Resealing of Polyelectrolyte Capsules after Core Removal

Poly(styrene sulfonate) and poly(allylamine hydrochloride) layers have been adsorbed supplementarily on polyelectrolyte capsules. The permeability of the original capsules consisting of four layer pairs was of the order of 10^–5 m/s for fluorescein. They were also permeable for macromolecules. Polyelectrolyte layers adsorbed afterwards reduced the permeability by three orders of magnitude for small molecules. These findings are interpreted as a resealing of pores, induced by the osmotic stress during fabrication.