Distribution of a polymer chain between two interconnected spherical cavities*

Abstract

The equilibrium distribution of a polymer chain between two interconnected spherical cavities (a small one with radius R s and a large one with radius R l) is studied by using Monte Carlo simulation. A conformational transition from a double-cavity-occupation (DCO) state to a single-cavity-occupation (SCO) state is observed. The dependence of the critical radius of the small cavity (R sC) where the transition occurs on R l and the polymer length N can be described by R sC ∝ N 1 / 3 R l 1 − 1 / 3 ν with ν being the Flory exponent, and meanwhile the equilibrium number (m s) of monomers in the small cavity for the DCO phase can be expressed as m s = N/((R l/R s)3 + 1), which can be quantitatively understood by using the blob picture. Moreover, in the SCO phase, the polymer is found to prefer staying in the large cavity.