Synthesis and Solution Self-Assembly of Polyisoprene-block-poly(ferrocenylmethylsilane): A Diblock Copolymer with an Atactic but Semicrystalline Core-Forming Metalloblock

Polyisoprene-b-poly(ferrocenylmethylsilane) (PI-b-PFMS) copolymers, containing the atactic but semicrystalline PFMS block, have been prepared by sequential anionic polymerization of isoprene andmethyl[1]silaferrocenophane. The reactionto formthemetalloblock isnot living in nature, but still enables three copolymers to be prepared (PI35-b-PFMS5, PI200-b-PFMS10, and PI247-b-PFMS23) with relative narrow molar mass distributions (polydispersity < 1.3). The self-assembly of all three materials is studied in PI selective n-alkanes and found to afford lenticular platelets, tapered cylindrical micelles, and regular cylinders, as the length of the PFMS block increased. PI200-b-PFMS10 micelles could be increased in length by self-seeding a sample of shortmicelles at temperatures of 90 C and above; however, this process also results in an increase in width. Addition of a solution of PI247-b-PFMS23 copolymer to preformed seed micelles also results in an increase in length, although growth is not linearly related to the amount of copolymer added beyond 600 nm.