Complex coacervation core micelles as anti-fouling agents on silica and polystyrene surfaces

The adsorption of mixtures of a diblock-co-polymer with a negatively charged block and a neutral, hydrophilic block and an oppositely charged homopolymer on anionic and hydrophobic surfaces was studied with reflectometry. It turned out that the adsorbed mass is at a maximum when the number of cationic and anionic polyelectrolyte groups is equal. In bulk solution, the components form micelles at this composition. The thickness of the layers was in the order of the micellar radius in bulk solution, i.e. 25 nm. The adsorption kinetics are sensitive to block lengths of the diblock-co-polymer. The adsorbed layers were stable with respect to solvent exposure and even 1 M ionic strength could not completely erode the layers. The layers dramatically influenced the functionality of the surface, as they acted as excellent anti-fouling agents versus protein adsorption.