Plastron Regeneration on Submerged Superhydrophobic Surfaces Using In Situ Gas Generation by Chemical Reaction
Name
GHM284.pdf
Description
Accepted version
Size
6 MB
Format
Adobe PDF
Checksum (MD5)
5e51f35e066644295ee124e42f28c411
Author(s)
Panchanathan, Divya
Rajappan, Anoop
Varanasi, Kripa
McKinley, Gareth H
Date Issued
September 2018
Journal
ACS Applied Materials & Interfaces
Publisher
American Chemical Society (ACS)
Citation
Panchanathan, Divya et al. "Plastron Regeneration on Submerged Superhydrophobic Surfaces Using In Situ Gas Generation by Chemical Reaction." ACS Applied Materials & Interfaces 10, 39 (September 2018): 33684-33692
© 2018 American Chemical Society
Version
Author's final manuscript
Abstract
Superhydrophobic surfaces submerged under water appear shiny due to total internal reflection of light from a thin layer of air (plastron) trapped in their surface texture. This entrapped air is advantageous for frictional drag reduction in various applications ranging from microfluidic channels to marine vessels. However, these aerophilic textures are prone to impregnation by water due to turbulent pressure fluctuations from external flows and dissolution of the trapped gas into the water. We demonstrate a novel chemical method to replenish the plastron in situ by using the decomposition reaction of hydrogen peroxide on superhydrophobic surfaces prepared with a catalytic coating. We also provide a thermodynamic framework for designing superhydrophobic surfaces with optimal texture and chemistry for underwater plastron regeneration. We finally demonstrate the practical utility of this method by fabricating periodic microtextures on aluminum surfaces that incorporate a cheap catalyst, manganese dioxide. We perform drag-reduction experiments under turbulent flow conditions in a Taylor-Couette cell (TC cell), which show that more than half of the drag increase ensuing from plastron collapse can be recovered spontaneously by injection of dilute H₂O₂ into the TC cell. Thus, we present a low-cost, scalable method to enable in situ plastron regeneration on large surfaces for marine applications.
MIT Department
Massachusetts Institute of Technology. Department of Mechanical Engineering
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Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
https://doi.org/10.1021/acsami.8b12471
