Thermoregeneration of Plastrons on Superhydrophobic Coatings for Sustained Antifouling Properties

• Published in: Advanced engineering materials 2020-03, Vol.22 (3), p.n/a
• Main Authors: Simovich, Tomer, Rosenhahn, Axel, Lamb, Robert N.
• Format: Article
• Language: English
• Subjects: air layers; antifouling; gas solubilities; plastrons; superhydrophobic
• ISSN: 1438-1656; 1527-2648
• DOI: 10.1002/adem.201900806

A popular and desirable function of superhydrophobic coatings is their remarkable ability to retain an entrapped layer of air, called a plastron, when submerged underwater. The drawback is that the air layer is short‐lived due to solvation into the surrounding liquid. While manipulating the solubility of gases using temperature is a possible approach, it generally requires inefficiently heating large volumes of water. Following the demonstrated ability to maintain air bubbles on superhydrophobic surfaces for drag reduction, this article introduces a novel method of extracting gas from water to replenish and stabilize the plastron on superhydrophobic surfaces for sustained antifouling abilities. This method involves locally heating the liquid surrounding a superhydrophobic coating, reducing gas solubility, and causing the gas to nucleate at the liquid–air interface. The approach requires a relatively low energy input, due to the small volume of locally heated water. With a constant supply of equilibrated water and minimal energy input, the plastron can survive indefinitely without the need for a mechanical delivery of air. The thermoregenerating superhydrophobic samples were shown to exhibit excellent antifouling behavior and inhibited diatom attachment over a period of 5 days. A novel method of promoting the nucleation of dissolved gas in water is reported. The extracted gas is used to replenish and stabilize the entrapped air layer on superhydrophobic surfaces for sustained antifouling, rust resistance, and drag reduction abilities. Energy‐efficient applications may be developed for local heating of the surrounding liquid.