Dresden 2014 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 17: Transport and Confinement I

CPP 17.1: Hauptvortrag

Dienstag, 1. April 2014, 09:30–10:00, ZEU 260

Glassy dynamics of polymers in geometrical confinement: From nanometric layers to condensed isolated chains — •Friedrich Kremer — Institute of Experimental Physics I, University of Leipzig

The question on what length-scale molecular and especially glassy dynamics of polymers takes place is of fundamental importance and has multifold practical implications as well. Recent results based on Broadband Dielectric Spectroscopy for nanometric thin (>5 nm) layers of poly(styrene), poly(methylmethacrylate)and poly(cis-1,4-isoprene) will be presented, delivering the concurring result that deviations from glassy dynamics of the bulk never exceed margins of +/-3 K independent of the layer thickness, the molecular weight of the polymer under study and the underlying substrate. A further exciting perspective is the measurement of the dynamics of condensed isolated polymer chains. - The experiments lead to the conclusions that glassy dynamics takes place on the length-scale a few polymer segments (<0.5 nm) while the conformation of the chain as a whole is strongly modified due to geometrical confinement.

References: Tress, M. et al., Science 341, (6152) 1371-1374 (2013); Mapesa, E.U. et al., Soft Matter 9 (44), 10592-10598 (2013); Kremer, F., E.U. Mapesa, M. Tress, M. Reiche, "Molecular Dynamics of Polymers at Nanometric Length Scales: From Thin Layers to Isolated Coils" in: "Recent Advances in Broadband Dielectric Spectroscopy", Y. P. Kalmykov (Eds.), NATO Science for Peace and Security Series B: Physics and Biophysics, Chapter 12, Springer (2012)