Coalescence-induced wetting transition on nanoscale meshed surface: A molecular dynamic simulation study

Enclosed nanoscale meshed surfaces significantly enhance wetting transition and droplet detachment by confining the coalescence size of droplets. However, the water-repellency performance relies heavily on precise surface design. Here, molecular dynamic simulation is utilized to give a nanoscale insight into the mechanism of droplet detachment and the relationship between surface roughness and wetting transition, followed by a comparative analysis of two typical surfaces. Four coalescence modes are categorized based on droplet-to-mesh size ratios, with the dual-droplet confinement mode showing the best jumping performance due to efficient energy conversion. The influence of varying roughness parameters on the jumping ability of droplets in confined coalescence mode is analyzed to optimize surface design. Moreover, the weakened wetting transition capacity on the nanoscale meshed surface is driven by the formation of a low-velocity zone compared to that on the nanoscale pillared surface. The analysis of solid–liquid interaction energy and energy barriers highlights the hindering effect of meshed surfaces on the wetting transition. This study reveals the mechanism of coalescence-induced wetting transition and droplet detachment on nanoscale meshed surfaces by analyzing the distinct coalescence modes and comparing them with pillared surfaces, providing valuable insights for optimizing nanostructured surface design and enhancing heat transfer in industrial applications.