Characterization of Methyl-Functionalized Silica Nanosprings for Superhydrophobic and Defrosting Coatings

Thin non-perfluoroalkoxy superhydrophobic coatings are desirable for heat exchangers because of their lower thermal resistance and reduced environmental concerns. Coatings requirements must also include robustness and longevity and facilitate high defrosting rates in refrigeration applications to wa...

Full description

Saved in:
Bibliographic Details
Published in:ACS applied materials & interfaces 2019-01, Vol.11 (4), p.4607-4615
Main Authors: Corti, Giancarlo, Schmiesing, Nickolas C, Barrington, Griffin T, Humphreys, Morgan G, Sommers, Andrew D
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Thin non-perfluoroalkoxy superhydrophobic coatings are desirable for heat exchangers because of their lower thermal resistance and reduced environmental concerns. Coatings requirements must also include robustness and longevity and facilitate high defrosting rates in refrigeration applications to warrant their adoption and use. Methyl-functionalized silica nanosprings (SN) possess water droplet static contact angles above 160° with contact angle hysteresis values as low as 6.9° for a sub-micrometer-thick coating. The methyl functional groups render the silica surface hydrophobic, whereas the geometrical and topographical characteristics of the nanosprings make it super-hydrophobic. Results show that SN are capable of removing 95% of the frost from the surface at a lower temperature than the base aluminum substrate. The sub-micrometer SN coating also decreases the time to defrost by ≈1.5 times and can withstand more than 20 frosting–defrosting cycles in a high humidity environment akin to real working conditions for heat exchangers.
ISSN:1944-8244
1944-8252
DOI:10.1021/acsami.8b18873