Non-spherical nanoparticles in block copolymer composites: nanosquares, nanorods and diamonds

TL;DR

This paper introduces a computational model to study the assembly of non-spherical nanoparticles with various shapes in block copolymer matrices, revealing how anisotropy influences their organization and interface behavior.

Contribution

It presents a novel hybrid modeling approach to analyze the assembly of anisotropic nanoparticles with complex shapes in BCPs, bridging simulations with experimental insights.

Findings

Square-like NPs form grid patterns within BCP domains.

Nanorods align along lamellar interfaces in BCPs.

Aspect ratio significantly affects nanoparticle aggregation and co-assembly.

Abstract

A hybrid block copolymer(BCP) nanocomposite computational model is proposed to study nanoparticles(NPs) with a generalised shape including squares, rectangles and rhombus. Simulations are used to study the role of anisotropy in the assembly of colloids within BCPs, ranging from NPs that are compatible with one phase, to neutral NPs. The ordering of square-like NPs into grid configurations within a minority BCP domain was investigated, as well as the alignment of nanorods in a lamellar-forming BCP, comparing the simulation results with experiments of mixtures of nanoplates and PS-\textit{b}-PMMA BCP. The assembly of rectangular NPs at the interface between domains resulted in alignment along the interface. The aspect ratio is found to play a key role on the aggregation of colloids at the interface, which leads to a distinct co-assembly behaviour for low and high aspect ratio NPs.