• Van Bürck, U.
• Kampmann, R.
• Kaune, G.
• Moulin, J.-F.
• Rauscher, M.
• Haese-Seiller, M.
• Metwalli, E.
• Haese, Martin
• Müller-Buschbaum, Peter
• Ruderer, M. A.

Abstract

<jats:p>The depth-dependent morphology of the microphase separation structure in thin block copolymer films is examined using non-destructive time-of-flight grazing-incidence small-angle neutron scattering. The structure of a cylinder-forming diblock copolymer, polystyrene(deuterated)-<jats:italic>block</jats:italic>-polyisoprene, in contact with either a low- or a high-energy substrate surface is investigated. A systematic identification of the components of the polymer film at different depths is achieved by utilizing the material characteristic Yoneda peak. For the polymer film attached to the low-surface-energy aminosilane-coated substrate, a morphology transition from lamellar at the substrate–polymer interface,<jats:italic>via</jats:italic>perforated lamellar in the film bulk, to an ill-defined structure at the polymer–air interface is observed. This phase transition along the film normal is due to the competition between the surface-induced morphological changes and the stable cylindrical bulk morphology of the diblock copolymer. In contrast, on the high-energy surface no pronounced ordering is found for the applied conditions.</jats:p>

Topics

• impedance spectroscopy
• morphology
• surface
• phase
• phase transition
• forming
• copolymer
• block copolymer
• small-angle neutron scattering