Regensburg 2010 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 38: Focus: Charge Effects in Soft and Biological Matter III (joint CPP, BP, ST)

BP 38.6: Vortrag

Freitag, 26. März 2010, 11:45–12:00, H45

Collapse of highly charged polyelectrolytes triggered by attractive dipole-dipole interactions — •Andrey Cherstvy — IFF-2, FZ Juelich

We study the collapse of flexible highly charged polyelectrolyte PE chains induced by attractive dipole-dipole interactions [1]. The latter emerge due to formation of dipoles between the chain monomers and counterions condensed on PE from solution. Using the statistics of slightly perturbed Gaussian polymers, we obtain the scaling relations for PE dimensions as a function of PE charge density in the limit of compacting chains. The results are in good agreement with the outcomes of MD simulations of collapse of flexible PEs with explicit counterions. Then, we analyze the results of MD simulations for complex formation by two highly charged PEs carrying opposite charges. We use the scaling arguments based on the picture of complexation of electrostatic blobs to rationalize the size of complexes of the two chains in the collapsed state. We also analyze PE linear charge densities required for the onset onto collapse. [1] A. Cherstvy, submitted to JPCB.