Synthesis of fullerene-containing poly(ethylene oxide)-block-polystyrene as model shape amphiphiles with variable composition, diverse architecture, and high fullerene functionality

A series of [60]fullerene (C-60)-containing poly(ethylene oxide)-block-polystyrene (PEO-b-PS) with various numbers and different locations of C-60 along the polymer chains were designed and synthesized via a combination of "click" chemistry and living/controlled polymerization techniques such as anionic polymerization, atom transfer radical polymerization, and reversible addition-fragmentation chain transfer polymerization. One C-60 was tethered either to the end of a PS block (PEO-b-PS-C-60) or at the junction point between PS and PEO blocks [PEO-(C-60)-PS]; while multiple C(60)s could be attached randomly along the PS block (PEO-b-PS/C-60). The reaction conditions were carefully controlled to ensure a quantitative C-60 functionality at precise locations in the case of PEO-b-PS-C-60 and PEO-(C-60)-PS and to avoid crosslinking in the synthesis of PEO-b-PS/C-60. The results have implications in the precision synthesis of fullerene polymers in general. These C-60-containing diblock copolymers possess different composition, diverse architecture, and high fullerene functionality. They can serve as model "shape amphiphiles" for the construction of complex hierarchical structures via the interplay between C-60-C-60 aggregation and block copolymer self-assembly/micro-phase separation.