Dresden 2006 – scientific programme

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CPP: Chemische Physik und Polymerphysik

CPP 5: Polyelectrolytes

CPP 5.1: Talk

Monday, March 27, 2006, 14:30–14:45, ZEU 160

Fluctuation and correlation effects in charged macromolecular systems studied by molecular dynamics simulations — •Arben Jusufi and Matthias Ballauff — Physikalische Chemie I, Universität Bayreuth, 95440 Bayreuth, Germany

We have perfomed MD simulations of a charged macroion surrounded by counterions. Various scattering contributions result from correlations between counterions, macroion, and between both of them. Experimentally, these scattering contributions can be measured by anomalous small-angle X-ray scattering (ASAXS) experiments. As a result the cross-correlation between the rigid macroion and counterions yields always a meanfield expression for the counterion density distribution even if the counterions exhibit correlated fluctuations. In contrast, in star-like polyelectrolytes, representing a fluctuating macroion, meanfield approximations are valid only if the functionality is sufficiently high. A systematic investigation of the strength of correlated fluctuations and their effect in scattering intensities is demonstrated for these systems.