Local Ordering Of Polymer-Tethered Nanospheres And Nanorods And The Stabilization Of The Double Gyroid Phase

TL;DR

This study uses Brownian dynamics simulations to explore how tethered nanospheres and nanorods self-assemble into the double gyroid phase, highlighting the role of local packing in stabilizing this complex structure.

Contribution

It demonstrates that local ordering of nanoparticles into specific packings is crucial for stabilizing the double gyroid phase in tethered nanoparticle systems.

Findings

Nanospheres form icosahedral-like clusters.

Nanorods form splayed hexagonal bundles.

Local order reduces packing frustration in the gyroid nodes.

Abstract

We present results of Brownian dynamics simulations of tethered nanospheres and tethered nanorods. Immiscibility between tether and nanoparticle facilitates microphase separation into the bicontinuous, double gyroid structure (first reported by Iacovella et al. [Phys. Rev. E 75 (2007)] and Horsch et al. [J. Chem. Phys. 125 (2006)] respectively). We demonstrate the ability of these nanoparticles to adopt distinct, minimal energy local packings, in which nanospheres form icosahedral-like clusters and nanorods form splayed hexagonal bundles. These local structures reduce packing frustration within the nodes of the double gyroid. We argue that the ability to locally order into stable structures is key to the formation of the double gyroid phase in these systems.