Speaker
Description
Linear polymers in shear flow display a dominant mode of dynamics known as tumbling, around the vorticity axis, whereby the two ends exchange their places, accompanied by a temporary compression of the chain in the gradient direction. We will demonstrate that topological polymers respond to shear in dramatically different ways, emerging from a coupling between topology and hydrodynamics. In particular, we will discuss ring polymers as well as rings connected either chemically (bonded rings, BR) or mechanically (catenated rings, CR). Rings display vorticity swelling and an inflated phase that suppresses tumbling and Brownian motion. BRs tumble around an axis parallel to the gradient direction, whereas CRs show slip tumbling while maintaining their overall orientation and shape. These unusual phenomena all result from proper consideration of hydrodynamic interactions and they disappear if the latter are (artificially) switched off.
References
[1] M. Liebetreu and C. N. Likos, Communications Materials 1, 4 (2020).
[2] R. A. Farimani, Z. A. Dehaghanni, C. N. Likos, and M. R. Ejtehadi, Physical Review Letters 132, 148101 (2024).
