Dresden 2003 – wissenschaftliches Programm

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CPP: Chemische Physik und Polymerphysik

CPP 22: POSTER C

CPP 22.7: Poster

Donnerstag, 27. März 2003, 12:00–14:00, ZEU/250

CONFORMATIONAL TRANSITIONS OF SINGLE POLYELECTROLYTE MOLECULES — •Ganna Gorodyska, Anton Kiriy, Sergiy Minko, and Manfred Stamm — Institut fuer Polymerforschung Dresden, Hohe Strasse 6, 01069 Dresden

We show that hydrophobic flexible polyelectrolyte molecules of poly(2-vinylpyridine) and poly(methacryloyloxyethyl dimethylbenzyl ammonium chloride) are trapped and frozen due to adsorption on the mica surface and the observed with AFM single molecule structures reflect the molecular conformation in solution. Increase of ionic strength of the solution induces the cascade of abrupt conformational transitions due to the intra-chain segregation from elongated coil to compact globule conformations through intermediate pearl necklace globule conformations with different amount of beads per chain. Length of the necklaces and number of beads decreases, while diameter of beads increases with the increase of ionic strength. Co-existence at the same time of extended coils, necklaces with different amount of beads and compact globules indicates the cascade of the first-order-type phase transitions.