Viscous, Hofmeister Effect‐Enhanced Macromolecular Adhesives for Effective Bonding in Seawater

Deployment of adhesives in natural seawater to in situ bonds is urgently needed in engineering fields. However, stable adhesion in natural seawater remains a challenge due to the turbulent environment and high ion concentration. Herein, we reported a viscous, macromolecular underwater adhesive enhanced by Hofmeister effect (EHUA) for practical application in dynamic seawater. EHUA was synthesized via a facile one-step copolymerization. After transferred into seawater, the solvent of EHUA was exchanged to seawater, and thereby hydrogen bonds inside the adhesive were activated and enhanced by Hofmeister effect. We demonstrated EHUA can adhere on the surface in turbulent seawater, and the adhesive strength could reach 1.691 MPa. In addition, the adhesives also exhibited long-term storage stability and convenient recyclability. These fascinating properties enable adhesives to seal leaky pipelines, repair damaged ships and construct buildings in turbulent seawater. This work may open an avenue for the design of adhesives for seawater environments.