Dropwise Condensation on Superhydrophobic Surfaces
Overview
Ching-Wen Lo 羅景文 & Chien-Chang Lin 林建璋
Vapor condensation includes droplet nucleation, growth, coalescence and departure. Nucleation plays an important role in the condensation process. In general, heterogeneous nucleation of liquid droplets on a solid surface is randomly distributed.The silicon nanowire array consists of a large number of nanowires with wire diameter and spacing of approximately 200 nm. Nucleation density on the silicon nanowire array is greatly been improved.
Vapor condensation includes droplet nucleation, growth, coalescence and departure. Nucleation plays an important role in the condensation process. In general, heterogeneous nucleation of liquid droplets on a solid surface is randomly distributed.The silicon nanowire array consists of a large number of nanowires with wire diameter and spacing of approximately 200 nm. Nucleation density on the silicon nanowire array is greatly been improved.
Current work
We are the first study demonstrating the ability to control heterogeneous nucleation on a superhydrophobic surface. The surface having the silicon nanowire array with microgrooves is a two-tier roughened surface. The surface can not only increase nucleation density but also control the positions of the nuclei on the surface. The spatial control of heterogeneous nucleation is achieved by manipulating free energy barriers on the two-tier roughened surface. In addition, continuous shedding of the drop-wise condensate is observed on the two-tier roughened surface. As a result, the mass transport rate on the surface is enhanced. The two-tier roughed surface has implications in enhancing efficiencies in heat engines, water harvesting and desalination systems.
SEM images for the surface having the silicon nanowire array with microgrooves is a two-tier roughened
Visualization of Dropwise Condensation Under ESEM
The Underlying Mechanism for the Spatial Control of Nucleation
Video Gallery
Functionalized Surface (PlainSi)
Nano structured surface (SiNWs)
Nucleation Mechanism (P85)
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Micro-Nano structured surface (P85)
Micro-Nano structured surface (P45)
Micro-Nano structured surface (P25)
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