Slippery Wenzel State

Xianming Dai, Birgitt Boschitsch Stogin, Shikuan Yang, Tak Sing Wong

Research output: Contribution to journalArticle

92 Scopus citations

Abstract

Enhancing the mobility of liquid droplets on rough surfaces is of great interest in industry, with applications ranging from condensation heat transfer to water harvesting to the prevention of icing and frosting. The mobility of a liquid droplet on a rough solid surface has long been associated with its wetting state. When liquid drops are sitting on the top of the solid textures and air is trapped underneath, they are in the Cassie state. When the drops impregnate the solid textures, they are in the Wenzel state. While the Cassie state has long been associated with high droplet mobility and the Wenzel state with droplet pinning, our work challenges this existing convention by showing that both Cassie and Wenzel state droplets can be highly mobile on nanotexture-enabled slippery rough surfaces. Our surfaces were developed by engineering hierachical nano- and microscale textures and infusing liquid lubricant into the nanotextures alone to create a highly slippery rough surface. We have shown that droplet mobility can be maintained even after the Cassie-to-Wenzel transition. Moreover, the discovery of the slippery Wenzel state allows us to assess the fundamental limits of the classical and recent Wenzel models at the highest experimental precision to date, which could not be achieved by any other conventional rough surface. Our results show that the classical Wenzel eq (1936) cannot predict the wetting behaviors of highly wetting liquids in the Wenzel state.

Original languageEnglish (US)
Pages (from-to)9260-9267
Number of pages8
JournalACS nano
Volume9
Issue number9
DOIs
StatePublished - Sep 22 2015

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Engineering(all)
  • Physics and Astronomy(all)

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    Dai, X., Stogin, B. B., Yang, S., & Wong, T. S. (2015). Slippery Wenzel State. ACS nano, 9(9), 9260-9267. https://doi.org/10.1021/acsnano.5b04151