Theoretical investigation of ordering and complexation in solutions of polyelectrolytes
FacultiesFakultät für Naturwissenschaften
LicenseStandard (Fassung vom 03.05.2003)
The PhD thesis is dedicated to the theoretical investigation of two effects taking place in the ion-containing polymeric systems, namely, nematic ordering in solutions of rodlike polyelectrolytes and complexation in solutions of oppositely charged polyelectrolytes taking into account the effect of charge inversion (overcharging) of macroions. The correlation free energy of electrostatic interactions in solutions of rodlike polyelectrolytes was calculated within the framework of the Debye-Hueckel approach accounting for the many-body Coulomb interactions. The phase diagram of the system was obtained. A combination of the mean-field theory and the random phase approximation was used for a spherical penetrable microgel particle overcharged by oppositely charged multiarm star polyelectrolytes in dilute solution. The overcharging was shown to occur due to the gain in the electrostatic self-energy and in the elastic free energy of the star macromolecules, while counterions can either promote or suppress the effect. The same combination of the mean-field theory and the random phase approximation was used to describe the complexation in solutions of oppositely charged polyelectrolytes with the asymmetric content of positively and negatively charged chains. The phase diagram of the system was calculated. It has been shown that "excess" polyions coexisting with small neutral complexes at very small polymer concentrations can first aggregate into big spherical clusters with the following formation of cylindrical and lamellar structures at the increase of polymer concentration.
Subject HeadingsPolyelektrolyt [GND]
Drug delivery systems [MeSH]