Zeta potential in dispersions of titania nanoparticles in moderately polar solvents stabilized with anionic surfactants

Electrophoretic mobility of titania nanoparticles in ethane-1,2-diol and in propane-1,2-diol in the presence of SDS and sodium octadecylsulfate was measured. Several dispersions were acidified with HCl or alkalized with NaOH. Addition of acid resulted in positive and addition of base resulted in negative zeta potential. Anionic surfactants have moderate effect on the zeta potential. They enhanced negative zeta potential, but their effect became significant at surfactant concentrations as high as 1 g/L. Sodium octadecylsulfate was more efficient than SDS in shifting the zeta potential to more negative values.