RAFT Synthesis and Self-Assembly of Free-Base Porphyrin Cored Star Polymers

Abstract EN

Reversible addition fragmentation chain transfer (RAFT) synthesis and self-assembly of free-base porphyrin cored star polymers are reported.

The polymerization, in the presence of a free-base porphyrin cored chain transfer agent (CTA-FBP), produced porphyrin star polymers with controlled molecular weights and narrow polydispersities for a number of monomers including N, N-dimethylacrylamide (DMA) and styrene (St).

Well-defined amphiphilic star block copolymers, P-(PS-PDMA)4 and P-(PDMA-PS)4 (P: porphyrin), were also prepared and used for self-assembly studies.

In methanol, a selective solvent for PDMA, spherical micelles were observed for both block copolymers as characterized by TEM.

UV-vis studies suggested star-like micelles were formed from P-(PS-PDMA)4, while P-(PDMA-PS)4 aggregated into flower-like micelles.

Spectrophotometric titrations indicated that the optical response of these two micelles to external ions was a function of micellar structures.

These structure-related properties will be used for micelle studies and functional material development in the future.