Structure and dynamics of confined polymer chain in dilute solution

The structure and dynamics of confined single polymer chain in dilute solution, either in equilibrium or subjected to different flow fields, are investigated by means of dissipative particle dynamics simulations. The no-slip boundary condition without density fluctuation near the wall is taken into account to mimic the environment of a nanochannel. The dependence of the radius of gyration and the diffusion of the chain on the strength of the confinement and the solvent quality is studied. In non-equilibrium systems, both the Couette flow and the Poiseuille flow acting on a dilute polymer solution are investigated. The effect of the interaction between polymer and solvent under these two flow conditions are found to be the same: the polymer migrates to the center of the channel when the interaction was reduced. With increasing the flow strength, there are two peaks with a dip in the center of the polymer density profile in the Poiseuille flow and only one peak in the center in the Couette flow, which are in agreement with the previous investigations.