Anomalous Impact of Surface Wettability on Leidenfrost Effect at Nanoscale

Leidenfrost effect is a common and important phenomenon which has many applications, however there is a limited body of knowledge about the Leidenfrost effect at the nanoscale regime. We investigate the impact of substrate wettability on Leidenfrost point temperature (LPT) of nanoscale water film via molecular dynamics simulations, and reveal a new mechanism different from that at the macroscale. In the molecular dynamics simulations, a method of monitoring density change at different heating rates is proposed to obtain accurate LPT under different surface wettability. The results show that LPT decreases firstly and then increases with the surface wettability at the nanoscale, which is different from the monotonous increasing trend at the macroscale. The mechanism is elucidated by analyzing the competitive effect of adhesion force and interfacial thermal resistance, as well as different contributions of gravity on LPT at the nanoscale and macroscale. The investigations can deepen the understanding of Leidenfrost effect at the nanoscale regime and also facilitate to guide the applications of heat transfer and flow transport.

Automated summary

This research investigates the impact of substrate wettability on the Leidenfrost point temperature of nanoscale water film through molecular dynamics simulations, revealing a new mechanism different from that at the macroscale. The results show that the Leidenfrost point temperature initially decreases and then increases with surface wettability at the nanoscale, which is different from the monotonous increasing trend at the macroscale. The mechanism is elucidated by analyzing the competitive effect of adhesion force, interfacial thermal resistance, and gravity on the Leidenfrost point temperature at different scales.