(521d) Mesoscale Modeling of Polymer Solutions Under Flow

Polymer solutions exhibit a rich variety of structural and rheological behaviors under flow. It is of particular interest to link the microscopic properties of the polymers, such as the chain length or topology, to the macroscopic properties of the solution, such as the zero-shear viscosity. Computer simulations have emerged as useful tools for such studies because they allow for simultaneous measurement of the polymer structure and dynamics and rapid exploration of parameter space. Because of the inherent disparity of length and time scales present in polymer solutions, mesoscale models incorporating microscopic detail of the polymers and faithfully resolved hydrodynamic interactions have become favored tools for such studies. We have recently developed a massively-parallel, open-source implementation of the multiparticle collision dynamics (MPCD) method that significantly accelerates mesoscale simulations of polymer solutions using graphics processing units. Shear flow is generated by a reverse nonequilibrium molecular dynamics method, which is shown to have some previously unappreciated limitations for macromolecules that must be carefully handled. We apply the MPCD method to solutions of flexible and semiflexible polymers as well as telechelic star polymers, connecting the microscopic polymer conformations in flow to the emerging rheological properties.