Dresden 2014 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 37: Poster Session 2

CPP 37.51: Poster

Wednesday, April 2, 2014, 15:00–19:00, P3

AFM Observation of Heterogeneous Nucleation in Epitaxially Crystallized Polymers — Ann-Kristin Löhmann, •Martha Schulz, Jana Rüdel, Thomas Henze, and Thomas Thurn-Albrecht — Institut für Physik, Martin-Luther-Universität Halle-Wittenberg

We present a microscopic study of heterogeneous nucleation in epitaxially crystallized polymers. Instead of randomly occuring nuclei leading to a spherulitic growth, we find a different mechanism in the case of epitaxy. Crystallization starts from an ordered interfacial layer that is stabilized above the bulk melting point. This layer wets the interface and acts as a nucleus which induces the unusual highly oriented lamellar structure of the crystalline film. Ultrathin films of LLDPE, HDPE and PCL crystallized epitaxially on graphite were studied at temperatures close to the polymer melting point. The AFM measurements at high temperatures were performed in the net-attractive oscillation state [1] of Intermittent Contact Mode. The stabilized interface layer can be found in all of the studied systems with differences in morphology, thickness and stabilized temperature range.

[1] T. Henze, K. Schröter, and T. Thurn-Albrecht, Nanotechnology 23, 245702 (2012).