Lubricant-enhanced self-transport of condensed nanodroplets trapped in Wenzel state

Condensates are extremely easy to be trapped in micro/nano-gaps of surfaces and stay in the sticky Wenzel wetting state due to the nucleation. Rather than avoiding the unexpected Wenzel state, an efficient detachment of Wenzel condensates is targeted in present work. A bionic lubricant-impregnated wedge-groove surface is proposed inspired by a combination of the conical cactus spines and the oil-immersion structure of pitcher plants. The dynamic behaviours of a single nanodroplet and condensates are investigated using molecular dynamics simulations. By taking advantage of the conical structure and the thoroughly wetted liquid–solid interface in the groove, droplets trapped in the Wenzel state are observed to move spontaneously on the proposed patterned surface, while droplets in the Cassie state are found immobile. Moreover, the nucleation sites can be controlled and the nucleation energy barriers are also reduced by the proposed surface. The present work can pave a new path to manipulate the droplets in the sticky Wenzel state with higher nucleation and drainage rate, which is desired to provide an energy-efficient method for efficient condensation.