Self-pumping ultra-thin film evaporation on CNT-embedded silicon nitride nanopore membrane

The development of nanoporous membrane structure provides a potential opportunity for the advanced ultra-thin liquid film evaporation process, for which the ability of effectively and continuously maintaining the nano-thin liquid film is crucial to realize its superior performance. In this work, we elucidated the nanopore-based ultra-thin water film evaporation characteristics with non-equilibrium molecular dynamics simulation. A self-pumping water transport through the nanopore was observed, which is attributed to the driving force induced by the evaporation meniscus of thin liquid film. The dry-out crisis will occur with the increasing membrane thickness. We demonstrated that the hydrophobic carbon nanotube (CNT) can be utilized as the coating inside the hydrophilic silicon nitride (Si₃N₄) nanopore, which reduces the flow resistance and presents an excellent capability to replenish the evaporated water. Based on the above findings, the internal coating of CNT is an advisable strategy for nanopore-based ultra-thin liquid film evaporation, possessing a stable high evaporation flux as well as a good mechanical strength.