T. Kawai et al., SYNTHESIS OF MONODISPERSE ZRO2 PARTICLES IN POLYOXYETHYLATED NONIONICREVERSED MICELLES, Colloids and surfaces. A, Physicochemical and engineering aspects, 109, 1996, pp. 245-253
The solubilization region of sulfuric acid in a cyclohexane solution o
f polyoxyethylene(6)nonylphenyl ether can be divided into three realms
, i.e. reversed micelle, swollen micelle and water/oil (W/O) microemul
sion, depending on the solubilized state of water. Monodisperse spheri
cal particles are found to be produced by hydrolyzing zirconium tetra-
n-butoxide in the reversed and swollen micelle, but in the W/O microem
ulsion their size is broadly distributed. FT-IR and X-ray diffraction
measurements have revealed that particles in all realms contain sulfat
e ions, but the ions are easily removed by washing in ammonia solution
and the washed particles are amorphous hydrated ZrO2. Further, it has
been determined that crystalline ZrO2 particles can be obtained by ca
lcinating the washed particles at 800 degrees C.