Understanding self-assembly mechanisms in supramolecular fiber materials through multiscale simulation

Abstract

Supramolecular materials, assembled through non-covalent interactions, have emerged as a versatile and tunable platform for the development of advanced functional materials with tailored properties and applications. However, comprehending the interactions between self-assembled monomers at the molecular level, particularly when organized into fibrous structures, remains a considerable challenge. In this study, we discovered that solely relying on all-atomistic molecular dynamics simulations is insufficient to reproduce the self-assembly process and the formation of fibrous supramolecular structures. Thus, we combined dissipative particle dynamics (DPD) and all-atomistic molecular dynamic simulations to accurately simulate the fibrous supramolecular structures previously observed in experiments. These structures consist of benzene-1,3,5-tricarboxamide (BTA-EG4), 2-ureido-4 [1H]-pyrimidinone-ethylene glycol molecules (UPy-EG), and glycyrrhizic acid (GA) molecules, each exhibiting varying degrees of topology and planarity. Our analyses focused on elucidating the stability mechanism of these fibrous structures. Notably, we found that hydrogen bonds, π-π interactions and nonbonded interactions, especially Coulomb interaction between monomers and water molecules, play pivotal roles in stabilizing these fibrous structures. This study significantly contributes to our understanding of self-assembly mechanism in supramolecular fiber materials and opens avenues for extending this knowledge to other fibrous supramolecular architectures.