Clustering in metallo-supramolecular micelles

Clustering and aggregation of PS20-[Ru]-PEO70 copolymers (where PS = polystyrene and PEO = poly(ethylene oxide)) was investigated. Aq. micelles of the copolymer exhibited complicated assocn. behavior, and were spherical in water. The micelles aggregated into small polydisperse clusters with an av. size of .apprx.60-70 nm. A small no. of large clusters was also obsd. The 3 types of species were visualized with TEM. The formation of aggregated species of metallo-supramol. micelles was related to ionic interactions among the micelles, as evidenced by the effect of added salt which is obviously able to dissoc. the small clusters into individual micelles. The bulky \\"hydrophobic\\" PF6- counter-anion could play an essential role in this phenomenon and act as a \\"glue\\" for the micelles.