Water-responsive entangled underwater adhesives enable strong adhesion in natural dynamic water

Efficient adhesion in natural dynamic water could greatly facilitate human aquatic activities. However, the loss of adhesive molecules, the barrier of interfacial water and the difficulty of strong solidification in dynamic water environment hinder the adhesion in natural water in practice. Herein, inspired by the “3C” adhesive mode of marine sessile organisms, we propose a universal applicable concept of water-responsive entanglements (WARE) via a combination of the entanglements and responsiveness of polymers for developing dynamic water-applicable adhesives. We demonstrated that WARE-type adhesives underwent a 3C-mimetic adhesive process, including entangled constraint-mediated initial loss suppression, sufficient dehydration-facilitated underwater contact and water responsiveness-promoted underwater crosslinking, thus completing the adhesive process and achieving strong adhesion in dynamic water. Intriguingly, due to the facile synthesis methodology and unique adhesive mode, the WARE-type adhesives also exhibit traits desirable for practical applications, such as mass producibility, long-term storage, on-demand detachment, and recyclability. Taking common human aquatic activities as examples, we further show the effectiveness of the WARE-type adhesives through their strong adhesive performance in simplifying the underwater exploration process, repairing a broken boat and sealing a leaky underwater pipeline in emergency.