Barium ion leaching from barium titanate powder in water

A submicrometer-sized commercial BaTiO3 (BT) powder was aged in water under three different conditions: pH, aging times, and pre-heat treatments of the powder. The amount of Ba2+ ions leaching from the BT particles was determined by the EDTA titration method. As predicted by thermodynamic calculation, the greater extent and the faster rate of Ba2+ leaching were found at the lower solution pH, leveling off at pH 8. The pre-heat treatments of the BT powder increased the amount of Ba2+ leaching when compared to the as-received one. This result was shown by the formation of soluble surface BaCO3, which was detected using FT-IR spectroscopy. It was also shown that organic passivation agents were effective reducing the Ba2+ leaching but at high solution pH. (C) 2003 Kluwer Academic Publishers.