Influence of solvation interactions on the zeta potential of titania powders

The influence of solvation interactions on the surface charge of titania powders was studied by means of linear solvation energy relationships (LSER). The zeta potential (ZP) of titania powders and the effect of water content were determined in a series of alcohols, including methanol, ethanol, 1-propanol, isopropanol, and 1-butanol. The ZPs against the solvents' 13 LSER descriptors were analyzed by principal component analysis (PCA), cluster analysis, multiple linear regression (MLR), and stepwise multiple regression (SMR). Very good correlation between ZP and LSER parameter was obtained. One LSER parameter, relative dielectric constant, ε, was used to establish the LSER equation. The ZP of titania powders in pure alcohols can be reasonably calculated by an empirical formula: ZP=13.43−213.63·1/ε. The results show that ε is the most important factor governing the ZP of titania powders. The results also suggest that the effect of solvation interactions on ZP is a result of the electrostatic interactions between powders and solvents.