Architectural effects on polymer complexation : influence of monomer sequence, polymer topology and electrostatics

This thesis addresses polymer complexation, which is based on specific interactions between different parts of the polymeric system. Electrostatically-driven polymer complexation and complexation driven by hydrogen bonding and/or van-der-Waals interactions (including dipolar interactions) are the two main aspects. The former one comprises interpolyelectrolyte complexation, as the co-assembly of oppositely charged polymers can lead to insoluble domains, useful for the preparation of micellar structures. We specifically address the influence of branching (topology) of one macroion on the resulting micellar morphologies. The use of so-called miktoarm star-shaped polymers (star-polymers with different arms) allow the facile preparation of Janus-like or vesicular interpolyelectrolyte complexes. Further, they can be employed in an electrochemically-induced vesicle formation, when the oppositely charged counterions are electroactive hexacyanoferrates, changing the interaction pattern by oxidation/reduction. Here, a more detailed picture on the electrochemical processes is drawn with help of thermo-responsive and charged microgels, allowing a distinction between different electron pathways. The second major aspect addresses the architectural requirements for an efficient intramolecular complexation between weakly interacting polymer partners. First, the influence of monomer sequence is investigated. Here, a statistical or alternating monomer sequence facilitates complexation between these weakly interacting monomers. In turn, block copolymers are beneficial for higher interaction energies. In between, miktoarm stars provide an efficient means to harvest complexation also in dilute solutions. This can be traced back to the high mutual segment densities within the miktoarm stars, which favour complexation. In the same line, interfaces can induce complexation for block copolymers by increasing locally the segment density of the weakly interacting partners, which would not show substantial complexation in solution. In sum, design parameters for the modulation of complexation are derived