November 28, 2023

Volume 56, Issue 22

Pages 9031-9298

Rapid Assembly of Bottlebrush Random Copolymers into Nanostructured Colloids with Tunable Morphologies

Hierarchically structured polymeric colloids have shown great promise for diverse applications in particle-based technologies, but less emphasis has been placed on reducing the preparation time. Here, we present a rapid production of various nanostructured polymeric colloids by confined self-assembly of high-molecular-weight bottlebrush random copolymers (BRCPs) in evaporative emulsion droplets. BRCPs with polystyrene and poly(dimethyl siloxane) as two different side chains were used as a model polymer to elucidate their potential for the rapid generation of nanostructured particles. By rapid evaporation of emulsion solvent, symmetric BRCPs quickly assembled into onion-like particles with well-ordered concentric lamellae within 10 min. A deeper investigation of the particle formation kinetics revealed that internal structures of the particles were developed instantaneously during the early stage of solvent evaporation owing to the confinement effect and the fast-assembling BRCP architecture. Furthermore, the tunability of the domain spacings was demonstrated by examining the effect of the degree of polymerization of the side chains and backbones, which showed that the periodicity of the self-assembled morphology is determined by the length of the side-chains. In an attempt to expand the scope of particle structures via rapid self-assembly, particles with various morphologies such as concentric lamellae, coiled cylinders, and spheres-in-spheres were achieved by adjusting the volume fraction of BRCPs. Moreover, we prepared nanostructured Janus-like compartmentalized colloids with controlled shapes by blending homopolymer additives to facilitate macrophase separation of BRCP and homopolymers in addition to the microphase separation of BRCPs.

  • Minjoon Baek
  •  Hanseok Kim
  • Jaeman J. Shin