Dresden 2003 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 22: POSTER C
CPP 22.43: Poster
Donnerstag, 27. März 2003, 12:00–14:00, ZEU/250
Surface and inner film structures in thin diblock copolymer films - a combined AFM and GISAXS study — •Peter Busch1, Detlef-M. Smilgies2, Dorthe Posselt3, Friedrich Kremer1 und Cristine M. Papadakis1 — 1Faculty of Physics, University of Leipzig — 2CHESS, Cornell University — 3Roskilde University, Denmark
Thin block copolymer films can be used for surface patterning on a submicrometer length scale, because of their ability to self-organize into microphase separated structures. One of the major difficulties is the control of the orientations of the structures formed. In many lamellar diblock copolymer films [1], the surfaces are selective to one of the two blocks, leading to a parallel orientation of the lamellae with respect to the film surfaces.
We show that in case of weak interactions of both blocks with the two surfaces, different lamellar orientations can be achieved, depending on molar-mass. This has been realized with a series of lamellar polystyrene-polybutadiene (PS-PB) diblock copolymers. Whereas films from low molar mass samples prefer a lamellar orientation parallel to the film surfaces, the lamellae are perpendicular in high molar mass samples. This has been found by combining atomic force microscopy (AFM) and grazing-incidence small-angle X-ray scattering (GISAXS), which allows a global description of the film structure [2]. We discuss the factors being at the origin of the molar mass dependence of the lamellar orientation.
[1] M.J. Fasolka and A.M. Mayes, Annu. Rev. Mater. Res., 31, 323 (2001). [2] D.-M. Smilgies, P. Busch, D. Posselt and C.M. Papadakis, Synchrotron Radiation News, 15, 35 (2002).