A Design Path for Hierarchical Self-Assembly of Patchy Colloids

TL;DR

This paper presents a hierarchical design approach enabling the self-assembly of patchy colloids into complex structures by controlling surface pattern formation through a predictive, minimalistic model, overcoming synthesis challenges.

Contribution

It introduces a novel design path for hierarchical self-assembly of patchy colloids using pattern universality and stoichiometry, allowing complex structures to form with limited control.

Findings

Successful self-assembly into various geometric structures

Patterns can be predicted and controlled with minimalistic models

Demonstrated versatility across different colloidal arrangements

Abstract

Patchy colloids are promising candidates for building blocks in directed self-assembly. To be successful the surface patterns need to both be simple enough to be synthesized, while feature-rich enough to cause the colloids to self-assemble into desired structures. Achieving this is a challenge for traditional synthesis methods. Recently it has been suggested that the surface pattern themselves can be made to self-assemble. In this paper we show that a wide range of functional structures can be made to self-assemble using this approach. More generally we present a design path for hierarchical targeted self-assembly of patchy colloids. At the level of the surface structure, we use a predictive method utilizing universality of patterns of stripes and spots, coupled with stoichiometric constraints, to cause highly specific and functional patterns to self-assemble on spherical surfaces. We use a minimalistic model of an alkanethiol on gold as a model system and demonstrate that, even with limited control over the interaction between surface constituents, we can obtain patterns that causes the colloids themselves to self-assemble into various complex geometric structures. We demonstrate how variations of the same design path cause in-silico self-assembly of strings, membranes, cubic and spherical aggregates, as well as various crystalline patterns.