Effect of particle concentration on physical properties of titanium dioxide suspensions

The effect of particle concentration on physical properties of aqueous and non-aqueous (methanol) TiO2 suspensions was studied with and without polyvinylpyrrolidone (PVP). The relative viscosity measured as a function of particle volume fraction (Phi) agrees well with the prediction of the Eiler's equation and the Maron-Pierce's equation. The maximum packing fraction (Phi(m)) determined from the equations agree well with the maximum packing fraction determined from sedimentation experiment. The maximum packing fraction of sterically stabilized methanol based suspension by PVP adsorption is about equal to the closest packing fraction of spheres. Dynamic muduli (G', G '') of flocculated suspensions increases much more rapidly with Phi than that of the sterically stabilized suspensions and the storage modulus, G', increases more rapidly than the loss modulus, G '', indicating that the suspension becomes more elastic as Phi increases.