title: Influence of initial order on the microscopic mechanism of electric field induced alignment of block copolymer microdomains.
abstract: We investigate the mechanism of microdomain orientation in concentrated block copolymer solutions exposed to a dc electric field by in situ synchrotron small-angle X-ray scattering (SAXS). As a model system, we use concentrated solutions of a lamellar polystyrene-b-polyisoprene block copolymer in toluene. We find that both the microscopic mechanism of reorientation and the kinetics of the process strongly depend on the initial degree of order in the system. In a highly ordered lamellar system with the lamellae being aligned perpendicular to the electric field vector, only nucleation and growth of domains is possible as a pathway to reorientation and the process proceeds rather slowly. In less ordered samples, grain rotation becomes possible as an alternative pathway, and the process proceeds considerably faster. The interpretation of our finding is strongly corroborated by dynamic self-consistent field simulations.
authors.affiliation: Lehrstuhl für Physikalische Chemie II, Universität Bayreuth, Germany.
authors.forename: Kristin
authors.initials: K
authors.lastname: Schmidt
authors.forename: Alexander
authors.initials: A
authors.lastname: Böker
authors.forename: Heiko
authors.initials: H
authors.lastname: Zettl
authors.forename: Frank
authors.initials: F
authors.lastname: Schubert
authors.forename: Helmut
authors.initials: H
authors.lastname: Hänsel
authors.forename: Franz
authors.initials: F
authors.lastname: Fischer
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Weiss
authors.forename: Volker
authors.initials: V
authors.lastname: Abetz
authors.forename: A V
authors.initials: AV
authors.lastname: Zvelindovsky
authors.forename: G J A
authors.initials: GJ
authors.lastname: Sevink
authors.forename: Georg
authors.initials: G
authors.lastname: Krausch
mesh_terms: D004560:Electricity; D007700:Kinetics; D011108:Polymers; D053838:Scattering, Small Angle; D014961:X-Ray Diffraction
chemical_list: D011108:Polymers