Anti-Icing Properties of Surface Coatings Imparting Varying Levels of Hydrophobicity

Anti-icing surfaces are generally characterized by their contact angle, which quantifies to what degree a water droplet is adhered to the surface. Surfaces that exhibit very high contact angles are typically expected to either prevent ice accumulation or have lower ice adhesion strength. The objective of this experiment is to investigate the anti-icing properties of nine sheets of coated aluminum through supercooled droplet impingement testing. These sheets are provided by Dr. Christopher Wohl of NASA, each of which had a different coating to impart various levels of surface roughness and contact angles. In order to characterize these surfaces, a cold chamber is constructed, and both -5 degrees C distilled water droplets and -8 degrees C water droplets with a salinity of 35 ppt. are released from heights of 30 cm and 1 m and impact onto -20 degrees C surfaces. These tests are conducted in an environment with relative humidity values ranging from 35% to 45%, allowing for frost formation on the surfaces prior to droplet impact. Under the parameters tested, none of the surfaces were able to completely rebound the droplets. Some surfaces exhibited the ability to delay the freezing time of the droplet, partially rebound of smaller droplets, and even reform the droplet after impact. The results of this study conclude that the surfaces with the lower contact angles exhibited superior anti-icing properties to those surfaces with larger contact angles.

Author

• Richer, Sarah E.

Language

• en

Keyword

• Hydrophobic
• Anti-Icing
• Icephobic

Date created

• 2015

Type of Work

• Master's Thesis

License

• All rights reserved

Rights statement

• In Copyright

GW Unit

• Mechanical & Aerospace Engineering

Degree

• M.S.

Advisor

• Leftwich, Megan
• Bardet, Philippe M.

Committee Member(s)

• Fullerton, Anne M.
• Wickenheiser, Adam M.

Persistent URL

•  https://scholarspace.library.gwu.edu/etd/fb4948535