Impact of graphene functionalization on CuO cluster behavior: insights from molecular dynamics

Abstract

This study explores how small clusters of copper oxide (CuO) interact with different graphene-based materials using molecular dynamics (MD) simulations. The research primarily aims to understand how graphene oxidation and the modification of the graphene surface with polyethylene glycol (PEG) chains influence the strength and dynamics of these interactions. Molecular models used include pristine graphene (PG), low-oxidized graphene oxide (GOL), high-oxidized graphene oxide (GOH), and PEGylated graphene oxide (GOH-PEG). Simulations reveal that cluster diffusion behavior varies with the surface characteristics of each graphene material. Specifically, clusters on PG surfaces exhibit higher mobility, whereas functionalized surfaces, especially PEGylated GO, significantly restrict cluster mobility due to stronger interactions. These findings correlate with calculated interaction energies, showing that increased cluster dynamics are associated with lower interaction energies. The analysis of the mean squared displacement (MSD) over time reinforces these conclusions, revealing that the cluster exhibits subdiffusive behavior, a hallmark of movement in environments that constrain particle displacement. This study offers valuable insights into the molecular mechanisms influencing metal nanocluster interactions and dynamic behavior on graphene-based materials, which is essential for advancing efficient new materials in biomedical applications.