Novel nano-patterned structures of mixed hairy nanoparticles in single layer

Abstract

Tethering mixed homo/diblock polymer chains on the nanoparticles (NPs) imposes simultaneous enthalpic and entropic influences on their self-assembly. In the aggregation of these NPs, the chain distribution is strongly influenced by the neighboring NPs. Therefore, the so-called mutual templating of the NPs is the main reason for the formation of the exotic self-assembly structures of grafted chains. In this study, by using dissipative particle dynamics simulations, we design three representative mixed hairy nanoparticles (MHNPs) systems and investigate their microphase separation process during solvent evaporation. The minimal model for the MHNP is grafting two types of incompatible (A and B) homopolymer chains on the same graft-site with uniform distribution on the NP surface. Based on the minimal model, adding a C block at the free end of both A and B blocks facilitates the investigation of the influence of chain composition on microphase separation structures. In the third model, we change the B chain in the minimal model into a BC diblock copolymer chain to study the influence of chain mismatch on the formation of nano-patterns. By comparing the microphase structures and their formation processes, we can find that wedge-shaped nanostructures appear in specific range of interparticle distances (D) due to mutual templating; adding another block will terminate the mutual templating effect and results in the wedge-shaped nanostructures attaching to the NP surface surrounded by the ring structure formed by outer block C; for the systems with chain mismatch, apertures with six-fold symmetry appear in the monolayer film formed by MHNPs when D is large enough. These findings facilitate the design and fabrication of advanced functional materials with ordered structures on the nanoparticle level.