Dresden 2006 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
SYSS: Structure Formation and Self-Organization in non-equilibrium Systems
SYSS 3: Structure Formation and Self-Organization in non-equilibrium Systems - Poster
SYSS 3.3: Poster
Donnerstag, 30. März 2006, 16:00–18:00, P1
Transient states during vapor treatment of thin, lamellar diblock copolymer films — •C.M. Papadakis1, D. Posselt2, and D.-M. Smilgies3 — 1Physikdepartment E13, Technische Universität München, James-Franck-Str. 1, D-85747 Garching — 2IMFUFA, Roskilde University, Denmark — 3Cornell University, Ithaca NY, USA
Diblock copolymers in the melt spontanously self-organize into mesoscopically ordered structures. In order to understand their response to changes of the environment, in-situ and real-time methods are of great value. We have performed time-resolved grazing-incidence small-angle X-ray scattering (GISAXS) measurements on thin films of lamellar poly(styrene-b-butadiene) diblock copolymers having initially the lamellae parallel or perpendicular to the substrate surface.
We have found that the response to toluene vapor is very different for the two lamellar orientations. Films with the perpendicular orientation reacted at once, and continuous swelling of the film occurred on the time scale of minutes. Tilting of lamellar stacks was observed as well, however, during drying, the perpendicular orientation was recovered [1]. In films with the initially parallel orientation, the lamellae swell significantly, but the lamellar interfaces remain flat. After a few minutes, undulations of the lamellar interfaces are observed, which, however, diminish again after approx. one minute, and the initial lamellar thickness is recovered. These observations point to an instability during the swelling process.
[1] D.-M. Smilgies, P. Busch, C.M. Papadakis, D. Posselt, Synchr. Rad. News 15, no. 5, S. 35 (2002).