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CPP: Chemische Physik und Polymerphysik
CPP 15: POSTER: Polymers and Biomaterials
CPP 15.13: Poster
Dienstag, 9. März 2004, 17:00–19:00, B
Grazing-incidence small-angle X-ray scattering on thin lamellar diblock copolymer films: Modelling the scattering cross section — •Christine M. Papadakis1, Peter Busch1, Markus Rauscher2, Detlef-M. Smilgies3 und Dorthe Posselt4 — 1Fakultät für Physik und Geowissenschaften, Universität Leipzig — 2MPI für Metallforschung, Stuttgart — 3CHESS, Cornell University — 4Roskilde University, Denmark
Grazing-incidence small-angle X-ray scattering (GISAXS) is a powerful method to elucidate the mesoscopic structures formed by thin polymer films. We have studied a series of thin films of lamellar polystyrene-polybutadiene (PS-PB) diblock copolymers. In this system, the lamellar orientation (parallel or perpendicular to the substrate) can be controlled by block copolymer molar mass [1].
For low angles of incidence, the scattering intensity is maximum and details are most pronounced. This results in short measuring times, thus allowing for time-resolved measurements as well [2]. Interpreting the two-dimensional GISAXS maps, the refraction of the X-rays at the surface of the polymer film as well as their reflection by the substrate need to be taken into account. This is possible by calculating the scattering cross section in the framework of the distorted-wave Born approximation. Both for the case of parallel and perpendicular lamellae, the model compares well with the experimental results.
[1] P. Busch et al., Macromolecules 36, 8717 (2003).
[2] D.-M. Smilgies et al., Synchr. Rad. News 15, 35 (2002).