Berlin 2008 – wissenschaftliches Programm

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DS: Fachverband Dünne Schichten

DS 35: Nanostructured block copolymer films (SYSA 8)

DS 35.4: Vortrag

Donnerstag, 28. Februar 2008, 18:00–18:15, H 2032

Thin films of diblock copolymers having one crystalline block — •Charles Darko¹, Ioan Botiz², Günter Reiter², Dag W. Breiby³, Jens W. Andreasen⁴, Detlef-M. Smilgies⁵, Stephan V. Roth⁶, and Christine M. Papadakis¹ — ¹Physikdepartment E13, TU München — ²ICSI, CNRS, Mulhouse, France — ³Norwegian University of Science and Technology, Trondheim, Norway — ⁴Risø National Laboratory, Denmark — ⁵Cornell University, Ithaca, USA — ⁶HASYLAB at DESY, Hamburg

In thin films of symmetric poly(styrene-b-ethyleneoxide) (PS-b-PEO) diblock copolymers, the surface morphologies obtained are strongly influenced by the internal structural rearrangement within the films which are associated with different mechanisms of crystal growth of PEO. With grazing incidence small and wide angle X-ray scattering, we obtained information about the mesoscopic structures as well as the crystallite orientations within the thin films. We observed lamellae parallel to the substrate in all films, but the internal structure and the degree of preferred orientation depends strongly on crystallization temperature: When crystallized at 25^∘C, the c-axis is oriented at approximately 35^∘ with respect to the film normal with a broad distribution. At a crystallization temperature of 50^∘C, the c-axis becomes perfectly perpendicular to the substrate/film interface. The lamellar repeat distances increase with crystallization temperature. The information on the inner structures is compared to the surface textures measured by optical and atomic-force microscopy (AFM).