Eur. Phys. J. E 34, 7 (2011)
https://doi.org/10.1140/epje/i2011-11007-x

Surface-induced breakout crystallization in cylinder-forming P(I-b-EO) diblock copolymer thin films

¹ Technische Universität München, Physikdepartment, Fachgebiet Physik weicher Materie/Lehrstuhl für funktionelle Materialien, James-Franck-Str. 1, 85747, Garching, Germany
² HASYLAB at DESY, Notkestr. 85, 22603, Hamburg, Germany
³ Fakultät für Physik und Mathematik, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, 79104, Freiburg, Germany
⁴ Fakultät für Biologie, Universität Bayreuth, Universitätsstr. 30, 95447, Bayreuth, Germany

papadakis@tum.de

Received: 2 September 2010
Accepted: 21 December 2010
Published online: 20 January 2011

Abstract

We have found very slow crystallization in thin films of cylinder-forming poly(isoprene-b -ethyleneoxide) (P(I-b -EO)) diblock copolymers with PEO being the minority block. The film was crystallized at room temperature after melting at 62 ^°C . Imaging methods were combined with X-ray reflectometry and grazing-incidence small-angle X-ray scattering and diffraction. Initially, hexagonally packed, amorphous PEO cylinders lie in the film plane. After 148 days, crystallized, finger-like terraces were observed over the entire film surface. The terrace height is 20% higher than the repeat distance in the as-prepared film. Thus, at the film surface, the cylinders have been destroyed by crystalline lamellae lying in the film plane. The PEO chain stems are perpendicular to the substrate surface and are once-folded and fully interdigitated. The substrate-near layers still consist of the hexagonally packed, amorphous PEO cylinders within the PI matrix.