Dresden 2009 – wissenschaftliches Programm
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SYSO: Symposium Self-organizing Surfaces and Interfaces
SYSO 3: Self-Organizing Surfaces and Interfaces - Posters
SYSO 3.8: Poster
Mittwoch, 25. März 2009, 17:30–19:30, P3
Polymer brushes as self-organized surfaces — •Jens-Uwe Sommer1, Holger Merlitz1,2, and Gui-Li He3 — 1Leibniz Institute of Polymer Research, Hohe Strasse 6, D-01069 Dresdem, Germany — 2Department of Physics and ITPA, Xiamen University, Xiamen 361005, P.R. China — 3Institut für Theoretische Physik II, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
We propose a novel principle to build reversibly switchable polymer brushes based on molecular dynamics simulations. Here we use the interplay between the sharp concentration profile of densely grafted brushes and the effect of modified end-groups. We show that bulky end-groups display a strong tendency to localize on top of the polymer brush (“active” state of the coating). When the environment is changing to disfavor the end-groups (exposed to poor solvent), however, they retreat into the brush layer which turns the coating into a “passive” state. At high grafting densities the chains are highly stretched and the entropic difference between the active (stretched) and the passive (coiled) state is large leading to a sharp transition by changing the parameters of the environment (temperature, solvent quality) thus leading to an efficient switching behavior.