The Effective Flory-Huggins Parameter in Polarizable Polymeric Systems: One-loop Theory and Field-theoretic Simulations

We apply a recently-introduced polarizable field theory to polymeric systems containing polarizable (and, optionally, charged) species. This framework, in which classical Drude oscillators are attached to the polymer segments, self-consistently incorporates dielectric response, van der Waals interactions and ion self-energies. The van der Waals interactions in a system with polarizability contrast give rise to an enhanced effective Flory-Huggins parameter, which we show can be estimated via a renormalized one-loop approximation. By complex Langevin sampling of the fully-fluctuating polarizable field theory, we simulate a diblock copolymer melt with species polarizability contrast and measure the enhancement of the Flory-Huggins parameter, finding excellent agreement with the renormalized one-loop theory. The effective Flory-Huggins parameter is sensitive to electrostatic screening, in a manner that is clarified by the one-loop theory. We discuss implications of this work for the phase behavior of polarizable and/or charged polymeric systems.