Dresden 2006 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 24: POSTER Microfluidics
CPP 24.16: Poster
Donnerstag, 30. März 2006, 17:00–19:00, P2
Simple Method for the Stretching and Alignment of Single Adsorbed Synthetic Polycations — •Vera Bocharova1, Anton Kiriy1, Manfred Stamm1, Francois Stoffelbach2, Robert Jérôme2, and Christophe Detrembleur2 — 1Leibniz Institute of Polymer Research Dresden, D-01069 Dresden (Germany) — 2Center for Education and Research on Macromolecules (CERM), University of Liege, Sart-Tilman, B6, 4000 Liege, Belgium
It was found that positively charged macromolecules co-deposited with octylamine (OA) onto mica appear in a considerably more stretched conformation compared to adsorption onto untreated mica. Furthermore, the molecular thickness is considerably larger whenever the macromolecules are co-deposited with OA, which indicates a change in the local conformations of the chains and the orientation of their side-groups with respect to the substrate. These observations can be explained by the formation of an ultra-thin liquid-like film of OA onto mica that decreases the surface energy, weakens the interactions of the macromolecules with the surface and allows them to be stretched. The contour length and molar mass for the stretched macromolecules can be directly measured. The increase in the molecular height in case of co-deposition with OA drastically improves the molecular resolution, makes even ultra-thin polycations detectable and thus extends significantly the range of objects, which can be involved in single-molecule experiments.