Efficient Dispersants for TiO ₂ Nanopowder in Organic Suspensions

Abstract

This article discusses the appropriate dispersant for titania (TiO 2 ) nanopowder in organic‐based suspensions. Four types of oleyl‐based dispersants, namely, oleyl alcohol, oleic acid, oleylamine, and oleyl phosphate, which have the functional groups hydroxyl (– OH ), carboxyl (– COOH ), amino (– NH 2 ), and phosphorous [–P(=O)( OH ) 2 ], respectively, were compared for their ability to disperse TiO 2 . Experimental results for zeta potential, adsorption, FT ‐ IR spectroscopy, and rheology, as well as theoretical calculations, indicate that dispersants with –P(=O)( OH ) 2 and – NH 2 were more efficient than those with – COOH or – OH . The primary reason for this difference is related to the different interactions of TiO 2 with various dispersants and to different dispersion mechanisms. In addition to the major functional groups, – OH in the chemical structure of dispersants was important, as it might have other effects such as destabilization of the suspensions.