Novel anti-algal nanocomposite hydrogels based on thiol/acetyl thioester groups chelating with silver nanoparticles

Novel nanocomposite (NC) hydrogels based on thiol/acetyl thioester groups chelating with silver nanoparticles (AgNPs) were designed and prepared. The AgNPs acted as both cross-linkers to produce stable NC hydrogels and antimicrobials to prevent the algal adhesion on the surface of hydrogels. The amount of AgNPs embedded in the NC hydrogels had a great influence on the mechanical properties of the NC hydrogels. When the feed molar ratio of the silver element to the sulfur element (Ag/S) approached 0.9, the hydrogels showed the highest mechanical properties. The dynamic nature of the interactions between the AgNPs and thiol/acetyl thioester groups endowed these NC hydrogels with interesting rapid mechanical recovery properties. The NC hydrogels containing thiol groups showed better self-recovery performance than the hydrogels with acetyl thioester groups. In addition, the NC hydrogels with AgNPs exhibited good anti-algal performance for Phaeodactylum tricornutum and Chlorella. When the Ag/S ratio exceeded 0.9, there were almost no algae on the surface of the NC hydrogels. Consequently, these hybrid hydrogels have promising applications in marine antifouling coating and the interfaces of biomaterials.