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Spatial Control of Heterogeneous Nucleation on the Superhydrophobic Nanowire Array
Author(s) -
Lo ChingWen,
Wang ChiChuan,
Lu MingChang
Publication year - 2014
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201301984
Subject(s) - nucleation , materials science , nanowire , condensation , drop (telecommunication) , nanotechnology , surface energy , surface roughness , microscale chemistry , chemical physics , heat transfer , thermodynamics , composite material , telecommunications , physics , mathematics education , mathematics , computer science
Condensation is a common phenomenon and is widely exploited in power generation and refrigeration devices. Although drop‐wise condensation offers high heat and mass transfer rates, it is extremely difficult to maintain and control. In this study, the ability to spatially control heterogeneous nucleation on a superhydrophobic surface by manipulating the free energy barrier to nucleation through parameterizing regional roughness scale on the Si nanowire array‐coated surface is reported. Water vapor preferentially condenses on the designed microgrooves on the Si nanowire surface and continuous shedding of the drop‐wise condensate is observed on the surface. The nucleation site density can also be manipulated by tailoring the density of the microgroove on the surface. Moreover, the cycle time on the Si nanowire array with microgrooves is approximately ten times smaller than that on a plain Si surface. This suggests that potentially high heat and mass transfer rates can be achieved on the surface. The insight from this study has implications in enhancing energy efficiency in a wide range of thermal energy conversion systems.