(371a) Effects of Fluctuating Hydrodynamic Interactions On the Dynamics of Confined Polymer Solutions: Grooved Channels and Pore-Translocation Rates

We present results of simulations of solutions of flexible polymers molecules during flow. A self-consistent coarse-grained Langevin description of the polymer dynamics is adopted in which hydrodynamic effects are included through a Green's function formalism. The O(N) General Geometry Ewald-like Method is used to calculate the confined Stokeslet and concentrations in the range from ultra-dilute to semi-dilute (near the overlap concentration). For flowing polymer solutions in a grooved channel, the groove is almost completely depleted of polymer chains at high Weissenberg number in the dilute limit, but at finite concentration this depletion effect is dramatically reduced. Only upon inclusion of hydrodynamic interactions can these phenomena be properly captured. The rate constant for flow-induced translocation of polymer molecules through a square channel has been calculated using the Forward Flux Sampling method. The rate constant is affected by the walls and the confinement provided that hydrodynamic interactions are taken into account. Such interactions lead to a decrease of the rate constant due to the decrease in particle mobility near rigid walls, and an increase due to the increase of the diffusion coefficient of hydrodynamically interacting polymer molecules.