Diblock Copolymer Surfactants in Immiscible Homopolymer Blends: Swollen Micelles and Interfacial Tension

Abstract

We consider the effect of micellization upon the equilibrium macroscopic interfacial tension between A- and B-rich phases in a ternary mixture of immiscible A and B homopolymer with an AB diblock copolymer surfactant, for systems in which spherical micelles can form in the A-rich phase. Self-consistent field theory (SCFT) has been utilized to calculate the critical micelle concentrations (cmc's) and macroscopic interfacial tensions. The behavior of the systems of nearly balanced copolymers, which tend to form highly swollen micelles, is discussed within the context of the Helfrich theory of bending elasticity, using elastic constants obtained from SCFT simulations of weakly curved monolayers.