Hierarchical self-assembly of anisotropic colloidal platelets

TL;DR

This paper investigates how anisotropic colloidal platelets with specific interaction sites self-assemble into complex structures, revealing how tuning interaction parameters guides the formation of stable, ordered materials.

Contribution

It introduces a model of rhombic colloidal platelets with controllable interaction sites and explores their two-stage self-assembly process via Monte Carlo simulations.

Findings

Successful formation of micellar aggregates with defined symmetries

Controlled transition from clusters to stable hexagonal lattices

Tuning interaction parameters directs assembly pathways

Abstract

Anisotropy at the level of the inter-particle interaction provides the particles with specific instructions for the self-assembly of target structures. The ability to synthesize non-spherical colloids, together with the possibility of controlling the particle bonding pattern via suitably placed interaction sites, is nowadays enlarging the playfield for materials design. We consider a model of anisotropic colloidal platelets with regular rhombic shape and two attractive sites placed along adjacent edges and we run Monte Carlo simulations in two-dimensions to investigate the two-stage assembly of these units into clusters with well-defined symmetries and, subsequently, into extended lattices. Our focus is on how the site positioning and site-site attraction strength can be tuned to obtain micellar aggregates that are robust enough to successively undergo to a second-stage assembly from sparse clusters into a stable hexagonal lattice.