Rheological behaviors of nanosilica suspensions with different dispersion levels prepared by the bead milling technique

The different dispersion levels of silica nanoparticles in organic suspensions were deliberately fabricated using the bead milling technique by controlling the milling time. The dispersion level was confirmed by the dynamic light scattering technique, the transmission electron microscopy, the stability of the suspensions as well as the optical properties of the coatings made from the suspensions. The rheological behaviors of the suspensions were investigated by the steady and dynamic shear tests. It was found that larger agglomerations had a stronger impedence for suspension to flow, leading to a higher viscosity and stiffness. Some important rheological parameters were correlated with the dispersion levels of the suspensions and the reasonable explanation was discussed.