Self-assembly of binary solutions to complex structures

TL;DR

This paper uses classical density functional theory to understand and control the self-assembly of binary soft matter systems, enabling the design of complex structures and concentration gradients.

Contribution

It introduces a method to tune intermolecular interactions based on intrinsic length scales to control self-assembly in binary mixtures.

Findings

Transition from miscible to aggregate structures achieved.

Guidelines for tuning interactions to form core-shell and mixed aggregates.

Control over concentration gradients within assemblies.

Abstract

Self-assembly in natural and synthetic molecular systems can create complex aggregates or materials whose properties and functionality rises from their internal structure and molecular arrangement. The key microscopic features that control such assemblies remain poorly understood, nevertheless. Using classical density functional theory we demonstrate how the intrinsic length scales and their interplay in terms of interspecies molecular interactions can be used to tune soft matter self-assembly. We apply our strategy to two different soft binary mixtures to create guidelines for tuning intermolecular interactions that lead to transitions from fully miscible, liquid-like uniform state to formation of simple and core-shell aggregates, and mixed aggregate structures. Furthermore, we demonstrate how the interspecies interactions and system composition can be used to control concentration gradients of component species within these assemblies. The insight generated by this work contributes towards understanding and controlling soft multi-component self-assembly systems. Additionally, our results aid in understanding complex biological assemblies and their function and provide tools to engineer molecular interactions in order to control polymeric and protein-based materials, pharmaceutical formulations, and nanoparticle assemblies.