Effective-medium Gaussian-chain theory for semidilute polymer solutions confined to a slit

Theoretical formulation for the thermodynamics of a nondilute polymer solut ion in a confined space is presented. The interactions between polymer chai ns were taken into account as an effective potential field in which a chain of the Gaussian conformation grows. We determined the potential so that, w hen applied to the bulk solution, the theory reproduces the osmotic pressur e of the bulk solution calculated within renormalization group theory. The Green function for the polymer chains confined to a slit was calculated sel f-consistently, since the density profile obtained from the Green function determines the potential field within the slit. The chemical potential, the partition coefficient, the density profile, and the dimension of the polym er chain perpendicular to the slit walls were obtained as a function of the concentration for different slit widths. The results agree with those obta ined in the computer simulations. (C) 2001 American Institute of Physics.