Enhanced oil droplet detachment from solid surfaces in charged nanoparticle suspensions

Abstract

The removal of oil droplets from solid surfaces is a key aspect in oil production and environmental protection. Recent progress shows that nanofluids exhibit distinct dynamic spreading behaviors compared with fluids without nanoparticles. Here, we investigated oil droplet detachment from solid surfaces immersed in charged nanoparticle suspensions via molecular dynamics simulations. Our simulated results demonstrate a significant enhancement of the oil removal efficiency using nanofluids of charged nanoparticles. When the charge on each particle exceeds a threshold value, the complete detachment of the oil droplet occurs spontaneously. Our results indicated that the surface wettability of the nanoparticles plays an essential role in oil removal processes. An increase in the interactions between nanoparticles and water molecules would obstruct the oil droplet detachment. The oil droplet detachment in the nanofluid flooding was also studied. Based on our findings, suspensions of charged hydrophobic nanoparticles can be considered to be high-performance agents in removing oil droplets from solid surfaces.