Synthesis and crystallization-driven solution self-assembly of polyferrocenylsilane diblock copolymers with polymethacrylate corona-forming blocks

In order to increase the range of coronal chemistries available for crystallization-driven self-assembly protocols a series of highly asymmetric diblock copolymers comprising a crystallizable polyferrocenyldimethylsilane (PFS) block and a polymethacrylate coblock (poly(tert-butylmethacrylate) (PtBMA), poly(n-butylmethacrylate) (PnBMA), and poly(N,N-dimethylaminoethylmethacrylate) (PDMAEMA), block ratios PFS core : corona = 1 : 14–1 : 21) were synthesized by sequential living anionic polymerization. Self-assembly of these block copolymers in acetone yielded cylindrical micelles with a crystalline PFS core (confirmed by wide-angle X-ray scattering) and a polymethacrylate corona. The cylindrical micelles were fragmented by sonication and the short micelles were successfully used as “seed initiators” to grow longer monodisperse cylindrical micelles with controlled lengths from added unimers via crystallization-driven living self-assembly. Block co-micelles were also prepared by the sequential addition of unimers with a different coronal block to pre-existing cylinders.