Strategy to construct polyzwitterionic hydrogel coating with antifouling, drag-reducing and weak swelling performance

-dimethylammonium betaine (PSBMA) and the typical polyelectrolyte effect of polyacrylic acid (PAA), a bicomponent hydrogel coating with weak swelling in saline solution was achieved, which could avoid peeling from solid substrates. The bicomponent hydrogel coating showed strong tensile properties and good compression performance and slipperiness. Although the large Young's modulus of the coating relatively weakens the drag reduction effect, entering the mixed lubrication region in low sliding rate is easy and a low friction coefficient at a high rate could thus be obtained. With the aid of silane coupling agent and weak deformation in water and saline solution, the hydrogel coating could be bound tightly on solid surfaces. After strong sandy water abrasion, the bicomponent hydrogel coating could maintain its original state without any cracks and peeling. The hydrogel coating exhibits good anti-bacterial adhesion and anti-protein adsorption. The bicomponent zwitterionic hydrogel coating reported here provides a new strategy for marine antifouling and drag reduction studies.