Superhydrophobic Surfaces (SHSs) and Slippery Lubricant-Infused Porous Surfaces (SLIPSs) are proposed as excellent anti-icing, self-cleaning and condensation heat transfer surfaces due to their ability to repel water. The low droplet adhesion on SHSs and SLIPs is due to the low contact angle hysteresis displayed between the condensate and the surface, when compared to hydrophobic and/or to hydrophilic surfaces. In the case of SHSs, their extreme low adhesion is owed to the presence of air entrapped in between the condensate droplets and the surface, whereas in the case of SLIPS, their inherent low adhesion is due to the presence of a low surface energy lubricant oil in between the micro- and/or the nano-structures and the condensate. As a consequence, on both surfaces the condensate easily sheds by gravity and in the case of SHSs by coalescence-induced droplet-jumping. In this paper we investigate the condensation behavior on engineered SHSs and SLIPSs with structural roughness varying from the micro- to the nano-scale. Experimental observations and energy analysis is presented to demonstrate the different condensation performance observed depending on the surface structural finish underneath the condensate. We report the enhancement in the coalescence-induced droplet-jumping performance on SHSs and the greater theoretical heat transfer performance on SLIPSs. We conclude on the importance of taking into account the microstructures underneath the condensate for the optimum design of both SHSs and SLIPS.
|ジャーナル||International Heat Transfer Conference|
|出版ステータス||出版済み - 2018|
|イベント||16th International Heat Transfer Conference, IHTC 2018 - Beijing, 中国|
継続期間: 8 10 2018 → 8 15 2018
All Science Journal Classification (ASJC) codes