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.