Statistical mechanics of charged polymers in electrolyte solutions: A lattice field theory approach

The lattice field theory approach to the statistical mechanics of a classic al Coulomb gas [R.D. Coalson and A. Duncan, J. Chem. Phys. 97, 5653 (1992)] is generalized to include charged polymer chains. Saddle-point analysis is done on the functional integral representing the partition function of the full system. Mean-field level analysis requires extremization of a, real-v alued functional which possesses a single minimum, thus guaranteeing a uniq ue solution. The full mean-field equations for such a coupled system are de rived, as well as the leading tone-loop) fluctuation corrections. Two diffe rent numerical real-space lattice procedures are developed to implement the generalized theory; these are applied to the problem of a charged polymer confined to a spherical cavity in an electrolyte solution. The results prov ide insight into the physics of confined polyelectrolytes. [S1063-651X(99)1 0709-8].