Precisely Prepared Hierarchical Micelles of Polyfluorene-block-Polythiophene-block-Poly(phenyl isocyanide) via Crystallization-Driven Self-Assembly

Abstract

The precise preparation of hierarchical micelles is a fundamental challenge in modern materials science and chemistry. Herein, poly(di-n-hexylfluorene)-block-poly(3-tetraethylene glycol thiophene) (poly(1_m-b-2_n)) diblock copolymers and polyfluorene-block-polythiophene-block-poly(phenyl isocyanide) triblock copolymers were synthesized using a one-pot process via the sequential addition of corresponding monomers using a Ni(II) complex as a single catalyst for living/controlled polymerization. The crystallization-driven self-assembly of amphiphilic conjugated poly(1_m-b-2_n) led to the formation of nanofibers with controlled lengths and narrow dispersity. The block copolymers exhibited white, yellow, and red emissions in different self-assembly states. By using uniform poly(1_m-b-2_n) nanofibers as seeds, introducing the polyfluorene-block-polythiophene-block-poly(phenyl isocyanide) triblock polymer as a unimer in the seed growth process, and adjusting the structure of the poly(phenyl isocyanide) block and the polarity of self-assembly solvent, A−B−A triblock micelles, multiarm branched micelles, and raft micelles were prepared.