Chemical Engineering / Kimya Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/14

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Author: search.filters.author.Çelik, ErdalSubject: search.filters.subject.Ceramics

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  • Article
    Citation - WoS: 15
    Citation - Scopus: 12
    Solubility and Aging of Lead Magnesium Niobate in Water
    (Elsevier Ltd., 2009) Şakar-Deliormanlı, Aylin; Çelik, Erdal; Polat, Mehmet
    Lead magnesium niobate (PMN) is an important relaxor ferroelectric material commonly employed in multilayer capacitor and actuator manufacturing owing to its high dielectric constant and superior electrostrictive properties. However, stability of this material in water is not very well known and there is need for a detailed investigation. In this research, solubility of lead magnesium niobate powders in water was determined as a function of solids concentration. The obtained results showed that the amount of cation leaching from the PMN surface depends on the pH value of the suspension and the solids concentration. The Pb2+ and Mg2+ ion dissolution was very high especially in the acidic pH range. Nevertheless, neither the dissolution mechanism nor the effects of dissolved ions on the stability were the same for those ions. The study provides new aspects on the solubility of perovskite materials which possess more than one soluble cation in their structure.
  • Article
    Citation - WoS: 3
    Citation - Scopus: 3
    Influence of Dispersing Agents on the Solubility of Perovskites in Water
    (Taylor and Francis Ltd., 2009) Şakar-Deliormanlı, Aylin; Çelik, Erdal; Polat, Mehmet
    In this study, solubility behavior of lead magnesium niobate (PMN) powders in water was investigated in the presence of pure polyacrylic acid and polyacrylic acid/polyethylene oxide comb polymers. Experiments were performed by measuring the solubility of PMN in terms of the concentration of Pb+2 and Mg+2 ions in supernatant as a function of pH and dispersing agent dosage. The concentrations of the metal ions in supernatant were found to be affected by the dispersant concentration, stirring time and the suspension pH. Results revealed that both dispersing agents enhance the cation dissolution from PMN surface at pH 9 due to weak (reversible) adsorption and complexation of Pb+2 and Mg+2 by carboxylate groups. On the other hand, under acidic conditions cation dissolution from PMN is inhibited and this was attributed to the strong adsorption of dispersing agents onto the powder surface and formation of a dense polymer layer.