Explosive boiling of suspended argon films in the cassie-baxter state on nanopillar-arrayed surfaces

Abstract

The explosive boiling of a Cassie-Baxter (CB) state argon film suspended on nanopillar-arrayed surfaces is for the first time systematically investigated via molecular dynamics (MD) simulations. As the CB state liquid films with various thicknesses explode on nanopillar-arrayed surfaces, owing to the delayed local accumulation of energy on the thicker liquid film, the onset time of explosive boiling is increased with increased thickness of suspended liquid film, resulting from increased hydraulic diameter. Although the hydraulic diameter is decreased with increased nanopillar height, the onset time remains unchanged for a suspended liquid film over a nanopillar-arrayed surface with varying nanopillar heights. The invariant onset time with decreased hydraulic diameter is attributable to the incapability of liquid argon atoms to infiltrate into nanogrooves between nanopillars, producing a constant area for heat transfer between liquid films and solid surfaces, even the nanopillar height is increased. The surface potential energy has been significantly increased with increased inherent wettability of surfaces, leading to a stronger interaction between liquid and solid atoms. Thus, more argon atoms adsorb heat to rapidly trigger the separation of suspended liquid films from the nanopillar-arrayed surface. With enhanced surface wettability, the onset time would be decreased with decreased intrinsic contact angle of the nanopillar-arrayed surface.