Hierarchical 2D-1D micelles self-assembled from the heterogeneous seeded-growth of rod-coil block copolymers.

Abstract

Precise control of size and dimension is the key to constructing complex hierarchical nanostructures, particularly multi-dimensional hybrid nanoassemblies. Herein, we conducted Brownian dynamics simulations to examine the seeded-growth of rod-coil block copolymer assemblies and discovered that 2D-1D (disk-cylinder) hybrid micelles could be formed via liquid-crystallization-driven self-assembly (LCDSA). 2D nanodisk micelles with smectic-like LC cores served as seeds. After adding rod-coil block copolymers into the seed solution, the copolymers incorporated onto the 2D seed edges to generate junction points. Several cylindrical arms were formed from the elongation of junction points, resulting in 2D-1D multi-dimensional hybrid micelles. The structural transition of the micelle core from smectic-like (disk) to cholesteric-like (cylindrical arms) LC packing manners benefit from the fluidity of LC. Such a seeded-growth behavior simultaneously exhibits the features of heterogeneous nucleation and homogenous epitaxy growth. Intriguingly, the arms generate in sequence, and its junction position is in the para-position first, followed by ortho-position or meta-position, resembling the difference in the substituent activities on the benzene ring. These theoretical findings are consistent with experimental results, and provide explanations to some unaddressed issues in experiments. The obtained results also reveal that the hybrid micelles are a good stabilizer due to their high surface area and distinctive suspension behaviors.