Superoleophobic Surfaces through Control of Sprayed-on Stochastic Topography

The liquid repellency and surface topography characteristics of coatings comprising a sprayed-on mixture of fluoroalkyl-functional precipitated silica and a fluoropolymer binder were examined using contact and sliding angle analysis, electron microscopy, and image analysis for determination of fract...

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Bibliographic Details
Main Authors: Campos, Raymond, Guenthner, Andrew J., Meuler, Adam J., Tuteja, Anish, Cohen, Robert E., McKinley, Gareth H., Haddad, Timothy S., Mabry, Joseph M.
Other Authors: Massachusetts Institute of Technology. Department of Chemical Engineering
Format: Article
Language:en_US
Published: American Chemical Society (ACS) 2013
Online Access:http://hdl.handle.net/1721.1/80808
https://orcid.org/0000-0001-8323-2779
https://orcid.org/0000-0003-1085-7692
Description
Summary:The liquid repellency and surface topography characteristics of coatings comprising a sprayed-on mixture of fluoroalkyl-functional precipitated silica and a fluoropolymer binder were examined using contact and sliding angle analysis, electron microscopy, and image analysis for determination of fractal dimensionality. The coatings proved to be an especially useful class of liquid repellent materials due to their combination of simple and scalable deposition process, low surface energy, and the roughness characteristics of the aggregates. These characteristics interact in a unique way to prevent the buildup of binder in interstitial regions, preserving re-entrant curvature across multiple length scales, thereby enabling a wide range of liquid repellency, including superoleophobicity. In addition, rather than accumulating in the interstices, the binder becomes widely distributed across the surface of the aggregates, enabling a mechanism in which a simple shortage or excess of binder controls the extent of coating roughness at very small length scales, thereby controlling the extent of liquid repellence.