Room‐Temperature Solubility Behavior of Barium Titanate in Aqueous Media

2009

Ceramics International

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 Pb 2+ and Mg 2+ 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. #

“…Previously Neubrand et al [12] investigated the dissolution of Ba 2+ ions from the barium titanate in water. They found that the amount of barium leached increases as the pH decreases.…”

Section: Resultsmentioning

confidence: 99%

Solubility and aging of lead magnesium niobate in water

Şakar‐Deliormanlı

2009

Ceramics International

“…Previously, Neubrand et al 8 investigated the dissolution of Ba 21 ions from the barium titanate in water. They found that the amount of barium leached increased as the pH decreases.…”

Section: Resultsmentioning

confidence: 99%

“…The few studies on this subject include the preparation of PMN-lead titanate (PMN-PT) suspensions in solvents other than water [4][5][6] whereas detailed work is present on barium titanate system in water. 7,8 Therefore, understanding of the PMN-H 2 O system is essential in producing high-quality PMN ceramics.…”

mentioning

confidence: 99%

The Isoelectric Point of Lead Magnesium Niobate

Deliormanlı

Journal of the American Ceramic Society

2007

Lead magnesium niobate (PMN) is an important relaxor ferroelectric material commonly used in multilayer capacitor and actuator manufacturing owing to its high dielectric constant and superior electrostrictive properties. However, the isoelectric point of this material in water is not known and there is justification for a detailed investigation. In this work, the isoelectric point (IEP) of aqueous PMN suspensions were determined as a function of solids concentration. Results showed that IEP of the PMN suspensions strongly depended on the solids loading. The IEP was between pH 9 and 10 at particle concentrations between 10 to 20 vol%. The IEP shifted gradually to a lower pH value as the particle concentration decreased. Solubility experiments showed that Pb 21 and Mg 21 ions dissolved from the PMN surface, especially in the acidic pH range. The study provides a new insight on the aqueous stability of perovskite materials which possess more than one soluble cation in their structure.

“…The surface layer around the PMN increases surface acidity of the powder. Therefore, the IEP of the powder decreases as the surface layer increases [14][15][16]. Fig.…”

Section: Turbidity Measurementsmentioning

confidence: 95%

Adsorption of anionic polyelectrolyte and comb polymers onto lead magnesium niobate

Şakar‐Deliormanlı

Colloids and Surfaces A: Physicochemical and Engineering Aspect

2008

This paper presents the results concerning the adsorption mechanism of polyacrylic acid (PAA) and polyacrylic acid/polyethylene oxide (PAA/PEO) comb polymer onto lead magnesium niobate (PMN) powders. In the study adsorption behavior of PAA and PAA/PEO onto PMN surface were determined in aqueous solutions and the influence of pH and ionic strength was investigated. Results showed that adsorption of PAA or PAA/PEO increased with decreasing pH of the suspensions. The increase in the ionic strength or the presence of divalent cations caused an increase in the adsorption of both polyelectrolytes. It was observed that the adsorption reaches a maximum when PAA is fully complexed in solution. On the other hand, the increase in the adsorption of PAA/PEO onto PMN in the presence of monovalent or divalent salt was attributed to the decrease in the electrostatic forces rather than complex formation with the divalent metal ions in solution. Turbidity measurements showed that there is no complex formation between the divalent metal ions and PAA/PEO comb polymers due to shielding effect of the PEO teeth.