The Phase Behaviors of A Polymer Solution Confined between Two Concentric Cylinders

A theoretical study on the phase behaviors of a polymer solution confined between two coaxial cylindrical walls is presented. For the case of a neutral inner cylinder, the spinodal point derived through the Gaussian fluctuation theory is confinement-independent because of the existence of a free dimension in the system. The kinetic analysis indicates that the fluctuation modes always have a component of a plane wave along the axial direction, which can lead to the formation of a periodic-like concentration pattern. On the other hand, the equilibrium structure of the system is obtained by using the self-consistent mean-field theory (SCMFT) and the interplay between the "wetting" phenomenon and the phase separation is observed by modifying the property of the inner cylinderical wall.