Enhanced condensation on a biphilic-zigzag surface due to self-arrangement of crystals on a micro-structured surface. (November 2021)

• Record Type: Journal Article
• Authors: Han, Taeyang; Choi, Younghyun; Na, Kyung Mi; Kim, Moo Hwan; Jo, HangJin
• Is Part Of: International journal of heat and mass transfer. Volume 179(2021)
• Publication Date: 2021-11
• Subjects: Self-arrangement -- Condensation -- Droplet-jumping -- Heterogeneous wettability -- Heat transfer; Heat -- Transmission -- Periodicals; Mass transfer -- Periodicals; Chaleur -- Transmission -- Périodiques; Transfert de masse -- Périodiques; Electronic journals; 621.4022
• DOI: 10.1016/j.ijheatmasstransfer.2021.121710
• Languages: English
• ISSNs: 0017-9310

Abstract

Highlights: The crystal self-arrangement is demonstrated using a capillary flow Condensation enhances by combining hierarchical structures and biphilic wettability The developed surface increases the droplet jumping frequency by up to 1385% The way to enhance the efficiency of jumping-mode condensation is demonstrated Abstract: Applying micro-nano hierarchical structures or hydrophilic patterns on superhydrophobic surfaces has showed the potential to increase the condensation efficiency by promoting the coalescence-induced jumping. In this study, the crystal self-arrangement is demonstrated using a capillary flow to combine the advantages of the hierarchical structures and the biphilic wettability for the further enhancement of the condensation efficiency. Such flow transports the crystals to the inner tips of the V-shapes during the evaporation of an ethanol-water film on the zigzag structured surface. These crystals induce the condensations inside the V-shapes that guide the condensed droplets to the gap between the zigzag structures, which promotes the coalescence between the condensed droplets. Consequently, the developed surface increases the jumping frequency by up to 1385%, and the cumulative volume of the jumping droplets and the heat transfer coefficient on the developed surface are approximately 2.2 and 2.7 times higher than that of the state-of-the-art superhydrophobic surface. Our findings pave the way for enhancing the efficiency of the jumping-mode condensation for diverse applications by providing a scalable method, which maximizes the profits that the hierarchical structures and the biphilic wettability give. Graphical abstract: Image, graphical abstract