| 论文简介 |
Our molecular dynamics simulation demonstrates that the condensed nanodroplets can achieve self-jumping off the nanostructured surface driven by the Laplace pressure difference, which has not yet been experimentally observed. The growth and self-jumping dynamics of nanodroplets condensed on the super-hydrophilic nanostructured surface with local hydrophilic pinning site are systematically investigated. We reveal that a curvature difference between the droplet top and bottom is generated due to the confinement of the groove walls, which leads to a Laplace pressure difference. It increases with growing droplet and when it reaches the threshold against the pinning force from the hydrophilic pinning site, the droplet detaches from the groove valley and jumps off. We find that the characteristics of the hydrophilic pinning site shows competitive effects on the whole process, which can be generally divided into incubation and burst stages. Increasing the surface wettability and size of the pinning site drives the droplet to grow faster however makes the droplet departure harder in the meantime due to the increased pinning force. We also find that the droplet-jumping highly depends on the confined portion of the droplet after detaching from the pinning site and its decrease will diminish the excessive surface energy stored in the droplet, which makes the converted kinetic energy insufficient to drive the jump-off. Our work sheds light on the fundamental understandings of passive method for condensate removal, self-cleaning, thermal management, etc. |
(创新港)
