The objective of this study is to investigate the relation between the flocculation and dispersion of Al₂O₃, TiO₂ and Fe₂O₃ particles and the properties of solvents such as dielectric constant and solubility parameters. The median diameter of these metal oxide particles was measured in many organic solvents. The effect of the kind of solvent on the flocculation/dispersion behavior of metal oxide particles was evaluated from these results.
Hansen’s solubility parameters with three dimensions were applied to the evaluation of the flocculation/dispersion behavior for fine metal oxide particles in organic solvents. The numeral balance among the Hansen’s solubility parameters of various solvents was plotted in a triangular chart, and then the points of solvents with similar median diameter of the particle were linked. In the triangular chart, these linked lines were not intersected each other and there was the specific point at which the best dispersibility of the particles was obtained.

^† This report was originally printed in Kagaku Kougaku Ronbunshu, 27(4), 497-501 (2001) in Japanese, before being translated into English by KONA Editorial Committee with the permission of the editorial committee of the Soc. Chemical Engineers, Japan.