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Superhydrophobic Ceramic Coatings by Solution Precursor Plasma Spray.

Cai Y, Coyle TW, Azimi G, Mostaghimi J - Sci Rep (2016)

Bottom Line: A rare earth oxide (REO) was selected as the coating material due to its hydrophobic nature, chemical inertness, high temperature stability, and good mechanical properties, and deposited on stainless steel substrates by solution precursor plasma spray (SPPS).The as-sprayed coating demonstrated a hierarchically structured surface topography, which closely resembles superhydrophobic surfaces found in nature.The water contact angle on the SPPS superhydrophobic coating was up to 65% higher than on smooth REO surfaces.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, ON, M5S 3G8, Canada.

ABSTRACT
This work presents a novel coating technique to manufacture ceramic superhydrophobic coatings rapidly and economically. A rare earth oxide (REO) was selected as the coating material due to its hydrophobic nature, chemical inertness, high temperature stability, and good mechanical properties, and deposited on stainless steel substrates by solution precursor plasma spray (SPPS). The effects of various spraying conditions including standoff distance, torch power, number of torch passes, types of solvent and plasma velocity were investigated. The as-sprayed coating demonstrated a hierarchically structured surface topography, which closely resembles superhydrophobic surfaces found in nature. The water contact angle on the SPPS superhydrophobic coating was up to 65% higher than on smooth REO surfaces.

No MeSH data available.


Related in: MedlinePlus

Topography and dynamic impacts of water droplets on the coated surface.(a) SEM image of the surface of a superhydrophobic quaking aspen leaf shows a hierarchically structured surface. (b) SEM image of the surface of a coating deposited under condition 12 exhibits a similar surface topography. (c) Change in wetting behaviours of the coating under various conditions. Sample size is 25.4 mm in diameter. (d) Dynamic impact of a single water droplet (top panel) and coalescence of 2 droplets (bottom panel) on the coated surface, scale bar 2 mm (see Supplementary Movies S1 and S2).
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f3: Topography and dynamic impacts of water droplets on the coated surface.(a) SEM image of the surface of a superhydrophobic quaking aspen leaf shows a hierarchically structured surface. (b) SEM image of the surface of a coating deposited under condition 12 exhibits a similar surface topography. (c) Change in wetting behaviours of the coating under various conditions. Sample size is 25.4 mm in diameter. (d) Dynamic impact of a single water droplet (top panel) and coalescence of 2 droplets (bottom panel) on the coated surface, scale bar 2 mm (see Supplementary Movies S1 and S2).

Mentions: A uniform distribution of micro-scale irregular clusters ranging from 5 microns to 30 microns in size was observed on the surface of the coating (Fig. 3b and Supplementary Fig. S5). The clusters are agglomerates of individual particles less than 100 nm in diameter. This topography is consistent with the cross sectional images of the coating. The hierarchical structured top surface of the coating with a multi-scale roughness is very similar to the surface of superhydrophobic leaves in nature, such as the quaking aspen leaf (Fig. 3a). The as-sprayed coating surface was initially hydrophilic, but after vacuum treatment at 1 Pa for 48 hours the coating surface became superhydrophobic as shown in Fig. 3c. This transition is believed to be dependent on the surface oxygen-to-metal ratio15. The combination of the surface structure and the intrinsic hydrophobicity of the material gives the coating an excellent water repellent property (Fig. 3d).


Superhydrophobic Ceramic Coatings by Solution Precursor Plasma Spray.

Cai Y, Coyle TW, Azimi G, Mostaghimi J - Sci Rep (2016)

Topography and dynamic impacts of water droplets on the coated surface.(a) SEM image of the surface of a superhydrophobic quaking aspen leaf shows a hierarchically structured surface. (b) SEM image of the surface of a coating deposited under condition 12 exhibits a similar surface topography. (c) Change in wetting behaviours of the coating under various conditions. Sample size is 25.4 mm in diameter. (d) Dynamic impact of a single water droplet (top panel) and coalescence of 2 droplets (bottom panel) on the coated surface, scale bar 2 mm (see Supplementary Movies S1 and S2).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835754&req=5

f3: Topography and dynamic impacts of water droplets on the coated surface.(a) SEM image of the surface of a superhydrophobic quaking aspen leaf shows a hierarchically structured surface. (b) SEM image of the surface of a coating deposited under condition 12 exhibits a similar surface topography. (c) Change in wetting behaviours of the coating under various conditions. Sample size is 25.4 mm in diameter. (d) Dynamic impact of a single water droplet (top panel) and coalescence of 2 droplets (bottom panel) on the coated surface, scale bar 2 mm (see Supplementary Movies S1 and S2).
Mentions: A uniform distribution of micro-scale irregular clusters ranging from 5 microns to 30 microns in size was observed on the surface of the coating (Fig. 3b and Supplementary Fig. S5). The clusters are agglomerates of individual particles less than 100 nm in diameter. This topography is consistent with the cross sectional images of the coating. The hierarchical structured top surface of the coating with a multi-scale roughness is very similar to the surface of superhydrophobic leaves in nature, such as the quaking aspen leaf (Fig. 3a). The as-sprayed coating surface was initially hydrophilic, but after vacuum treatment at 1 Pa for 48 hours the coating surface became superhydrophobic as shown in Fig. 3c. This transition is believed to be dependent on the surface oxygen-to-metal ratio15. The combination of the surface structure and the intrinsic hydrophobicity of the material gives the coating an excellent water repellent property (Fig. 3d).

Bottom Line: A rare earth oxide (REO) was selected as the coating material due to its hydrophobic nature, chemical inertness, high temperature stability, and good mechanical properties, and deposited on stainless steel substrates by solution precursor plasma spray (SPPS).The as-sprayed coating demonstrated a hierarchically structured surface topography, which closely resembles superhydrophobic surfaces found in nature.The water contact angle on the SPPS superhydrophobic coating was up to 65% higher than on smooth REO surfaces.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, ON, M5S 3G8, Canada.

ABSTRACT
This work presents a novel coating technique to manufacture ceramic superhydrophobic coatings rapidly and economically. A rare earth oxide (REO) was selected as the coating material due to its hydrophobic nature, chemical inertness, high temperature stability, and good mechanical properties, and deposited on stainless steel substrates by solution precursor plasma spray (SPPS). The effects of various spraying conditions including standoff distance, torch power, number of torch passes, types of solvent and plasma velocity were investigated. The as-sprayed coating demonstrated a hierarchically structured surface topography, which closely resembles superhydrophobic surfaces found in nature. The water contact angle on the SPPS superhydrophobic coating was up to 65% higher than on smooth REO surfaces.

No MeSH data available.


Related in: MedlinePlus