Effect of surface charge on wettability and electrolyte behavior on graphene surfaces using molecular dynamic simulation

Abstract

Abstract The interaction between electrolytes and graphene surfaces is critical in applications such as electro-wetting and energy storage. This study employs molecular dynamics simulations to investigate the influence of surface charge on electrolyte wettability and behavior. At 0.00 eV, the contact angle is 30.33°, indicating high wettability, while an increase in surface charge reduces wettability, with the contact angle rising to 36.88° at 0.06 eV and stabilizing at 62.30° at 0.15 eV. The lateral droplet spread decreases from 37.56 nm to 34.78 nm, indicating a more compact electrolyte distribution. Temperature simulations reveal a sharp rise exceeding 2000 K within picoseconds, peaking at 2800 K at 0.15 eV before stabilizing between 100 and 200 K. Potential energy increases from 0.081 $$\:\times\:$$ 107 kcal/mol to 3.520 $$\:\times\:$$ 107 kcal/mol, reflecting stronger electrostatic interactions. Additionally, the electric force rises with charge, consistent with Coulomb’s law, while the diffusion coefficient decreases from 8.0 Å2/ps to 6.0 Å2/ps, indicating reduced particle mobility. These findings enhance the understanding of surface charge effects on electrolyte behavior, contributing to the optimization of electro-wetting and energy storage applications.