Icephobic behavior of a slippery coating containing nanoporous particles as lubricant-loaded carriers

Abstract

Lubricant-infused surfaces have received increased attention because of their icephobic characteristics. However, the rapid consumption of the lubricant negatively affects the life service of these surfaces. Here we introduced a novel icephobic strategy using the synergistic effect of combining three different anti-icing mechanisms, namely stress localization (matrix), slippery and the formation of unfrozen molecules. Therefore, we fabricated two lubricant-loaded carriers by incorporating silicone oil or hydroxyl‑terminated silicone oil within a hydrophobic nanoporous particles. Different quantities of lubricant-loaded carriers were then embedded into an alkoxysilane resin-dimethylpolysiloxane (PDMS) blend having optimized mechanical properties. Using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and the Brunauer, Emmett, and Teller (BET) method, we confirmed that both silicone oils were successfully loaded within the porous aerogels. However, the silicone oil–loaded carrier accommodated more lubricant within its structure than the hydroxyl‑terminated silicone oil, the coatings with hydroxyl‑terminated silicone oil exhibited a better anti-icing performance. This enhanced anti-icing property can be attributed to the formation of hydrogen bonds between the water molecules and the hydrophilic functional groups of the oil. These coatings also reduced ice accumulation on their surfaces. The coatings containing hydroxyl‑terminated silicone oil–loaded carriers had a lower ice adhesion strength regardless of their concentration in the filler relative to those containing the silicone oil–loaded carriers. An ice adhesion strength of 15.9 kPa was achieved using 15% hydroxyl‑terminated silicone oil–loaded carriers. Reduced ice adhesion in samples containing HTSO/A stems from producing localized stress (matrix), the slippery behavior of the surface and the formation of unfrozen molecules that are hydrogen-bonded with water molecules on their surfaces. The latter mechanism helps these coatings retain stable icephobic characteristics even after 20 icing/deicing cycles.