(204a) Ion Solvation And Its Effects On The Miscibility Of Binary Polymer Blends

We study the solvation of small ions in a binary blend of two homopolymers having different dielectric constants. The interplay between the energetic preference of ions to be solvated by the high dielectric constant component and the entropic preference to have ions evenly distributed results in non-trivial effects on the miscibility of the two polymers. We first consider the solvation of a single ion in the mixture and its effect on the local composition change using the Flory-Huggins-de Gennes free energy for the polymer blend. This single-ion information is then used to construct a bulk free energy valid for small ion concentrations, from which the shift in the spinodal and coexistence curve is calculated.