Shear thinning

[3] Shear thinning is the most common type of non-Newtonian behavior of fluids and is seen in many industrial and everyday applications.

[4] Although shear thinning is generally not observed in pure liquids with low molecular mass or ideal solutions of small molecules like sucrose or sodium chloride, it is often observed in polymer solutions and molten polymers, as well as complex fluids and suspensions like ketchup, whipped cream, blood,[5] paint, and nail polish.

The value of η∞ represents the lowest viscosity attainable and may be orders of magnitude lower than η0, depending on the degree of shear thinning.

This behaviour is usually seen in polymer/silica micro- and nanocomposites, where the formation of a silica network in the material provides a solid-like response at low shear stress.

The shear-thinning behavior of plastic fluids can be described with the Herschel-Bulkley model, which adds a threshold shear stress component to the Ostwald equation:[8] Some authors consider shear thinning to be a special case of thixotropic behaviour, because the recovery of the microstructure of the liquid to its initial state will always require a non-zero time.

[11] When modern wall paint is applied, the shear created by the brush or roller will allow it to thin and wet out the surface evenly.

Ketchup is a shear-thinning material, viscous when at rest, but flowing at speed when agitated by squeezing, shaking, or striking the bottle.