Synthesis and solution self-assembly of block copolymers with a gradient, crystallizable polyferrocenylsilane core-forming metalloblock

Well-defined block copolymer micelles can be generated by crystallization-driven living self-assembly processes using highly asymmetric diblock copolymers, typically comprised of a much shorter crystalline core-forming polyferrocenylsilane (PFS) block and a longer corona-forming coblock. In order to better understand the underlying mechanism and broaden the scope of crystallization-driven self-assembly processes, further detailed studies of crystalline-coil block copolymers with controlled variations in the crystalline core structure are needed. Here we report studies of asymmetric PI-b-P(FDMS-co-FDES) diblock terpolymers (PI = polyisoprene), where the crystallizable core contains a mixture of ferrocenyldimethylsilane (FDMS) and ferrocenyldiethylsilane (FDES) repeating units. The core-forming metalloblock exhibits an almost gradient structure, as revealed by kinetic studies. Cylindrical micelles were obtained in n-hexane, and were characterised by TEM and WAXS, and the results are compared with the self-assembly behaviour of structurally similar PI-b-PFDMS and PI-b-PFDES diblock copolymers.