Premium
Generation of unagglomerated, Dense, BaTiO 3 particles by flame‐spray pyrolysis
Author(s) -
Brewster James H.,
Kodas Toivo T.
Publication year - 1997
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690431310
Subject(s) - materials science , pyrolysis , chemical engineering , particle (ecology) , melting point , tetragonal crystal system , diffusion flame , phase (matter) , premixed flame , diffusion , adiabatic flame temperature , barium , barium titanate , aerosol , analytical chemistry (journal) , combustion , composite material , ceramic , chemistry , thermodynamics , chromatography , metallurgy , organic chemistry , engineering , combustor , oceanography , physics , geology
Fine particles of dense, high‐purity, crystalline BaTiO 3 were produced by flame‐spray pyrolysis. A 0.5‐M (Ba:Ti = 1:1) solution of barium acetate, titanium lactate, and water was aerosolized using an ultrasonic generator, and the droplets were delivered into the core of an annular diffusion flame (H 2 /air) reactor. For all investigated temperatures [∼1,000–∼2,000°C adiabatic], the generated powders were chemically pure, crystalline (primarily tetragonal phase with hexagonal and cubic polymorphs), and unagglomerated. At a low‐flame temperature (∼1,000°C ad.), the particles produced were hollow and irregularly shaped. Particles produced at higher flame temperatures (>∼1,500°C ad.) were dense and homogeneous. Particles showed a transition from a nonspherical porous morphology to a spherical dense morphology with increasing temperature. By increasing residence time, the temperature at which particles became spherical and dense was reduced. Flame‐spray pyrolysis provides a useful method for forming dense particles of high melting point materials by aerosol‐phase densification.