Convoluted micellar morphological transitions driven by tailorable mesogenic ordering effect from discotic...

Area of Science:

• Materials Science
• Polymer Chemistry
• Supramolecular Chemistry

Background:

• Block copolymers self-assemble into nanostructures with tunable properties.
• Liquid crystalline mesogens introduce ordering effects but can lead to slow kinetics and metastable morphologies.
• Understanding self-assembly mechanisms is key to controlling nanostructure formation.

Purpose of the Study:

• To investigate the self-assembly behavior of liquid crystalline block copolymers with triphenylene discotic mesogens.
• To explore the influence of small-molecule dopants on self-assembly kinetics and morphology.
• To elucidate the underlying self-assembly mechanisms and their impact on nanostructure formation.

Main Methods:

• Synthesis of liquid crystalline block copolymers bearing triphenylene discotic mesogens.
• Solution self-assembly studies under varying conditions (undoped and doped).
• Morphological characterization using techniques like transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS).
• Self-seeding experiments to assess the influence of doping on assembly mechanisms.

Main Results:

• The block copolymer exhibits spontaneous multiple morphological transitions driven by intrinsic liquid crystalline ordering.
• Doping with small-molecule dopants dramatically accelerates morphological transitions and leads to exotic micelle formation.
• High doping levels shift the self-assembly mechanism from intramolecular chain shuffling to a nucleation-growth mode.
• Self-seeding experiments with high doping yield highly uniform fibrils.

Conclusions:

• The self-assembly of liquid crystalline block copolymers is highly sensitive to subtle ordering effects and external stimuli like doping.
• Doping provides a powerful strategy to control self-assembly kinetics, morphology, and mechanism.
• The shift to a nucleation-growth mechanism under high doping enables the production of uniform nanostructures, such as fibrils.