Segregation of Block Copolymer Micelles to Surfaces and Interfaces

Surface and interface segregation of block copolymer micelles in a model system has been observed. The distribution of a diblock copolymer within a high molecular weight homopolymer matrix phase was determined quantitatively by forward recoil spectrometry. Cross-sectional transmission electron microscopy showed that excess copolymer segregation to the homopolymer / homopolymer and homopolymer/ vacuum interfaces was due to the preferential segregation of block copolymer micelles to these interfaces. We argue that the segregation of block copolymer micelles is a manifestation of attractive interactions between polymer brushes, and between polymer brushes and a free surface, which are important in high molecular weight homopolymer matrices. © 1991, American Chemical Society. All rights reserved.