Wolf, B.A.

"Binary Interaction Parameters, Ternary Systems: Realistic Modeling of Liquid/Liquid Phase Separation"

Macromolecular Theory and Simulation 2009, 18, 30-41.

Abstract: The present modeling considers two specific features of polymers explicitly: Chain connectivity and their ability to respond to changes in the molecular environment by conformational reorientation. So far this approach has been applied to polymer solutions in single solvents. Here it is generalized to arbitrary molecular weights of the components and the number of parameters is reduced to two per binary system. The calculation of the Gibbs energies of the ternary mixtures accounts for the composition dependencies of the binary interaction parameters. The following phenomena are reproduced realistically for polymer solutions in a mixed solvent and for solutions of two polymers in a common solvent: Simplicity (gradual transitions between the miscibility gaps of the binaries), co-solvency (complete miscibility of one component with mixtures of the other two components only), and co-non-solvency (islands of immiscibility despite totally miscible binaries). The results nourish the hope that the new approach is capable of modeling phase diagrams for ternary systems by means of binary interaction parameters, without the necessity to introduce ternary ones.

preprint number: 293