Rheology of Fine Particle Suspension from Low to High Concentration: Static Properties

The rheological properties of fine particle suspension can be measured by the ordinary rheometer for a relatively low density suspension (LDS) and the uni-axial compression loading test for a highly filled suspension (HFS). Since a suspension with a low concentration has a yield stress, LDS has a static elasticity as well as HFS. The purposes of this work are; 1) to study whether the elasticity is conserved over the whole concentration range from LDS to HFS, and 2) to examine whether the physical implication of yield stress of LDS is similar to that of the rupture stress of HFS from the viewpoint of destruction force between particles. Through the elasticity measurements for four different types of suspensions of fine particles, we obtained unique curves at different concentrations from LDS to HFS for each suspension, and therefore found that the elasticity is one of the representative properties of suspension. Another important finding is that a strong linear relationship exists between the rupture stress and the elasticity of HFS being independent of the type of suspension. Therefore, some uncertainty remains as for the purpose 2) even though the yield stress and the rupture stress gave a continuous curve over wide range of concentration.