Superhydrophobic nanocomposite surface topography and ice adhesion

Area of Science:

• Materials Science
• Surface Engineering
• Nanotechnology

Background:

• Superhydrophobic coatings are crucial for preventing ice formation.
• Reducing surface roughness is key to enhancing superhydrophobic performance.
• Spray-casting offers a scalable method for coating fabrication.

Purpose of the Study:

• To demonstrate a method for reducing the surface roughness of spray-casted polyurethane/silica/fluoroacrylic superhydrophobic nanocomposite coatings.
• To investigate the relationship between surface roughness parameters and ice adhesion.
• To produce the smoothest superhydrophobic surface using spray-based techniques.

Main Methods:

• Optimized slurry carrier fluid, fluoropolymer medium, surface pretreatment, and spray parameters.
• Achieved arithmetic surface roughness values of 8.7, 2.7, and 1.6 μm.
• Evaluated ice adhesion using a pressurized tensile test after ice accretion from supercooled water spray.

Main Results:

• Three superhydrophobic surfaces with varying roughness were produced, with the smoothest at 1.6 μm.
• All superhydrophobic surfaces exhibited lower ice adhesion than polished aluminum.
• The intermediate roughness surface showed the best ice-phobic performance, indicating improved kurtosis and shorter autocorrelation lengths.

Conclusions:

• Spray-based techniques can effectively reduce surface roughness in superhydrophobic nanocomposite coatings.
• Surface topography, specifically kurtosis and autocorrelation length, significantly influences ice adhesion.
• The developed superhydrophobic coatings demonstrate potential for reducing ice adhesion by up to 60%.