Dynamics of droplets on a thin [EMIm]Ac ionic liquid film

The impact of water and 1-ethyl-3-methylimidazolium acetate ([EMIm]Ac) drops on [EMIm]Ac ionic liquid film was studied. The hydrodynamics of the impact of drops on a water liquid film were compared. A higher Weber number contribute to a larger crown rim diameter and height. The variation trend of the crown rim diameter and height with the liquid film thickness differs much according to the drop and film properties. The crown rim diameter and height have an opposite variation trend with the increasing liquid film temperature. The crown rim diameters with different droplet and liquid film properties were almost the same at the early stage of impact of approximately 4 ms, and then the difference became larger at a later stage. The shape of the generated liquid crown was more regular for drops impact on ionic liquid film. The water droplet impact on a water film has the largest liquid crown rim diameter and height, while the ionic liquid droplet impact on the ionic liquid film has the lowest.