Dynamic Disulfide Bond Regulated Tough Adhesion and On-Demand Debonding of the Albumin-Based Double Network Hydrogel to Diverse Substrates

The controllable tough adhesion of hydrogels and solid surfaces is essential for the development of soft-rigid hybrid medical devices. However, controllability is challenging for numerous tough adhesive hydrogels. Here, we develop a tough adhesion double network hydrogel based on bovine serum albumin and polyacrylamide (BSA/PAAm DN gel) with adjustable and robust adhesion toward diverse solid substrates because of the dynamic disulfide bonds (-S-S-). The albumin-based double network hydrogel simultaneously shows superior bulk toughness and interfacial toughness. To prepare the BSA/PAAm DN gel, the solid substrate is first modified with a silane coupling agent containing sulfhydryl, and then, the BSA/PAAm DN gel is in situ polymerized on the modified solid substrate. During the formation and destruction of disulfide bonds, the BSA/PAAm DN gel is attained between the surface of the hydrogel and modified solid substrates with reversible adhesion and on-demand debonding. The tough interfacial toughness of BSA/PAAm DN gel on diverse solid substrates exceeds 1000 J m(-2), and the adhesion energy even reaches 5000 J m(-2) for glass. This double network hydrogel based on the protein and polymer provides insights into the application of tough adhesion hydrogels for hybrid medical devices.