Preparation of Graphene and Its Tribological Properties Based on Deep Eutectic Solvent Stripping Method

Graphene (GP), when used as a lubricant additive, not only reduces the friction coefficient but also enhances wear resistance by forming a protective lubrication film. However, there are still several challenges in practical applications related to graphene preparation. Therefore, this study employs a novel type of ionic liquid deep eutectic solvent as an interlayer agent for graphene preparation and investigates its tribological properties when used as an additive. We used choline chloride/ethylene glycol deep eutectic solvent as the intercalation agent and successfully prepared graphene samples using liquid-phase exfoliation. The resulting graphene samples had a thickness of 4–5 layers. The peeling mechanism is analyzed through molecular dynamics simulations and characterization techniques such as Raman spectroscopy, XRD, SEM, and AFM. In friction experiments conducted with different mass fractions of 1.5 wt% DES and 0.05 wt% GP as lubricant additives, it is observed that the mixture exhibits optimal lubrication performance compared to base oil alone; specifically reducing average friction coefficient by 56.8% and depth of wear marks by 59.8%. This enhancement in friction performance can be attributed to both high wettability and synergistic effects between composite lubricants. Considering the wide range of available DESs and two-dimensional materials, these newly developed functional two-dimensional materials based on DES hold significant research potential.