Shear Thickening Properties Research Articles

Associating polymers and shear thickening

The shear-thickening property observed in ionomer solutions is discussed. Scattering and dynamic modulus data suggest that the ionic groups cluster into multiplets and that these control the relaxation of stress. A simple mechanism for shear thickening is described ; it leads to the expectation that these clusters must be bound with a certain minimal strength. Associations with the strength required are argued to pose serious problems for solubility. These problems worsen with increasing number of ions in a multiplet. The competing interactions which determine this number are described.

The elastico-viscous properties of deflocculated china clay suspensions

The physical properties of deflocculated china clay suspensions are studied in a combined steady and low-amplitude oscillatory shear flow. Qualitative agreement is obtained between theory and experiment, and it is shown (for the first time) that it is possible to characterize shear thinning and shear thickening properties of a fluid using one equation of state. At the high concentrations considered it is found that particular china clay suspensions exhibit marked elastic properties. The experimental results, obtained from a Weissenberg rheogoniometer, indicate that this work may have important implications for certain industrial nearly viscometric flow situations.