Condensation on superhydrophobic copper oxide nanostructures

Ryan Enright, Nicholas Dou, Nenad Miljkovic, Youngsuk Nam, Evelyn N. Wang

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Condensation is an important process in both emerging and traditional power generation and water desalination technologies. Superhydrophobic nanostructures promise enhanced condensation heat transfer by reducing the characteristic size of departing droplets via a surface-tension-driven mechanism [1]. In this work, we investigated a scalable synthesis technique to produce oxide nanostructures on copper surfaces capable of sustaining superhydrophobic condensation and characterized the growth and departure behavior of condensed droplets. Nanostructured copper oxide (CuO) films were formed via chemical oxidation in an alkaline solution. A dense array of sharp CuO nanostructures with characteristic heights and widths of ∼1 μm and ∼300 nm, respectively, were formed. A gold film was deposited on the surface and functionalized with a self-assembled monolayer to make the surfaces hydrophobic. Condensation on these surfaces was then characterized using optical microscopy (OM) and environmental scanning electron microscopy (ESEM) to quantify the distribution of nucleation sites and elucidate the growth behavior of individual droplets with a characteristic size of ∼1 to 10 μm at low supersaturations. Comparison of the observed behavior to a recently developed model for condensation on superhydrophobic surfaces [2, 3] suggests a restricted regime of heat transfer enhancement compared to a corresponding smooth hydrophobic surface due to the large apparent contact angles demonstrated by the CuO surface.

Original languageEnglish (US)
Title of host publicationASME 2012 3rd International Conference on Micro/Nanoscale Heat and Mass Transfer, MNHMT 2012
Pages419-425
Number of pages7
DOIs
StatePublished - Dec 1 2012
Externally publishedYes
EventASME 2012 3rd International Conference on Micro/Nanoscale Heat and Mass Transfer, MNHMT 2012 - Atlanta, GA, United States
Duration: Mar 3 2012Mar 6 2012

Publication series

NameASME 2012 3rd International Conference on Micro/Nanoscale Heat and Mass Transfer, MNHMT 2012

Other

OtherASME 2012 3rd International Conference on Micro/Nanoscale Heat and Mass Transfer, MNHMT 2012
CountryUnited States
CityAtlanta, GA
Period3/3/123/6/12

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ASJC Scopus subject areas

  • Fluid Flow and Transfer Processes

Cite this

Enright, R., Dou, N., Miljkovic, N., Nam, Y., & Wang, E. N. (2012). Condensation on superhydrophobic copper oxide nanostructures. In ASME 2012 3rd International Conference on Micro/Nanoscale Heat and Mass Transfer, MNHMT 2012 (pp. 419-425). (ASME 2012 3rd International Conference on Micro/Nanoscale Heat and Mass Transfer, MNHMT 2012). https://doi.org/10.1115/MNHMT2012-75277