University of Illinois Urbana-Champaign

Microscopic Hierarchical Condensation

Fazle Rabbi, Kazi

Content Files
Fazle_Rabbi_Kazi.jpg

Permalink

https://hdl.handle.net/2142/109751

Description

Title
Microscopic Hierarchical Condensation
Author(s)
Fazle Rabbi, Kazi
Issue Date
2021
Keyword(s)
  • Condensation Heat
  • Thermoelectric Power Generation
Date of Ingest
2021-04-12T22:32:13Z
Abstract
The attainment of ultra-high condensation heat transfer has been a decades-old pursuit due to its potential to enhance the efficiency of thermoelectric power generation, high heat flux thermal management, water harvesting and distillation. To enhance condensation by enabling ultra-efficient droplet removal, we demonstrate condensation on rationally designed hierarchical superhydrophobic surfaces consisting of hill-like microstructures covered with nanostructures that enable large (∼100 μm) spherical condensate droplets on top of the microstructures to coexist with underlying smaller (<10 μm) shadow droplets. Termed hierarchical condensation, the approach combines the spontaneous coalescence of the larger suspended Cassie–Baxter droplets with its shadow droplets residing beneath. We use high-speed optical microscopy and focal plane shift imaging to show that hierarchical condensation is capable of efficiently removing the sub-10-μm condensate droplets via both coalescence and divergent-track-assisted droplet self-transport toward the large suspended Cassie–Baxter state droplets. In addition, experimental growth rate analysis showed that the presence of the large CB droplets accelerates individual underlying shadow droplet growth by ∼21% when compared to identically sized droplets not residing beneath Cassie–Baxter droplets.
Type of Resource
Image
Genre of Resource
Photograph
Language
eng
Permalink
http://hdl.handle.net/2142/109751
Copyright and License Information
Copyright 2021 Kazi Fazle Rabbi

Owning Collections

Image of Research - Graduate Students PRIMARY