Defect evolution in block copolymer thin films via temporal phase transitions.
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.
Tsarkova
Larisa
L
Physikalische Chemie II, Universität Bayreuth, D-95440 Bayreuth, Germany. larisa.tsarkova@uni-bayreuth.de
Horvat
Andriana
A
Krausch
Georg
G
Zvelindovsky
Andrei V
AV
Sevink
G J Agur
GJ
Magerle
Robert
R