The role of the interface on surfactant transport to crude oil-water liquid-liquid interface

Liquid/liquid extraction (LLE) as one of the most industrially relevant separation methods, plays a key role in a wide variety of applications. The extraction process is carried out in the presence of extractant molecules, selectively transferring solutes from one phase to another, wherein surfactants are commonly used as extractants. However, the transport process of the class of surfactants itself draws very little attention, which will provide deep insights into understanding the dynamics and mechanisms of the extraction of surfactant-solute complexes. Herein, molecular dynamics simulations were used to investigate the dynamic process of surfactants adsorption on the oil-water interfaces at the molecular level. It was found that hydrophobic interaction drives the quick disintegration and diffusion of micelle-like surfactants upon contact with the oil-water interface. This work provides molecular-level insight into the transport mechanism of surfactants on oil-water interfaces.