کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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4981604 | 1453836 | 2018 | 10 صفحه PDF | دانلود رایگان |
After a hydrophilic surface is partially coated with a superhydrophobic material, the resulting chemically patterned surface has a strong ability to split droplets. For example, a 2.54-mm-diameter water droplet impinging on a chemically striped surface at 0.58Â m/s can split off a satellite droplet. In this article, the droplet splitting behavior is investigated by the coupled level set/volume-of-fluid method. It is found that as the impact velocity increases, the number of satellite droplets tends to rise. When the impact velocity reaches 1.69Â m/s, a large number of satellite droplets are produced, increasing the length of the triple-phase contact line. Compared with that on an uncoated hydrophilic surface, the triple-phase contact line length of a droplet impinging on the chemically striped surface improves by 81.93% at the same impact velocity, and the longer triple-phase contact line can greatly enhance droplet evaporation on a hot surface. Furthermore, the impact position of the droplet significantly affects the length of the triple-phase contact line. When the droplet strikes a hydrophilic stripe, the triple-phase contact line length can be greatly enlarged (by 169.66%). Moreover, the mechanism of droplet splitting can be explained as follows: a pressure difference caused by the hysteretic movement of the liquid on the superhydrophobic stripes forces the liquid to move away from the superhydrophobic area to the hydrophilic area.
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Journal: Colloids and Surfaces A: Physicochemical and Engineering Aspects - Volume 537, 20 January 2018, Pages 139-148