The Interfacial-Organized Monolayer Water Hindering the Aggregation of Nanographene: Both in Stacking and Sliding Assembly Pathways

TL;DR

This study uses computational methods to reveal that a monolayer of organized water at the interface prevents nanographene from aggregating, affecting both stacking and sliding assembly pathways.

Contribution

It is the first to demonstrate the hindering effect of interfacial-organized monolayer water on nanographene aggregation in multiple assembly pathways.

Findings

Interfacial water forms a compact, ordered monolayer with abundant hydrogen bonds.

No energy barrier was observed during the sliding assembly of graphene nanosheets.

The structure and hydrogen bonding of interfacial water are key to its hindering role.

Abstract

A computational investigation was carried out to understand the aggregation of nanoscale graphene with two typical assembly pathways of stacking assembly and sliding assembly in water. The interfacial-organized monolayer water film (MWF) hindering the aggregation of nanographene in both stacking and sliding assembly pathways was reported for the first time. By means of potential mean forces (PMFs) calculation, no energy barrier was observed during the sliding assembly of two graphene nanosheets, while the PMF profiles could be impacted by the contact forms of nanographene and the MWF within the interplate of two graphene nanosheets. To explore the potential physical basis of the hindering-role of self-organized interfacial water, the dynamical and structural properties as well as the status of hydrogen bonds (H-bonds) for interfacial water were investigated. We found that the compact, ordered structure and abundant H-bonds of the MWF could be taken as the fundamental aspects of the hindering-role of interfacial water for the hydrophobic assembly of nanographene. These findings are displaying a potential to further understand the hydrophobic assembly which mostly dominate the behaviors of nanomaterials, proteins etc. in aqueous solutions.