Different Approaches to Low-Wettable Materials for Freezing Environments: Design, Performance and Durability

Ice nucleation and accretion leads to multiple problems such as freezing of the streets which can cause traffic collisions or people injuries, and collapse of high voltage power lines leading to black-out and icing of aircraft components, causing major aeronautic accidents. The most widespread strategies for the removal of accumulated ice layers result in most cases being expensive, timeconsuming and hazardous for the environment. In this work we present the design of hydrophobic hybrid inorganic-organic coatings via Lotus leaf-like and slippery liquid infused porous surfaces (SLIPS) approaches with reduced, lasting wetting performance in cold environments. Static and dynamic wetting behavior was evaluated at room and sub-zero temperatures. The main target was the selection of the most suitable design approaches and formulations of coatings to be applied on metals or alloys when the contact time between the droplet and the material surface has to be minimized. In the temperature range from -10 to 0°C, we report evidence of a stable hydrophobicity and a low water contact angle hysteresis (below 15) of all the SLIPS developed. The surfaces' ability to keep their wetting performance unchanged during the freeze/and frost/thaw durability cycles stood out as a key issue for further development at larger scale.