Modeling Direct Exfoliation of Nanoscale Graphene Platelets

Direct ultrasonication of graphite particles dispersed in water, in the presence of a surfactant, is a promising way to produce pristine nanoscale graphene platelets (NGPs) without graphite intercalation or oxidation. We investigate possible exfoliation mechanisms, specifically those involving sodium dodecylbenzenesulfonate (SDBS) surfactant, and compare their corresponding energies. The model includes interlayer van der Waals interactions and a force-field approach capable of treating charged surfactant and solvent. Our calculations reveal the significant role of SDBS in liquid-phase NGP production, through a locking mechanism that prevents restacking.