Surface texture of poly(styrenesulfonate sodium salt) and poly(diallyldimethylammonium chloride) micron-sized multilayer capsules: A scanning force and confocal microscopy study

Ultrathin polyelectrolyte capsules fabricated by stepwise assembly of poly( styrenesulfonate Sodium salt) and poly(diallyldimethylammonium chloride) ar e examined by confocal laser scanning microscopy and scanning force microsc opy. The capsule surface is composed of grains of 124 +/- 10 nm in diameter with a roughness of similar to 13 nm. These grains are formed by laterally segregated polyelectrolyte complexes. Osmotically and annealing-induced ca psule swelling facilitated further grain segregation together with a capsul e surface area increase. Incubation in salt solution induced capsule shrink ing and grain aggregation.