Synthesis and characterization of metallo-supramolecular micelles

Two different metallo-supramolecular amphiphilic block copolymers have been synthesized, using a hydrophilic poly(ethylene oxide) block connected through a bis-(2,2':6'2"-terpyridine-ruthenium) complex either to a hydrophobic polystyrene or to a poly(ethylene-co-butylene) block. These copolymers were used to prepare aqueous micelles. The morphological characterization of the metallo-supramolecular micelles was performed by dynamic light scattering and transmission electron microscopy. Besides individual micelles, larger structures were also observed by these two independent techniques. The larger structures were the result of aggregation of individual micelles. In addition, the influence of the ionic strength of the medium was investigated. Although the metallo-supramolecular copolymers do not contain charged blocks, the corresponding micelles behaved as polyelectrolyte-like micelles. This behaviour was attributed to the presence of NaCl ions, strongly associated to the poly(ethylene oxide) blocks. This was evidenced by transmission electron microscopy, that revealed the presence of the salt in the metallo-supramolecular micelles. (C) 2003 Society of Chemical Industry.