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Preparation of Highly Dispersed Ultrafine Barium Titanate Powder by Using Microbial‐Derived Surfactant
Author(s) -
Kamiya Hidehiro,
Gomi Kenjiro,
Iida Yuichi,
Tanaka Kenji,
Yoshiyasu Takashi,
Kakiuchi Toshihito
Publication year - 2003
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.2003.tb03601.x
Subject(s) - pulmonary surfactant , materials science , chemical engineering , suspension (topology) , stoichiometry , barium titanate , dispersion (optics) , phase (matter) , nanometre , amorphous solid , particle size , chemistry , composite material , organic chemistry , ceramic , physics , mathematics , optics , homotopy , pure mathematics , engineering
To uniformly disperse ultrafine BaTiO 3 particles with a stoichiometric composition and several tens of nanometers in diameter to primary particles during the sol–gel synthesis process, a new aqueous surfactant with a high hydrophilic group density and special cis‐structure was prepared from a microbial product and added to solution before the sol–gel synthesis reaction. Because of the rapid formation of large and porous aggregates which were 30–50 μm in diameter in suspension without addition of this unique structural surfactant, the prepared ultrafine BaTiO 3 particles caused rapid sedimentation in suspension. The addition of the surfactant in the range of 7.1 wt% for the synthesized BaTiO 3 particles made it possible to decrease the size of the aggregates in suspension as well as the sedimentation velocity while maintaining the stoichiometric composition. The optimum additive content to obtain the minimum aggregate size of about 100–200 nm in diameter and the highest dispersion stability in suspension while maintaining the stoichiometric composition of prepared ultrafine BaTiO 3 particles without other phases was determined at about 7.1 wt%. Because the excess addition of this surfactant at more than 8.5 wt% inhibited the uniform synthesis of BaTiO 3 particles, an amorphous phase with a highly specific surface area and a BaCO 3 phase formed in the synthesized particles.