Dispersion and Flocculation Behavior of Metal Oxide Powders in Organic Solvent.

Enhanced dispersion stability and photocatalytic activity of TiO2 particles fluorinated by fluorine gas

“…suspension (a), TiO 2 particles reformed into large agglomerates within 4 h in all solvents. Especially in ethanol (24.3) and acetone (20.7), which have a lower dielectric constant than water (78.3) [10], decreased turbidity in the untreated TiO 2 suspension (a) was observed within 1 h. The dielectric constant of a substance is closely related to the dipole moment. Also, the polarity of a substance with a high dielectric constant is considered to be large.…”

“…It is important to consider the high cost of surfactants required and the residues generated in the particles. Al 2 O 3 and TiO 2 metal oxide particles tend to disperse in a highly polar solvent; in contrast, they tend to flocculate in a low dielectric solvent because the Hamaker constant between the particles is high in such a solvent [10,11]. TiO 2 particles generally disperse well in water but not in other solutions such as acetone and ethanol.…”

Hansen Solubility Parameters for Octahedral Oligomeric Silsesquioxanes

“…In general, the Hansen Solubility Parameter approach has been limited to purely organic compounds, with only a few investigations performed for inorganic groups , (mainly in the context of nanoparticles or surfaces − ,− ), or for organic/inorganic polymers, such as polysiloxanes − and polyphosphazines . The size and even shape of POSS molecules, however, would not be expected to preclude the determination of HSP because the HSP approach has been successfully applied to compounds such as fullerenes, , asphaltenes, − and bitumen , that are intermediates between small molecules and polymer chains.…”

Dispersion and Flocculation Behavior of Fine Metal Oxide Particles in Various Solvents [Translated]^†

“…In this study, the relationship between dispersibility of fine particles and various properties of the solvent, such as dielectric constant and solubility parameters, was investigated in various solvents [7,8]. The median diameters of fine particles of Al 2 O 3 , TiO 2 and Fe 2 O 3 were measured in various solvents to evaluate the dispersibility of particles, and also Hansen's solubility parameters were used for the evaluation of dispersibility of fine particles in various solvents.…”