Effect of electric field intensity on electrophoretic migration and deformation of oil droplets in O/W emulsion under DC electric field: A molecular dynamics study

• Oil phase molecules are attracted to each other mainly by Van der Waals forces. • The mechanism of droplet migration and deformation is explained by weak interaction. • Negative electrophoretic migration occurred in the oil droplets. • The negative charge of the droplet is aligned towards the anode. • The presence of NaCl hinders the migration of oil droplets under the electric field. Removing oil droplets from O/W emulsion is a difficult problem at present. In order to explore the effect of electric field intensity on the migration and deformation of oil droplets in O/W emulsion, in this paper, the motion behavior of oil droplets under DC electric field is studied based on molecular dynamics simulation. It is found that oil phase molecules are attracted together by Van der Waals interaction. When E = 0.7 V/nm, the deformation degree reaches the maximum 0.534, and the overall migration speed of the oil droplet is 0.03266 nm/ps. Negative electrophoretic migration of oil droplets occurs under electric field, which is similar to the experimental results. The effect of electric field intensity on oil droplet migration and deformation is explored for the first time, and the relevant results can provide theoretical guidance for improving the purification process of oily wastewater.