Self‐Repairing Performance of Slippery Liquid Infused Porous Surfaces for Durable Anti‐Icing

Abstract

Anti-icing fluids with a low freezing point, such as ethylene glycol, are widely used for aircraft. [9] The fluid is evenly sprayed on the aircraft surface, thereby reducing the freezing point of water droplets and delaying icing. However, the anti-icing fluid needs to be applied repeatedly and requires many raw materials. Consequently, the deposition and dissipation of ethylene glycol aqueous solutions has caused serious pollution to the soil and groundwater environment. [10] Recently, superhydrophobic surfaces (SHP) have attracted much attention in the field of anti-icing. [11] The SHP can trap air within the micro/nanosurface and barrier the heat transfer, [12] thus showing a Cassie state. Such surfaces can repel water drops and delay the ice nucleation, which endows them excellent anti-icing properties. However, SHP is currently unable to meet the anti-icing requirements of aircraft surfaces well. On one hand, the aircraft must pass through clouds with high water vapor content during flight, and the water can condense on the textured structure of SHP, resulting in a Wenzel state. [13] On the other hand, the supercooled water droplets will impact onto the surface of the aircraft running at high speed. Thus, the water droplets can penetrate into the textured structure of SHP, which can also lead to a Wenzel state. [14] In the Wenzel state, the ice forms an interlock with the textured surface, consequently resulting in a higher ice-adhesion strength of SHP. [15] As a result, the SHP does not mean icephobicity, especially for the in-flight icing scenario.Inspired by nepenthes, Aizenberg et al. prepared a slippery liquid infused porous surface (SLIPS), also known as an ultralubricating surface. [16] SLIPS can be created by infiltrating a porous substrate with lubricant to produce an ultra-smooth lubricant layer and this layer on the surface can suppress the anchor of ice into the solid surface. Thus, the SLIPS demonstrates low ice-adhesion [17] and low nucleation rate. [18] Silicone oil (viscosity: 50 mPa s at 25 °C, surface tension: 21.2 mN m -1 at 25 °C, density: 0.964 g cm -1 at 25 °C, vapor pressure: <7 hPa at 25 °C) is often used as the lubricant, because it is difficult to volatile, non-toxic, harmless and low price. Anodic oxidation with simplicity and efficiency is generally used for the construction of the porous surfaces of light metal materials, [19] which can be also used for preparing SLIPS. To sum up, SLIPS is an economical, convenient, low-power requirement and environmentally friendly passive anti-icing method. Additionally, the Icing accretion on aircraft surfaces has threatened the flight safety so far. Slippery liquid infused porous surface (SLIPS) is an emerging anti-icing method. Many studies have found that SLIPS has self-repairing phenomena. However, there is almost no systematic research on the number of selfrepairs in service, which determines the durability of anti-icing. Herein, the self-repairing performance of SLIPS is studied through icing-repairing and abrasion-repairing cycles. A st...

Key Factors Affecting Durable Anti-Icing of Slippery Surfaces: Pore Size and Porosity

“…This indicates that the lubricant on the smooth surface is rapidly consumed during the frosting/defrosting process, resulting in weak water droplet mobility, which is consistent with the literature studies. 44,45 The CAH of nanostructured SLIPSs during the cycles rose more slowly than that of SLIPS prepared by MS. The nanostructure provides stronger capillary retention than the microstructure, reducing lubricant depletion during frosting.…”

Robust and durable liquid-repellent surfaces

“…In addition, imparting SLISs with self-healing property (Section 4.4) can also be an alternative method to improve their ice-phobicity for long-term icing/de-icing applications. 56,579 Although liquid-repellent surfaces show remarkable anti-icing property, ice eventually forms on even the best liquid-repellent surfaces under extreme conditions, making de-icing a key consideration for the evaluation of ice-phobicity. Typically, shearing the ice from a surface using a force probe, or removing the ice using centrifugation are two most widely used techniques to measure ice adhesion strength.…”

“…In addition, imparting SLISs with self-healing property (Section 4.4) can also be an alternative method to improve their ice-phobicity for long-term icing/de-icing applications. 56,579…”

Effect of Polydimethylsiloxane Oil Lubrication on the Friction of Cross-Country UHMWPE Ski Bases on Snow

“…PDMS is considered non-toxic and is used as anti-foaming additives in foods, cosmetics, and other domestic applications. Silicone oils have previously been used in reduced ice adhesion applications (Yeong et al, 2016 ), as lubricants for hard icephobic coatings (Zheng et al, 2022 ) and in self-repairing slippery liquid-infused porous surfaces (SLIPS) (Yuan et al, 2022 ).…”