Polymers pushing Polymers: Polymer Mixtures in Thermodynamic Equilibrium with a Pore

摘要

We investigate polymer partitioning from polymer mixtures into nanometer sizecavities by formulating an equation of state for a binary polymer mixtureassuming that only one (smaller) of the two polymer components can penetratethe cavity. Deriving the partitioning equilibrium equations and solving themnumerically allows us to introduce the concept of "polymers-pushing-polymers"for the action of non-penetrating polymers on the partitioning of thepenetrating polymers. Polymer partitioning into a pore even within a verysimple model of a binary polymer mixture is shown to depend in a complicatedway on the composition of the polymer mixture and/or the pore-penetrationpenalty. This can lead to enhanced as well as diminished partitioning, due totwo separate energy scales that we analyse in detail.