As shown in Figure 4, the structures are approximately 23 nm in diameter and are of narrow size distribution. SCK's deposited on mica exhibited a tendency to organize into relatively regular aggregates, similar to those observed for polymer latex particles. The ability of 6 to form monolayers of such aggregates indicates that cross-linking of the exterior layer proceeds only through intramicellar polymerization with little or no intermicellar reaction. This observation is consistent with the apparent retention of water solubility for 6 . AFM studies support the presence of PVP on the surface due to the SCK's being more easily deformed than the surface of PS latex particles under the lateral force exerted by the probe tip.
Further characterization is in progress.
For instance, our recent work focuses on controlling the size of the SCK's through variances in block lengths, quaternization percentages, and quaternizing groups. Potential applications are also being explored including encapsulation and carrier systems, water treatment, catalysis, etc. Ardoin, N. and Astruc, D. Bulletin de la Societe Chim. Advances in Dendritic Macromolecules, Ed. G. R. Newkome, JAI Press, Greenwich, Connecticut, 1994-5, Vol.