Dropwise Condensation on Soft Hydrophobic Coatings

Akshay Phadnis, Konrad Rykaczewski

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Promoting dropwise condensation (DWC) could improve the efficiency of many industrial systems. Consequently, a lot of effort has been dedicated to finding durable materials that could sustainably promote DWC as well as finding routes to enhance the heat transfer rate during this phase change process. Motivated by previous reports of substrate softening increasing droplet nucleation rate, here we investigated how mechanical properties of a substrate impact relevant droplet-surface interactions and DWC heat transfer rate. Specifically, we experimentally quantified the effect of hydrophobic elastomer's shear modulus on droplet nucleation density and shedding radius. To quantify the impact of substrate softening on heat transfer through individual droplets, we combined analytical solution of elastomer deformation induced by droplets with finite element modeling of the heat transfer process. By substituting these experimentally and theoretically derived values into DWC heat transfer model, we quantified the compounding effect of the substrate's mechanical properties on the overall heat transfer rate. Our results show that softening of the substrates below a shear modulus of 500 kPa results in a significant reduction in the condensation heat transfer rate. This trend is primarily driven by additional thermal resistance of the liquid posed by depression of the soft substrate.

Original languageEnglish (US)
Pages (from-to)12095-12101
Number of pages7
JournalLangmuir
Volume33
Issue number43
DOIs
StatePublished - Oct 31 2017

Fingerprint

Condensation
condensation
heat transfer
Heat transfer
coatings
Coatings
Substrates
softening
Elastomers
elastomers
Nucleation
Elastic moduli
nucleation
mechanical properties
shear
compounding
Mechanical properties
thermal resistance
Heat resistance
surface reactions

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Spectroscopy
  • Electrochemistry

Cite this

Dropwise Condensation on Soft Hydrophobic Coatings. / Phadnis, Akshay; Rykaczewski, Konrad.

In: Langmuir, Vol. 33, No. 43, 31.10.2017, p. 12095-12101.

Research output: Contribution to journalArticle

Phadnis, Akshay ; Rykaczewski, Konrad. / Dropwise Condensation on Soft Hydrophobic Coatings. In: Langmuir. 2017 ; Vol. 33, No. 43. pp. 12095-12101.
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