Dynamic Au-Thiolate Interaction Induced Rapid Self-Healing Nanocomposite Hydrogels with Remarkable Mechanical Behaviors

Synthetic materials capable of self-healing when damaged have attracted increasing attention and have been developing rapidly because of their many potential applications. Despite great achievements, there is an urgent need to advance the mechanical properties and reduce the time for healing simultaneously because of limited branch functionality and poor polymer mobility. Here, we report robust and smart hydrogels prepared using multi-vinyl-modified gold nanoparticles through a thiolate-gold coordination interaction as large crosslinkers. As a result of efficient energy dissipation from dynamic gold crosslinks with enhanced branching, hydrogels exhibit excellent elasticity with increased mechanical strength at high elongation, even when notched. Combined with thiolate-gold interaction as a healing motif and a notable optothermal effect of nanoparticles, hydrogels deliver rapid self-healing with optimal efficiency of nearly 96% under near-infrared irradiation in 1 min. These properties may shed light on promising applications for this kind of hydrogel in biomedicine and engineering.