Polycatechol Triblock Copolymers Form Exceptionally Strong Wet Adhesives

Marine organisms such as mussels and sandcastle worms secrete glue proteins that enable robust wet adhesion and curing properties. The adhesive and curing attributes of these proteins have been ascribed to the presence of catecholic 3,4-dihydroxy-l-phenylalanine (DOPA) moieties. Inspired by these marine adhesives, we developed a modular strategy to create symmetric triblock copolymers that feature well-defined density and placement of catechol groups. Tunable oxidation of the catechol end blocks into quinones and subsequent catechol-quinone crosslinking resulted in three-dimensional polymer network formation in water. The catechol content, which is controlled by the catechol block length, is shown to dictate the hydrogel curing times, shear strengths, and adhesive performance. We demonstrate the superiority of this strategy by creating adhesive hydrogels that exhibit superfast curing and significantly improved adhesive properties compared to conventional catechol-based hydrogels.