Organic Suspension Behavior of Rutile TiO₂ Nanoparticles with High Specific Surface Area

Abstract

Sedimentation properties of the TiO₂ nanoparticles with very high specific surface area (about 180 m²/g) based on the BET method have been investigated in various organic solvents. The TiO₂ nanocolloid in the isopropyl alcohol displayed a considerably high electrostatic repulsive force, compared to that in other solvents, with negligible coalescence between the particles. Both the backscattered light flux measurements and scanning electron microscopy confirmed that in the cases of water, methyl alcohol and ethyl alcohol, a progressive sedimentation of the TiO₂ particles was observed at the bottom due to a flocculation-induced particle growth, while a very stable TiO₂ dispersion was observed in isopropyl alcohol.