Effects of contraction ratio on non-linear dynamics of semi-dilute, highly polydisperse PAAm solutions in microfluidics

► Data span from molecular to flow characterization for PAAm solutions are obtained. ► Nonlinear flow regimes are identified and correlated to vortex growth mechanisms. ► Viscoelastic flows are dependent on Wi and Re number, the details of flow geometry. ► Viscoelastic flows are also sensitive to the molecular weight distribution of polymer.