Effect of Microstructures on Superhydrophobic and Slippery Lubricant-Infused Porous Surfaces During Condensation Phase-Change
Effect of Microstructures on Superhydrophobic and Slippery Lubricant-Infused Porous Surfaces During Condensation Phase-Change
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凝聚相变过程中微结构对超疏水和光滑注入润滑剂的多孔表面的影响
DOI：
10.1115/icnmm2018-7640
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
Takata Yasuyuki
中科院分区：
文献类型：
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作者：
Orejon Daniel;Maeda Yota;Lv Fengyong;Zhang Peng;Takata Yasuyuki
超疏水表面（SHS）和光滑多孔表面（SLIPS）因其优异的防冰、防雾、自清洁和冷凝传热性能而受到越来越多的关注。这种表面被动地脱落和排斥水的能力主要是由于液体和固体表面之间的低粘附性，即，与亲水或疏水表面相比，接触角滞后低。在这项工作中，我们研究了表面结构对SHS和SLIPS冷凝性能的影响。三种不同的SHS的结构不同，从微米到纳米尺度的制作简单和可扩展的蚀刻和氧化生长过程。在温度和湿度受控的环境室中通过光学显微镜评估在这样的表面上的冷凝性能。在SHS的重要差异的大小和数量的聚结液滴所需的跳跃，以确保被发现时，不同的冷凝液滴下面的表面结构。提出了一种表面能分析来解释微结构对液滴跳跃性能的抑制。另一方面，通过用低表面张力油浸渍相同的SHS，SLIPS，可以进一步减少冷凝物和SLIPS之间的粘附。在SLIPS上，观察到液滴密度随时间变化的轻微差异以及包含微结构后的脱落性能。液滴脱落速度更快，更小的直径SLIPSs的存在下的微结构相比，单独的纳米结构SLIPSs.We得出结论，在SHS的液滴跳跃性能的微米液滴恶化的微结构的存在下，随之而来的传热性能下降，而SLIPSs的液滴的自去除实际上是在微结构的存在下得到改善。
Superhydrophobic surfaces (SHSs) and slippery lubricant-infused porous surfaces (SLIPSs) are receiving increasing attention for their excellent anti-icing, anti-fogging, self-cleaning and condensation heat transfer properties. The ability of such surfaces to passively shed and repel water is mainly due to the low-adhesion between the liquid and the solid surface,i.e., low contact angle hysteresis, when compared to hydrophilic or to hydrophobic surfaces. In this work we investigated the effect of surface structure on the condensation performance on SHSs and SLIPSs. Three different SHSs with structures varying from the micro- to the nano-scale were fabricated following easy and scalable etching and oxidation growth procedures. The condensation performance on such surfaces was evaluated by optical microscopy in a temperature and humidity controlled environmental chamber. On SHSs important differences on the size and on the number of the coalescing droplets required for the jump to ensue were found when varying the surface structure underneath the condensing droplets. A surface energy analysis is proposed to account for the suppression of the droplet-jumping performance in the presence of microstructures. On other hand, by impregnating the same SHSs with a low surface tension oil,i.e., SLIPSs, the adhesion between the condensate and the SLIPSs can be further reduced. On SLIPSs slight differences on the droplet density over time and shedding performance upon the inclusion of microstructures were observed. Droplets were found to shed faster and with smaller diameters on SLIPSs in the presence of microstructures when compared to solely nanostructured SLIPSs.We conclude that on SHSs the droplet-jumping performance of micrometer droplets is deteriorated in the presence of microstructures with the consequent decrease in the heat transfer performance, whereas on SLIPSs the droplet self-removal is actually improved in the presence of microstructures.