Berlin 2012 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
CPP: Fachverband Chemische Physik und Polymerphysik
CPP 1: Interfaces and Thin Films I
CPP 1.12: Vortrag
Montag, 26. März 2012, 12:45–13:00, C 130
In-situ study of structural changes in lamellar diblock copolymer thin films during heat treatment — •Alessandro Sepe1, Dorthe Posselt2, Jan Perlich3, Detlef-M. Smilgies4, and Christine M. Papadakis1 — 1TU München, Physikdepartment, Physik weicher Materie, Garching, Germany — 2Institute for Science, Systems and Models, Roskilde University, Denmark — 3HASYLAB at DESY, Hamburg — 4Cornell High-Energy Synchrotron Source (CHESS), Ithaca, U.S.A.
Diblock copolymer thin films are prominent candidates for a range of applications requiring nanostructured surfaces, such as nanoporous films. Thermal annealing has frequently been applied to remove defects and to improve the long-range order. Annealing temperature is a key parameter because it influences both, the interfacial tension between the two blocks and the polymer mobility. We investigate the mechanisms of structural changes induced by thermal treatment of thin films of poly(styrene-b-butadiene) having initially the perpendicular lamellar orientation. In-situ grazing-incidence small-angle X-ray scattering and VIS interferometry as well as ex-situ atomic force spectroscopy and X-ray reflectivity were used to monitor the changes. We have found that for annealing temperatures below the glass transition temperature of the PS block and subsequent cooling to room temperature, the lateral order is improved, whereas above, a random lamellar orientation and subsequent severe changes of the film structure are observed.