Molecular Dynamics Simulations of Liquid-Liquid Interfacial Properties between Water and Hydrophobic Deep Eutectic Solvents

Deep eutectic solvents (DES) emerged recently as candidates for extracting organic molecules from aqueous solutions. The liquid-liquid interfaces between aqueous solutions and DES play a determining role in the ability of DES to extract organic molecules. A better understanding of the DES/aqueous liquid-liquid interfaces can help develop an efficient and cost-effective extraction process. We investigate the structural and dynamic properties of molecules at the liquid-liquid interfaces in several hydrophobic DES/water systems using molecular dynamics simulations. The analysed properties include density distribution and diffusion of DES composition and water molecules, and hydrogen bonding between DES compositions and water molecules at the interface. The simulation results enable us to develop a fundamental relationship between DES compositions and the properties of the DES-a­­­queous interface. This relationship can help us to develop DES that can form a desired interface with the aqueous solution.