# Superhydrophobic Coating Solutions for Deicing Control in Aircraft
## 1 Introduction
Moreover, the Cassie-Baxter state is a condition to be maintained to keep the icephobic properties through the Euler stability of the roughness, the surface asperities resistance to buckling upon water drop impacts. The huge work on structures and morphology including roughness on hierarchical scales is probably the most innovative approach in this field, considering the high level of manipulation at the micro-nano scale available. In the last 20 years high water-repellent surfaces have attracted the scientific community due to their wide potential applications in various research and technological fields [6; 7] (Figure 1). Lotus-leaf-inspired superhydrophobic surfaces (SHS) and Pitcher-plant-inspired slippery liquid-infused porous surfaces (SLIPS) are compared in this review work [8] providing the state-of-the-art bio-inspired icephobic coatings/surfaces aimed at aircraft icing mitigation Experiments [9] were carried out at Icing Research Tunnel of Iowa State University (i.e., ISU-IRT) facility aiming to evaluate SHS and SLIPS coatings effectiveness in decreasing or eliminating ice accretion and its impact over the surfaces of typical airfoil/wing models. Ice accretion was found to be hindered by both SHS and SLIPS where strong aerodynamic forces were present, while where these forces found a minimum like close to the airfoil stagnation line, ice formation was still found. This method for preventing ice buildup on aerodynamic surfaces and wings has been successfully demonstrated by combining icephobes with reduced surface heating in the leading edge vicinity. This experimental study assessed the durability of icicle coatings when exposed to rainfall, and the potential applications for preventing aircraft icing. Additionally, it was re-evaluated the impact of ice on erosion and its associated consequences by analyzing variations in ice adhesion forces and surface morphology of eroded surfaces coated with SHS and SLIPS. The findings of this research provide valuable insight into the fundamental physics behind developing anti-/deicing strategies and robust solutions for mitigating aircraft icing. Nevertheless, the impact of surface coatings on the performances and behavior of the fluids should be thoroughly tested before their use in the industry. Once introduced, new materials for coatings developed for passive ice protection systems undergo for testing with deicing fluids in facilities like the Anti-icing Materials International Laboratory (AMIL) where, more than 30 years, interactions with the ground deicing/anti-icing fluids have been tested before approval for aeronautic application. In this work, current test methods, like the Water Spray Endurance Test (WSET) and Aerodynamic Acceptance Test (AAT), have been carried out on different, commercial and not commercial, surface coatings, with ground deicing/anti-icing fluids: The application of the coating resulted in a decreased spreading, wetting and the endurance time of the commercial fluids. Moreover, the superhydrophobic coating could also avoid aerodynamic drawbacks coming with the reference fluid [2]. The conclusions and methodology of this study were used in the development of sections of the SAE AIR6232 (Society of Automotive Engineers, Aerospace Information Report n\({}^{\circ}\)6232) Aircraft Surface Coating Interaction with the Aircraft Deicing/Anti-icing Fluids standard. Cocaine composition is related to its chemistry, to low energy materials, but also aimed to avoid the constraints given by environmental issues, raised by the dispersion of solids and fluids in the air and ground, hardly recoverable and unpredictable long-term accumulation effects. Among new materials, the ice-repelling properties of superhydrophobic silicone rubber nanocomposite surfaces were created in [11] through either spin coating or spray-coating methods and examined through contact angle hysteresis (CAH), surface roughness, and icing conditions.