A facile and universal method to fabricate ceramic coatings with tunable hydrophobicity and water adhesion
Thursday, May 27, 2021: 11:00 AM
Dr. Pengyun Xu
,
University of Toronto, Toronto, ON, Canada
Prof. Thomas W. Coyle
,
Centre for Advanced Coating Technologies (CACT), University of Toronto, Toronto, ON, Canada
Dr. Larry Pershin
,
University of Toronto, Toronto, ON, Canada
Prof. Javad Mostaghimi
,
University of Toronto, Toronto, ON, Canada
In this work, a facile and universal method to tune the hydrophobicity and water adhesion of various ceramic coatings was developed. A very common ceramic material, 7wt% yttria-stablized zirconia, was used to fabricate ceramic coatings via the suspension plasma spray (SPS) process. Micron-sized spheroidal cluster structures superimposed by nanometer-sized splats/particles were formed on the coating surface, generating the hierarchical structures. Isothermal annealing treatments were conducted, which changed the fine angular splats/particles on the as-sprayed coatings to large blunt aggregations by the sintering process. The morphology of the sintering-induced aggregations was controllable by tailoring the temperature and period of the isothermal annealing treatment. The as-sprayed coatings and annealed coatings with different surface structures were functionally modified to become hydrophobic by a quick immersion in stearic acid solution. The as-sprayed coatings were superhydrophobic with high water contact angle (WCA) and effortless water droplet rolling-off behavior. In contrast, the annealed coatings showed various kinds of hydrophobic behaviors depending on the extent of microstructural change, including different WCAs, roll-off angles, and water adhesion. This method can be applied on ceramic coatings with different materials, and shows great potential to tune the hydrophobicity and water adhesion of ceramic coatings smoothly and precisely.
