The Relationship between Water Wetting and Ice Adhesion

Ice accretion on aircraft leads to difficulties in aircraft flight control due to weight increase and change in weight distribution. Conventionally these difficulties are overcome using anti-icing or de-icing products, such as freezing depressants and heating devices. A more cost effective way to solve these problems would be to use ice repellent surfaces (ice-phobic). As a first step in this direction the relationship between water wettability and ice adhesion was investigated. Using the appropriate chemistry and tailoring the surface roughness a variety of polycarbonate-coated surfaces were created: these included ultra-hydrophilic and ultra-hydrophobic surfaces and surfaces with surface properties in between the extreme ultra-surfaces. Ice adhesion tests and contact angle measurements indicated that the higher the contact angle the lower is the adhesion of ice. The best results were obtained in the case of ultra-hydrophobic surface treatment that led to an 18 fold decrease in ice adhesion compared to the untreated aluminum surface. (C) Koninklijke Brill NV, Leiden, 2009