Entropy-Driven Hierarchical Nanostructures from Cooperative Self-Assembly of Gold Nanoparticles/Block Copolymers under Three-Dimensional Confinement

Abstract

The cooperative self-assembly of polystyrene-b-poly(4-vinylpyridine) block copolymers (BCPs) and gold nanoparticles (AuNPs) confined within the emulsion droplets is studied by combining both the experiments and Monte Carlo simulations. The results indicate that the entropic interaction between the AuNPs and BCP domain is a critical parameter to dominate the spatial arrangement of AuNPs and the nanostructure of the hybrid nanoparticles, which can be utilized to design novel hierarchical hybrid nanoparticles. Based on this theoretical observation, a large number of unique Janus hybrid nanoparticles, including pupa-like nanoparticles with AuNPs concentrated at one pole of the particles, spherical nanoparticles with AuNPs enriched in a bulge on the sphere surface, and the gourd-like, clover-like, and four-leaf-clover-like nanoparticles from the further hierarchical assembly of small hybrid Janus nanoparticles, are fabricated via three-dimensional (3D) confined self-assembly.