Harrick Plasma → News & Research → Research →
Ice crystallization on electrical lines or airplane wings can disrupt operations and even endanger lives. A proposed technique to reduce ice crystallization involves slippery liquid-infused porous surfaces (SLIPS). These ice-repellent surfaces contain a layer of oil to delay ice formation. However, this oil layer is depleted over time, limiting the SLIPS’s long-term effectiveness. Additionally, it is still not clear how ice crystallization differs on SLIPS from non-SLIPS surfaces. These issues must be addressed to convert SLIPS from a laboratory novelty to widespread commercial use.
To investigate oil depletion in SLIPS, Gandee et al. fabricated SLIPS surfaces using aluminum plates and a variety of oils. Gandee created micro/nanostructures on T6 6061 aluminum plates by sandblasting and boehmitization. Next, Gandee used Harrick Plasma’s High Powered Plasma Cleaner (PDC-001-HP) to treat a portion of the plates before silanizing them and impregnating them with silicone oil. The other plates were impregnated with mineral oil or Krytox oils of varying viscosities. High viscosity oils (silicone, some Krytox oils) were more likely than low viscosity oils (mineral oil) to congregate in frozen water droplets on the SLIPS surfaces. Thus, high viscosity oils experience higher oil depletion rates, making them less suitable for SLIPS applications.
Gandee also examined ice crystallization on SLIPS compared with ice crystallization on (oil-free) hydrophilic/superhydrophobic surfaces. On the hydrophilic and superhydrophobic surfaces, ice crystals formed in pointy, sharply-defined dendritic patterns. In contrast, the dendrites on SLIPS surfaces containing either silicone, mineral, Krytox, or hydroxy-PDMS oils were thick and lumpy without patterns. This difference is attributed to oil wicking from the SLIPS surfaces into the frozen water droplets. Insights gained from Gandee’s study could help develop SLIPS for widespread deicing applications.
Ice Crystallization Articles
Gandee H, Zhou Y, Lee J, Chomali J, Xu H, and Adera S. “Unique ice dendrite morphology on state-of-the-art oil-impregnated surfaces”. Proceedings of the National Academy of Sciences 2023 120:1 10.1073/pnas.2214143120