Topography-Directed Hot-Water Super-Repellent Surfaces

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

13 Scopus Citations
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Author(s)

Detail(s)

Original languageEnglish
Article number1900798
Journal / PublicationAdvanced Science
Volume6
Issue number18
Online published30 Jul 2019
Publication statusPublished - 18 Sep 2019
Externally publishedYes

Link(s)

Abstract

Natural and artificial super-repellent surfaces are frequently textured with pillar-based discrete structures rather than hole-based continuous ones because the former exhibits lower adhesion from the reduced length of the three-phase contact line. Counterintuitively, here, the unusual topographic effects are discovered on hot-water super-repellency where the continuous microcavity surface outperforms the discrete microneedle/micropillar surface. This anomaly arises from the different dependencies of liquid-repellency stability on the surface structure and water temperature in the two topographies. The unexpected wetting dynamics are interpreted by determining timescales for droplet evaporation, vapor condensation, and droplet bouncing. The associated heat transfer process is unique to the wetting states and remarkably distinct from each other in the two topographies. It is envisioned that hot-water super-repellent microcavity surfaces will be advantageous for a variety of applications, especially when both self-cleaning and thermal insulation are imperative, such as clothing for scald protection and digital microfluidics for exothermic reactions.

Research Area(s)

  • heat transfer, liquid repellency, structure–property relationship, wetting dynamics

Citation Format(s)

Topography-Directed Hot-Water Super-Repellent Surfaces. / Zhu, Pingan; Chen, Rifei; Wang, Liqiu.

In: Advanced Science, Vol. 6, No. 18, 1900798, 18.09.2019.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review