Extending the Lotus Effect : Repairing Superhydrophobic Surfaces after Contamination or Damage by CHic Chemistry

Superhydrophobic surfaces have gained a reputation to show a self-cleaning behavior ("Lotus effect") as drops rolling off the surface take along loosely adhering dust particles. However, this self-cleaning process reaches its limits when such surfaces are brought in contact with sticky con...

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Publié dans:Langmuir : the ACS journal of surfaces and colloids. - 1985. - 34(2018), 29 vom: 24. Juli, Seite 8661-8669
Auteur principal: Hönes, Roland (Auteur)
Autres auteurs: Rühe, Jürgen
Format: Article en ligne
Langue:English
Publié: 2018
Accès à la collection:Langmuir : the ACS journal of surfaces and colloids
Sujets:Journal Article
Description
Résumé:Superhydrophobic surfaces have gained a reputation to show a self-cleaning behavior ("Lotus effect") as drops rolling off the surface take along loosely adhering dust particles. However, this self-cleaning process reaches its limits when such surfaces are brought in contact with sticky contaminants such as oils and smaller particles. Once intimate contact is established between the surface and a small particle, it will be almost impossible to remove it because of strong surface interactions. Such contaminations, however, lead to contact line pinning and destroy the superhydrophobic effect. Because the fragility of the micro- and nanostructures prohibits any mechanical cleaning, the sample is usually doomed. Here, we report a universal method for restoring superhydrophobicity: by simple dip-coating, a conformal ultrathin layer (≈10 nm) of a highly hydrophobic and photoreactive fluoropolymer is deposited. Through short UV irradiation (5 min), this thin layer is cross-linked and chemically attached to the underlying surface by C,H-insertion cross-linking, thus covering the contaminant like a thin veil. We use this "cover-up" strategy of masking the contaminants to restore superhydrophobicity. We demonstrate this principle by deliberately soiling the surface with various model contaminants, such as oily substances and particles, and study the repair process
Description:Date Completed 26.09.2018
Date Revised 26.09.2018
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1520-5827
DOI:10.1021/acs.langmuir.8b01179