Regensburg 2007 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 7: POSTER: INTERNAL SYMPOSIUM Scattering Experiments
CPP 7.8: Poster
Montag, 26. März 2007, 16:00–18:00, Poster B
Structure and changes of thin block copolymer films during vapor treatment — •zhenyu di1, christine papadakis1, dorthe posselt2, and detlef-m smilgies3 — 1Physikdepartment E13, TU München, 85747 Garching, Germany — 2IMFUFA, Roskilde University, Dänemark — 3CHESS, Cornell University, Ithaca NY, USA
The mesoscopic structures formed by diblock copolymers in thin film geometry are interesting for a variety of applications. However, self-assembly leads to domain structures with domain walls and defects. Vapor treatment has been shown to be an efficient way to increase the long-range order.
We have studied the structural changes in thin films of poly(styrene-b-butadiene) (PS-PB) diblock copolymers and their kinetics during vapor treatment. In this system, the initial lamellar orientation (parallel or perpendicular) can be controlled by the block copolymer molar mass [1]. We have investigated both initial orientations as well as the influence of the solvent selectivity and the film thickness. In-situ grazing-incidence small-angle x-ray scattering (GISAXS) is ideally suited because of its good time resolution (~sec) [2]. We found that in addition to swelling of the films, lamellar reorientation takes place on the time scale of minutes. Complex processes and transient states were encountered. In some cases, improved long-range order was achieved.
[1] P. Busch, D. Posselt, D.-M. Smilgies, C.M. Papadakis et al. Macromolecules 36, 8717 (2003) and Macromolecules, in press.
[2] D.-M. Smilgies, P. Busch, C.M. Papadakis, D. Posselt, Synchr. Rad. News 15(5), p. 35 (2002).