Bioinspired Nucleobase-Driven Nonswellable Adhesive and Tough Gel with Excellent Underwater Adhesion

Underwater adhesives have drawn much attention in the areas of industrial and biomedical fields. However, it is still demanding to construct a tough underwater gel-based adhesive completely based on chemical constitution. Herein, a nonswellable and high-strength underwater adhesive gel is successfully fabricated through the random copolymerization of acrylic acid, butyl acrylate, and acrylated adenine in dimethyl sulfoxide (DMSO). The underwater adhesive behavior is skillfully regulated through hydrophobic aggregation induced by water-DMSO solvent exchange. The adhesive gels exhibit an excellent adhesive behavior for polytetrafluoroethylene, plastics, metals, rubber, and glasses in air and various aqueous solutions, including deionized water, seawater, and acid and alkali solutions (pH = 3 and 10, respectively). Moreover, the adhesive gels exhibited robust mechanical performance and remarkable nonswellable behavior, which were particularly important for applications of gel-based adhesives in water. It is anticipated that the strategy of bioinspired nucleobase-assisted underwater adhesive gel via hydrophobic aggregation induced by solvent exchange would provide an inspiration for the development of underwater adhesives.