Dresden 2009 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 12: Poster I
DY 12.21: Poster
Dienstag, 24. März 2009, 14:30–16:30, P1A
Pseudo-knots in helical structures — Fernao Vistulo de Abreu1, Ricardo Dias1, and •Christian von Ferber2,3 — 1Department of Physics, Aveiro University, Portugal — 2Applied Mathematics Research Centre, Coventry University, UK — 3Physikalisches Institut, Universität Freiburg
It is generally accepted that physical entanglements are essential to explain some mechanical properties of polymers, like viscoelasticity. The current view is that entanglements behave as dynamic links that are destroyed and created in time. It is less clear whether entanglements could alternatively produce local and stable links, with similar effects to chemical bonds. Here we show that local and stable entanglements, that we call physical pseudo-knots, exist and are formed with high probability in helical structures. The energies required to create and destroy physical pseudo-knots can differ by at least one order of magnitude. Together with their localized nature this makes them controllable, opening the possibility for a wide range of applications in material science, nano- and biotechnology. Physical pseudo-knots may also have implications for living systems, that may use them, or try to avoid them and hence be related to disease. [Soft Matter 4:731 (2008)]