Transparent Double-layered antifogging hydrogel coating with high Mechanical-resistance and effective Anti-oil-fouling ability

Transparent substrates are frequently employed in a wide range of optical applications, such as eyeglasses, displays, and sensors. While these substrates should have superior optical qualities, they often encounter a number of problems including excessive fogging and surface contamination. Hydrogel is a good candidate for anti-fogging coating, however, its poor bonding with the substrates and high tendency of water loss have hindered its development. In this work, we have developed a dual-layered anti-fogging polyacrylamide (AAm1 + 2)@hydrogel coating on a variety of substrates by spin-coating technique with the inner layer (AAm1) chemically bonded to the substrates and retaining water for a long time and the outer layer (AAm2) wear-resistant to the external environment. This transparent hydrophilic hydrogel coating possessed a contact angle (CA) less than 90° and the same light transmittance as that of a bare glass. Besides, the coating can also successfully keep the fog away from obscuring the view through the cambered eyeglass lenses. The bio-inspired AAm1 + 2@ anti-fogging coating has demonstrated prolonged anti-fogging duration over a wide temperature range for repeated uses. Under normal use circumstances, the outer AAm2 layer can prevent scratch or abrasion damage. The coating was also extremely effective in decreasing ice adhesion and resisting fouling from oil contamination. This coating has offered lots of potential for use in numerous practical applications due to its variety of desired features that have been demonstrated and its straightforward production procedure.