Deep Eutectic Solvent Interaction with Graphene Oxide: A Combined Experimental and Molecular Dynamics Characterization

The interaction between graphene oxide (GO) and deep eutectic solvents (DESs) plays a crucial role in the design of functional materials for a wide range of applications. In this study, we present a combined experimental and computational investigation aimed at elucidating the structural and molecular organization of GO–DES systems using ethaline and reline as model deep eutectic solvents. These two DESs are among the most widely studied and well-characterized, making them ideal benchmarks for probing GO–liquid interactions. We synthesized GO and performed a detailed characterization via X-ray photoelectron spectroscopy (XPS), obtaining precise information about the type and distribution of oxygen-containing functional groups. Based on these experimental data, we developed a realistic molecular model of GO, providing a reliable and reproducible framework for atomistic simulations. Infrared and Raman spectroscopies reveal specific changes in vibrational modes upon GO–DES interaction, while differential scanning calorimetry (DSC) indicates modifications in thermal behavior. Classical molecular dynamics (MD) simulations show the formation of hydrogen-bond networks between the DES components and GO surface functionalities. Our results demonstrate a reciprocal structural influence between GO and DES at the molecular level and establish a validated computational protocol for the study of these hybrid systems.