This experiment was conducted to determine if a super-hydrophobic surface repels ice. I believe that the surfaces with higher contact angles (and thus higher hydrophobicity) repel ice more effectively than the surfaces with lower contact angles.
Naturally-occurring super-hydrophobic surfaces provide good models for constructing an artificial copy. An investigation of the surface structure of lotus leaves enabled the design of a bionic super-hydrophobic surface coating made with Teflon micro-particles coated onto metal plates using an adhesive layer.
Six super-hydrophobic surfaces were fabricated with different adhesives and the contact angle of each was measured to determine its hydrophobicity.
The best hydrophobic surface was identified to have a contact angle of 170° and its practical applications were tested by applying it to the rotor blades of a model helicopter.
It was found that a super-hydrophobic surface with a well-designed surface micro-structure does repel ice.
A surface with higher hydrophobicity is more efficient at repelling ice; a surface with a contact angle of less than 140° only has a limited ice-repelling capability, while a surface with a high contact angle (170°) is an effective anti-icing surface.
The super-hydrophobic coating was then applied to a rotor blade of a model helicopter.
When tested in both on-the-ground and in-flight conditions, the rotor blade with the coating was free from ice while ice accumulated on the control blade without the coating.
This project confirmed that a well-designed super-hydrophobic surface does repel ice and that a surface with a higher contact angle is more efficient at repelling ice.
The super-hydrophobic surface applied on a model helicopter did prevent ice formation in both on-the-ground and in-flight scenarios.
This data suggests that icing problems in many other applications can be prevented using a super-hydrophobic surface coating.
This project examines the ice-repelling capabilities of super-hydrophobic surfaces made with Teflon micro-particles and different adhesives; it also explores the applications of this ice-repelling surface in preventing icing on helicopters.
Science Fair Project done By Haotian Xu