Rheological properties of TiO2 suspensions varied by shifting the electrostatic inter-particle interactions with an organic co-solvent

Abstract The rheology of mineral suspensions is a key factor in many application fields. In particular, adjusting either the solid amount or the solvent composition appears as a possibility to control the rheological properties. These modifications should lead to variations of the electrostatic inter-particle interactions influencing thus the suspensions viscoelastic behavior. TiO 2 suspensions were firstly formulated in water by adjusting the pH close to the isoelectric point of the TiO 2 nanoparticles. The influence of the solid amount as well as the pH was study and coupled to the rheological properties of aqueous suspensions. In a second time, a part of water was substituted by an organic solvent (i.e. ethanol). Rheological measurements were performed and coupled to the zeta potentials of the TiO 2 into different solvents. The rheological properties of TiO 2 suspensions were adjusted by varying the electrostatic inter-particle interactions. The pH has to be close enough to the TiO 2 isoelectric point and the particle concentration high enough to create a percolating network. With adding ethanol, transient shear thickening is suppressed and, even far from the isoelectric point, the resulting flocculated suspensions show high yield stresses over a large pH range.