title: Defect evolution in block copolymer thin films via temporal phase transitions.
abstract: We study the details of the defect dynamics in thin films of a cylinder-forming polystyrene-block-polybutadiene (SB) diblock copolymer melt. The high temporal resolution of in-situ scanning force microscopy (SFM) uncovers elementary dynamic processes of structural rearrangements on time scales not accessible so far. Short-term interfacial undulations and the formation of transient phases (spheres, perforated lamellae, and lamellae) are observed. We demonstrate that the well-known structural defects are annihilated by short-term phase transitions into what may be considered excited states. These temporary phase transitions are reproduced in simulations based on dynamic self-consistent field theory. We discuss the role of the observed structural evolution in the context of the equilibrium phase behavior in SB thin films.
authors.affiliation: Physikalische Chemie II, Universität Bayreuth, D-95440 Bayreuth, Germany. larisa.tsarkova@uni-bayreuth.de
authors.forename: Larisa
authors.initials: L
authors.lastname: Tsarkova
authors.forename: Andriana
authors.initials: A
authors.lastname: Horvat
authors.forename: Georg
authors.initials: G
authors.lastname: Krausch
authors.forename: Andrei V
authors.initials: AV
authors.lastname: Zvelindovsky
authors.forename: G J Agur
authors.initials: GJ
authors.lastname: Sevink
authors.forename: Robert
authors.initials: R
authors.lastname: Magerle