Observations of wall slip and shear banding in an entangled DNA solution
We have studied nonlinear flow behavior of entangled DNA solutions using particle tracking velocimetry in Couette and cone/plate geometries. At apparent shear rate γ̇app < 0.1 s−1, the velocity profile is linear across the gap. Beyond the terminal region with γ̇app < 40 s−1, the velocity profile becomes temporarily banded after the stress maximum and shows massive wall slip at long times with little shear banding in the bulk. At γ̇app > 40 s−1, the velocity profile progressively curves and becomes banded with a sharp interface after hundreds of strain units. In the steady state, the thickness of high-shear band increases linearly with the apparent shear rate. At γ̇app = 1000 s−1, the velocity profile returns to linearity.
Wang, Shi-Qing, "Observations of wall slip and shear banding in an entangled DNA solution" (2008). Polymer Science Faculty Research. 604.