Self Assembly of Polyferrocenylsilane (PFS) Block Copolymers

Block copolymers of polyferrocenylsilane (PFS), such as PFS-polyisoprene (PI) and PFS-polydimethylsiloxane (PDMS), are crystalline-coil block copolymers. When dissolved in a selective solvent for the non-PFS block, the block copolymer forms fiber like micelles with a semicrystalline PFS core and a solvent swollen corona. A unique feature of PFS block copolymer micelles is that they can be elongated, in a living manner, by adding more PFS block copolymer unimers. We have shown that the micelle formation is driven by the epitaxial growth of the semicrystalline PFS core. We have also demonstrated that this type of living, crystallization-driven growth offers exceptional potential for the controlled generation of complex and hierarchical micelle architectures. Since the late 1990ís, this project has been a collaboration between the Winnik group and the Manners group at the University of Bristol.

Self-Assembly Kinetics as a Route to Controlling the Morphology of Micelles

The seeded-growth kinetics of block copolymer unimers dominates their crystallization driven co-assembly behavior. One can manipulate the kinetics to control the growth sequence of unimers and thus the comicelle morphology. Patchy comicelles are formed when the growth rates of unimers are similar, while dissimilar growth rates lead to block comicelles.