Scaling behavior of polymers at liquid/liquid interfaces

Abstract

The dynamics of a polymer chain confined in a soft 2D slit formed by two immiscible liquids is studied by means of molecular dynamics simulations. We show that the scaling behavior of a polymer confined between two liquids does not follow that predicted for polymers adsorbed on solid or soft surfaces such as lipid bilayers. Indeed, our results show that in the diffusive regime the polymer behaves like in bulk solution, following the Zimm model, and with the hydrodynamic interactions dominating its dynamics. Although the presence of the interface does not affect the long-time diffusion properties, it has an influence on the dynamics at short time scale, where for low molecular weight polymers the subdiffusive regime almost disappears. Simulations carried out when the liquid interface is sandwiched between two solid walls show that, when the confinement is a few times larger than the blob size, the Rouse dynamics is recovered.