Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, USA.
Phys Rev Lett. 2009 Oct 30;103(18):184501. doi: 10.1103/PhysRevLett.103.184501. Epub 2009 Oct 26.
In conventional dropwise condensation on a hydrophobic surface, the condensate drops must be removed by external forces for continuous operation. This Letter reports continuous dropwise condensation spontaneously occurring on a superhydrophobic surface without any external forces. The spontaneous drop removal results from the surface energy released upon drop coalescence, which leads to a surprising out-of-plane jumping motion of the coalesced drops at a speed as high as 1 m/s. The jumping follows an inertial-capillary scaling and gives rise to a micrometric average diameter at steady state.
在常规的疏水表面上的滴状冷凝中，必须通过外部力量去除冷凝液滴才能实现连续操作。本文报道了在超疏水表面上自发发生的连续滴状冷凝，而无需任何外部力量。自发的液滴去除源于液滴合并时释放的表面能，这导致合并后的液滴以高达 1 m/s 的速度产生出人意料的离面跳跃运动。跳跃遵循惯性-毛细缩放规律，并在稳定状态下产生出微米级的平均直径。
