Cargando…

Resistant energy analysis of self-pulling process during dropwise condensation on superhydrophobic surfaces

Recently the development of superhydrophobic surfaces with one-tier or hierarchical textures has drawn increasing attention because enhanced condensation heat transfer has been observed on such biomimetic surfaces in well-tailored supersaturation or subcooling conditions. However, the physical mecha...

Descripción completa

Detalles Bibliográficos
Autores principales: Vandadi, Aref, Zhao, Lei, Cheng, Jiangtao
Formato: Online Artículo Texto
Lenguaje:English
Publicado: RSC 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9473257/
https://www.ncbi.nlm.nih.gov/pubmed/36133189
http://dx.doi.org/10.1039/c8na00237a
_version_ 1784789466667286528
author Vandadi, Aref
Zhao, Lei
Cheng, Jiangtao
author_facet Vandadi, Aref
Zhao, Lei
Cheng, Jiangtao
author_sort Vandadi, Aref
collection PubMed
description Recently the development of superhydrophobic surfaces with one-tier or hierarchical textures has drawn increasing attention because enhanced condensation heat transfer has been observed on such biomimetic surfaces in well-tailored supersaturation or subcooling conditions. However, the physical mechanisms underlying condensation enhancement are still less understood. Here we report an energy-based analysis on the formation and growth of condensate droplets on two-tier superhydrophobic surfaces, which are fabricated by decorating carbon nanotubes (CNTs) onto microscale fluorinated pillars. Thus-formed hierarchical surfaces with two tier micro/nanoscale roughness are proved to be superior to smooth surfaces in the spatial control of condensate droplets. In particular, we focus on the self-pulling process of condensates in the partially wetting morphology (PW) from surface cavities due to intrinsic Laplace pressure gradient. In this analysis, the self-pulling process of condensate tails is resisted by adhesion energy, viscous dissipation, contact line dissipation and line tension in a combined manner. This process can be facilitated by adjusting the configuration and length scale of the first-tier texture. The optimum design can not only lower the total resistant energy but also favor the out-of-plane motion of condensate droplets anchored in the first-tier cavity. It is also shown that engineered surface with hierarchical roughness is beneficial to remarkably mitigating contact line dissipation from the perspective of molecular kinetic theory (MKT). Our study suggests that scaling down surface roughness to submicron scale can facilitate the self-propelled removal of condensate droplets.
format Online
Article
Text
id pubmed-9473257
institution National Center for Biotechnology Information
language English
publishDate 2018
publisher RSC
record_format MEDLINE/PubMed
spelling pubmed-94732572022-09-20 Resistant energy analysis of self-pulling process during dropwise condensation on superhydrophobic surfaces Vandadi, Aref Zhao, Lei Cheng, Jiangtao Nanoscale Adv Chemistry Recently the development of superhydrophobic surfaces with one-tier or hierarchical textures has drawn increasing attention because enhanced condensation heat transfer has been observed on such biomimetic surfaces in well-tailored supersaturation or subcooling conditions. However, the physical mechanisms underlying condensation enhancement are still less understood. Here we report an energy-based analysis on the formation and growth of condensate droplets on two-tier superhydrophobic surfaces, which are fabricated by decorating carbon nanotubes (CNTs) onto microscale fluorinated pillars. Thus-formed hierarchical surfaces with two tier micro/nanoscale roughness are proved to be superior to smooth surfaces in the spatial control of condensate droplets. In particular, we focus on the self-pulling process of condensates in the partially wetting morphology (PW) from surface cavities due to intrinsic Laplace pressure gradient. In this analysis, the self-pulling process of condensate tails is resisted by adhesion energy, viscous dissipation, contact line dissipation and line tension in a combined manner. This process can be facilitated by adjusting the configuration and length scale of the first-tier texture. The optimum design can not only lower the total resistant energy but also favor the out-of-plane motion of condensate droplets anchored in the first-tier cavity. It is also shown that engineered surface with hierarchical roughness is beneficial to remarkably mitigating contact line dissipation from the perspective of molecular kinetic theory (MKT). Our study suggests that scaling down surface roughness to submicron scale can facilitate the self-propelled removal of condensate droplets. RSC 2018-12-20 /pmc/articles/PMC9473257/ /pubmed/36133189 http://dx.doi.org/10.1039/c8na00237a Text en This journal is © The Royal Society of Chemistry https://creativecommons.org/licenses/by/3.0/
spellingShingle Chemistry
Vandadi, Aref
Zhao, Lei
Cheng, Jiangtao
Resistant energy analysis of self-pulling process during dropwise condensation on superhydrophobic surfaces
title Resistant energy analysis of self-pulling process during dropwise condensation on superhydrophobic surfaces
title_full Resistant energy analysis of self-pulling process during dropwise condensation on superhydrophobic surfaces
title_fullStr Resistant energy analysis of self-pulling process during dropwise condensation on superhydrophobic surfaces
title_full_unstemmed Resistant energy analysis of self-pulling process during dropwise condensation on superhydrophobic surfaces
title_short Resistant energy analysis of self-pulling process during dropwise condensation on superhydrophobic surfaces
title_sort resistant energy analysis of self-pulling process during dropwise condensation on superhydrophobic surfaces
topic Chemistry
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9473257/
https://www.ncbi.nlm.nih.gov/pubmed/36133189
http://dx.doi.org/10.1039/c8na00237a
work_keys_str_mv AT vandadiaref resistantenergyanalysisofselfpullingprocessduringdropwisecondensationonsuperhydrophobicsurfaces
AT zhaolei resistantenergyanalysisofselfpullingprocessduringdropwisecondensationonsuperhydrophobicsurfaces
AT chengjiangtao resistantenergyanalysisofselfpullingprocessduringdropwisecondensationonsuperhydrophobicsurfaces