterization of the zeolites. Langmuir, BET and Dubinin-Raduschevich methods were applied in the analysis of water vapor adsorption data. Applications of Dubinin Raduschevich equation to the water adsorption data displayed that the super-micropore volume was not very sensitive to acid treatment. It was found out that the Langmuir surface area and ultra-micropore volume depend on the degree of the removal of aluminum from the structure.