Free Energy for Confinement of a Single Polymer Chain

Recent years have seen a renewed interest on the properties of the confined polymers for their close connection to biological processes such as genome packaging in viral capsids and chaperone-assisted protein folding in bacterial cells. The thermodynamic properties of a confined single chain have been studied before by scaling analysis and computer simulations. However, a comprehensive understanding is yet emerging, especially in the limit of large polymer packing density as occurred in many biological systems. In this work, we use the polymer density functional theory (DFT) to study the structure and thermodynamic properties of single polymer chains in spherical cavities. At conditions accessible to molecular simulations or suitable for the scaling analysis, the theoretical predictions are in good agreement with established results.