title: Lateral versus perpendicular segregation in mixed polymer brushes.
abstract: Grafting of incompatible polymers on a substrate prevents macrophase separation and the chains self-assemble laterally. Mixed brushes are exposed to different solvents and the morphology is observed via atomic force and x-ray photoemission microscopy. In a nonselective solvent the different species segregate into parallel cylinders ("ripple structure"). Upon exposure to a selective solvent, we encounter a transition to a "dimple" structure, in which the unfavored component forms clusters. Simultaneously, we observe an enhanced perpendicular segregation. The experimental observations are compared to self-consistent field calculations, where qualitative agreement is found.
authors.affiliation: Institut für Polymerforschung Dresden e.V., Postfach 12 04 11, D-01005 Dresden, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Minko
authors.forename: M
authors.initials: M
authors.lastname: Müller
authors.forename: D
authors.initials: D
authors.lastname: Usov
authors.forename: A
authors.initials: A
authors.lastname: Scholl
authors.forename: C
authors.initials: C
authors.lastname: Froeck
authors.forename: M
authors.initials: M
authors.lastname: Stamm