抄録
The effect of post-synthesis process, such as washing and drying of nanoparticles, on their redispersion behavior in solvents were investigated by using TiO2 nanoparticles (c.a.5 nm) modified with oleyl phosphate (TiO2-OP). The washing process conducted in this article was dispersion of TiO2-OP in toluene and collection by centrifugation after flocculating the particles by adding poor solvent. When TiO2-OP cake was simply vacuum dried after washing, the average size after their redispersion with ultra-sonication in toluene was c.a. 40 nm. It was found that this average size gradually reduces to 20 nm by settling the suspension. Contrary, when TiO2-OP was dried by evaporating the solvent after dispersing the cake in toluene, their average size in toluene easily reduced to 20 nm just after treating ultra-sonication. The behavior of these differently dried TiO2-OP during redispersion process in toluene is discussed based on the structure of ligands and particle interactions in toluene.
