TiO2 nanoparticle dispersions in water and nonaqueous solvents studied by gravitational sedimentation analysis: Complementarity of Hansen Parameters and DLVO interpretations

Hansen Solubility Parameters (HSP) have been shown to be an effective approach for rationalizing and predicting the stability of titanium dioxide nanoparticles (TiO2 NPs) dispersions. However, interparticle electrostatic interactions, not considered in Hansen’s but taken into account DLVO theory, are expected play a significant role organic solvents having notable dielectric constant. Zeta potential ζ TiO2 P25 NPs was measured both aqueous media identify DLVO-stabilized dispersions from those stabilized by more specific NP-solvent interaction. Stability quantified using Turbiscan optical device which provides Stokes diameters Relative Index (RTSI). When zeta constant solvent high, dispersion benefits additional stabilization while when repulsion is negligible, only within sphere give stable The two interpretations therefore complementary describe behavior solvents.