Convoluted micellar morphological transitions driven by tailorable mesogenic ordering effect from discotic mesogen-containing block copolymer.

Abstract

Solution-state self-assemblies of block copolymers to form nanostructures are tremendously attractive for their tailorable morphologies and functionalities. While incorporating moieties with strong ordering effects may introduce highly orientational control over the molecular packing and dictate assembly behaviors, subtle and delicate driving forces can yield slower kinetics to reveal manifold metastable morphologies. Herein, we report the unusually convoluted self-assembly behaviors of a liquid crystalline block copolymer bearing triphenylene discotic mesogens. They undergo unusual multiple morphological transitions spontaneously, driven by their intrinsic subtle liquid crystalline ordering effect. Meanwhile, liquid crystalline orderedness can also be built very quickly by doping the mesogens with small-molecule dopants, and the morphological transitions are dramatically accelerated and various exotic micelles are produced. Surprisingly, with high doping levels, the self-assembly mechanism of this block copolymer is completely changed from intramolecular chain shuffling and rearrangement to nucleation-growth mode, based on which self-seeding experiments can be conducted to produce highly uniform fibrils.