Influence of liquid–solid intermolecular force on levitation of impacting nanodroplet

When droplets impact on a heated wall, they can levitate owing to the vapor stream generated by the droplet evaporation. This phenomenon is called the Leidenfrost effect, and the vapor layer prevents heat transfer between the droplet and heated wall. In this study, we investigated the influence of the intermolecular force between liquid and solid molecules on the levitating phenomenon, which is caused by heat transfer, for nanodroplets. We used a molecular dynamics (MD) simulation to evaluate the detailed behavior of droplet levitation and investigated the temperature field of the impacting droplet. We found that the droplet levitation was likely to occur at lower temperature when the intermolecular force was stronger. In addition, when the intermolecular force was strong enough, the liquid molecules stayed on the heated wall and an adsorption layer was formed. This adsorption layer exceeded the critical temperature of the liquid molecules, and the existence of the adsorption layer significantly affected the onset of the droplet levitation.