Spreading and splashing kinetics for impact of nanodroplets on lyophilic nanostructured surfaces

Abstract

The influence of nanostructure roughness on nanodroplets impact process is still unclear. In this Letter, we investigated the spreading and splashing kinetics of nanodroplets on lyophilic nanostructured surfaces by means of molecular dynamics simulation. The non-dimensional maximum spreading diameter (βmax) was favored with the increase of Weber number (We), and decreased with the increase in arithmetical mean roughness (Ra), furthermore, this relationship was no longer monotonically variable after We > 1000 since it was significantly influenced by the ejection of secondary droplets. With the increase of Ra, the transition of nanodroplets from spreading to splashing was suppressed, which attributed to the solid–liquid interface resistance inhibiting the advancing velocity of the whole lamella and evidenced by the slop in quasi-linear relationship between the critical value of (We/Oh)1/2 and Ra/D0. Our findings had important implications for which the control of nanodroplets deposition and surface self-cleaning.