Dynamics of bottlebrush polymers in dilute solution

Highly branched polymers consisting of a central backbone chain hosting numerous densely grafted side chains, called bottlebrush polymers, have been widely studied for the design and manufacture of self-assembled
hierarchical soft materials. This architecture lends additional thickness to the molecule as
well as enhancing its stiffness, giving rise to very different static and dynamic
properties compared to linear polymers.
We present results from Brownian Dynamics simulations with
hydrodynamic interaction on bottlebrush dynamics in dilute solution, emphasizing
the role of side chain length on the intramolecular structure and rheological
properties. The dynamical simulations are performed on bead-spring polymer
models in simple shear and uniaxial extensional flows, with suitably chosen
interaction potentials. We discuss the degree of backbone and side chain
stretching as well as overall stress under both transient and steady-state
conditions. Furthermore, we characterize the different dynamical modes of
deformation of bottlebrush polymers in shear flow as a function of flow strength
and side chain length and contextualize this behavior with respect to the well
known dynamics of linear polymers.