Directed self-assembly of Janus nanorods in binary polymer mixture: towards precise control of nanorod orientation relative to interface

Abstract

The ability to control the organization of anisotropic nanoparticles, such as nanorods, with high precision would greatly facilitate the fabrication of functional materials. Using a hybrid computational model, we systematically investigate the directed self-assembly of Janus nanorods, with two chemically different surface compartments, in binary polymer mixtures. Our simulations demonstrate that the energetic contributions from the surface chemistry of the Janus nanorods, the rod-rod interaction, and the spatial confinement from the polymer phases can be tailored to tune the orientation angle of the nanorods with respect to phase interface, leading to the formation of ''lying'', tilt, and ''standing'' interfacial superstructures. A detailed insight into the mechanism regarding this precise control of nanorod orientation at the interface is obtained by evaluating the rod-phase interaction energy and the entropic energy of the tethered ligands on the rods. Furthermore, since the Janus rods are localized at the interface between two polymer phases, the structural evolution of the polymer nanocomposites is dramatically curtailed. This kinetic arrest is found to depend on the surface chemistry and the aspect ratio of Janus rods. The results demonstrated in this paper offer a novel approach to achieve morphological and kinetic control in nanoscopic composites towards unique photovoltaic and mechanical properties.

Block copolymer–nanoparticle composites: Structure, functional properties, and processing

“…Nanoparticles with Janus surface properties, e.g., due to grafting of two different types of polymeric ligands on the same NP, can have favorable interactions with both the blocks of a given BCP, and thus can localize in the interfacial regions where different blocks are joined [93][94][95][96][97][98]. For example, grafting both PS and P2VP ligands on gold NPs resulted in NP location in the interfacial regions of PS-P2VP BCPs [70].…”

Dissipative particle dynamics studies on the interfacial tension of A/B homopolymer blends and the effect of Janus nanorods

“…As a conventional coil compatibilizer, amphiphilic surfactants and block copolymers [Figure (a,b)] were often added to the blends to achieve this aim . Recently, rigid nanoparticles have often been utilized to control the polymer structures as a strategy for tailoring the properties of the material, since the rigid nanoparticles can self‐assemble at the interface of the two phases and influence the interfacial properties. For example, Luo and coworkers investigated the effect of the nanoparticles on the water/trichloroethylene interface.…”

“…showed that the decane/water interfacial tension is not much influenced by the silica nanoparticles with different surface chemistry. Yan and coworkers testified that the nanorod can decrease the interfacial tension. However, they did not provide the measurable relationships.…”

Self-assembly of rod-coil-rod triblock copolymers: A route toward hierarchical liquid crystalline structures

“…[25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40] They could provide more straightforward results than pure experiments and overcome the limitation inherent in experiments. So far, various approaches, such as self-consistent field theory (SCFT), [25][26][27][28] Brownian dynamics (BD) simulations, [29][30][31] and dissipative particle dynamics (DPD) simulations, 32,33 were successfully applied to investigate the phase behavior of the block copolymers with rod blocks.…”