Polyelectrolyte-surfactant complexes and their influence on the wettability of different polymer surfaces

A novel method to modify the wettability of polymer surfaces is presented. It was found that the surface properties of polymers with different surface-free energies—polyamide 6.6, polypropylene, polyethylene and polystyrene—can be easily changed by a simple modification with premixed polyelectrolyte-surfactant complexes (PSCs). The modification effect can be significantly affected by the complex properties which are influenced by the type of surfactant and polyanion and their charge ratio in a mixture. Complexes having positive charge and low surface tension are most effective. All the complexes investigated show an interaction with polymer surfaces; however, the most effective modification was obtained with hydrophobic substrates such as polypropylene and polystyrene. In contrast to modification with the ‘pure surfactant’, the modification with PSC is persistent also after rinsing.