Transition of evaporation mechanisms in nanoscale liquid films: Effects of curvature and film thickness from molecular dynamics

Abstract

This study presents the first molecular dynamics investigation that systematically reveals the evaporation behavior of nanoscale liquid films on both planar and curved metallic substrates, addressing a critical gap in the understanding of phase change phenomena at non-planar interfaces. By constructing geometrically consistent systems with either flat or spherical gold substrates, and examining argon liquid films of varying thicknesses (2–9 nm), we comprehensively analyze the effects of surface curvature on interfacial heat transfer, evaporation front dynamics, and energy conversion efficiency. Simulation results demonstrate that the curved surface significantly enhances evaporation efficiency by reducing interfacial thermal resistance and intensifying molecular excitation, particularly under thinner film conditions. A semi-quantitative theoretical model is further proposed, establishing an inverse dependence of evaporation efficiency on both film thickness and substrate curvature radius, effectively capturing the efficiency trends observed in the simulations. This work not only deepens the fundamental understanding of evaporation dynamics on curved interfaces but also provides a new theoretical and methodological basis for thermal management design in micro/nanoscale systems, offering substantial scientific and engineering value.