Construction of silane-modified polyampholyte hydrogel coatings for multi-scale antibiofouling

The antifouling capabilities of zwitterionic hydrogels have been well established, yet, drawbacks such as single antifouling performance and osmotic pressure-driven swelling in water, which lead to poor mechanical properties and low bonding strength, respectively, remain obstacles to practical applications. In this work, silane-modified polyampholyte (S-PA)-based hydrogel coatings with high adhesive strength and multi-scale antifouling ability were prepared by introducing silane onto the hydrogel surfaces. The resulting S-PA hydrogel coatings exhibited as high as 1980 J m⁻² adhesion, due to the covalent bonding between the vinyl groups in PA and silanols in silane molecules. Furthermore, the S-PA hydrogel coatings demonstrated good protein adsorption resistance (the protein adsorption capacity of bovine serum protein was 5 mg g⁻¹) and bacteriostatic ability, which endows the coating's multi-scale antifouling effect together with its excellent anti-diatom adhesion property (the adhesion area of navicular on S-PA hydrogel was as low as 7.43 mm²). The high adhesive strength and multi-scale antifouling ability of the S-PA hydrogel coatings presented in this work may provide a new route toward marine antifouling strategies.