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CPP: Chemische Physik und Polymerphysik

CPP 17: Physics of polymers I

CPP 17.5: Vortrag

Dienstag, 8. März 2005, 10:45–11:00, TU C130

Simulations and experiments of star-like polylectrolytes — •Arben Jusufi — a

We present a study of star-like polyelectrolyte systems (PE-stars) which consist of polyacrylic acid chains attached to a common cyclodextrine core, which size is microscopic in comparison to the extension of the PE-star (ca. 20nm). We have carried out theoretical investigations, computer simulations and experimental studies in order to determine the osmotic coefficient, effective interactions, and structural correlations of the system. First experimental results for the osmotic coefficient (which gives the ratio between the measured osmotic pressure of the counterions to the corresponding ideal osmotic pressure) of PE-stars in the dilute limit [1] has been shown to be almost constant over a wide range of PE-star concentration. This is confirmed theortically, and by recent results obtained from Molecular Dynamics simulations, as was presented in Ref. [2]. Results for structural correlations are additionally compared with anomalous small angle X-ray scattering (ASAXS). These experiments offer novel insight into the counterion distribution of PE-stars.

[1] X. Guo and M. Ballauff, Phys. Rev. E 64, 051406 (2001); B. Das, X. Guo and M. Ballauff, Progr. Colloid Polym. Sci. 121, 34 (2002). [2] A. Jusufi, C. N. Likos, and H. Löwen, Phys. Rev. Lett. 88, 018301 (2002); J. Chem. Phys. 116, 11011 (2002).