Cryo-TEM of polyelectrolyte-micelle complexes

Cryo-TEM was carried out on samples containing polyelectrolyte-micelle complexes, formed by combining poly(diallyldimethylammonium chloride)(PDADMAC), a strong cationic polyelectrolye, with oppositely charged mixed micelles of sodium dodecyl sulfate (SDS) and nonionic Triton X-100 (TX100), in 0.40 M NaCl. Complexation appears to involve the formation of micelle-rich regions, presumably within the domains of polymer chains, without any particular organization or restructuring of the micelles. At polymer concentrations(C-P) less than or equal to 0.4 g/L, the observation of such clusters with dimensions as low as 50 nm suggests that intrapolymer complexes may exist at low C-P. With increasing polymer concentration, aggregates grow in size, with dimensions that indicate the involvement of many polymer chains. Upon increase in the ratio of SDS:TX100, the system coacervates, and the micelle/polymer-rich phase forms a continuous matrix. (C) 1997 Academic Press.