Solution precursor plasma sprayed yttrium oxide coatings with reversible transition between superhydrophilic and superhydrophobic wettability

Monday, May 27, 2019: 11:40
Annex Hall/F204 (Pacifico Yokohama)
Prof. Thomas W. Coyle , University of Toronto, Toronto, ON, Canada
Mr. Pengyun Xu , University of Toronto, Toronto, ON, Canada
Dr. Larry Pershin , University of Toronto, Toronto, ON, Canada
Prof. Javad Mostaghimi , University of Toronto, Toronto, ON, Canada

Plasma-sprayed yttrium oxide coatings are commonly used in protective applications such as corrosion resistant coatings, plasma erosion resistant coatings, and yttria-doped zirconia thermal barrier coatings, while the wettability of yttria coatings is seldom investigated. In this work, hierarchically-structured and nano-structured yttrium oxide coatings were deposited via solution precursor plasma spray (SPPS) process using yttrium nitrate solution as feedstock. The superhydrophilic yttrium oxide coatings became superhydrophobic after overnight vacuum treatment, showing a very large water contact angle of ~160o, a very small roll-off angle of ~6o, and complete water droplet rebound behaviors. The superhydrophobic coating became superhydrophilic rapidly after short-period high temperature treatment or Ar-plasma cleaning, while the coating regained superhydrophobicity after vacuum treatment showing reversible wettability. The xylene atmosphere exposure of yttrium oxide coatings were investigated which generated similar wettability transition with vacuum treatment, indicating the organic contamination on the coating surface resulted in the reversible wettability. Powder plasma sprayed yttrium oxide coatings were compared with the SPPS coatings to investigate the effect of nano-scaled roughness, coating structures and topographies on the wettability.

See more of: New Coating Materials Development I
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