POLYMERIC BICONTINUOUS MICROEMULSIONS

High molecular weight block copolymers can be viewed as macromolecular surfactants when blended with thermodynamically incompatible homopoly mers. This Letter describes the formation of polymeric bicontinuous mi croemulsions in nurtures containing a model diblock copolymer and two homopolymers. Although we attribute development of this equilibrium mo rphology to the effects of fluctuations, mean-field theory provides a quantitative strategy for preparing the bicontinuous state at blend co mpositions near an isotropic Lifshitz point.