Equilibrium partition coefficient of macromolecules between random porous network and bulk liquid

Abstract

An analysis is made of the equilibrium partitioning of macromolecules between a random porous network and a bulk liquid. For porous material, a randomly embedded model is employed, in which the solid phase is defined as the region occupied by the solid phase elements randomly placed in space. Three typical solid phase elements are considered, i.e., sphere, rod and flexible chain. A simple formula is obtained for the equilibrium partition coefficient σ of rigid macromolecules. It is found that the molecular size dependence of σ is quite different for the three solid phase elements. An approximate, but plausible expression for σ is also obtained for the linear flexible chain.