Construction and properties of hydrogel microlayer on the surface of water-based self-polishing antifouling resin coating

Abstract

The hydration layer and low elastic modulus of hydrogel give it great potential for application in the field of marine antifouling. The combination of hydrogel materials with self-polishing antifouling resins will endow the self-polishing antifouling resins with more antifouling mechanisms. In this study, a self-polishing antifouling resin coating which can form hydrogel microlayer in water was prepared, and the structure of hydrogel microlayer was adjusted by adjusting the content of self-crosslinking monomer N-hydroxymethacrylamide (HAM). With the increase of HAM content, the hydrogel microlayer is more obvious. Meanwhile, the formation of hydrogel microlayer made the resin coating have better antifouling performance: the water-based self-polishing resin coating (HAM3) with significant hydrogel microlayers reduced the relative adsorption area of proteins from 41.48 % to 9.56 %, in comparison to the TIPSMA5 coating with an insignificant hydrogel microlayer, and the more obvious the hydrogel layer, the less number of algae attached to resin coating (The minimum attached number of Chlorella was 7.6 × 10²/mm² and Nitzschia closterium was 6.1 × 10²/mm²). The construction and reinforcement of the hydrogel microlayer enabled the coating to exhibit a slow release of the antifouling agent 4, 5-dichloro-2-octylisothiazolinone (The antifouling agent release rate of the HAM3 coating was reduced from 1.0 μg·cm⁻²·d⁻¹ for the TIPSMA5 coating to 0.15 μg·cm⁻²·d⁻¹), and the hydrogel microlayer also enabled the resin coating to exhibit good drag-reducing properties. The water-based self-polishing antifouling resin, capable of forming hydrogel microlayers, is of considerable importance for enhancing the performance of water-based antifouling coatings and reducing the cost of coatings.