The role of graphene oxide in dramatically enhancing the mechanical and photoresponsive self-healing properties of poly(N, N-dimethylacrylamide) hybrid hydrogels

A fast self-healing hydrogel system with high strength and excellent response to the near infrared light (NIR) was proposed. The effect of graphene oxide (GO) on the mechanical and self-healing properties of poly(N,N-Dimethylacrylamide) (PDMA) hydrogels was studied. The results indicated that the self-healing efficiency of pure PDMA hydrogels was lower than that of PDMA-GO hydrogels. Especially, when the content of GO was more than or equal to 3 mg ml−1, the self-healing efficiency can reach to approximately 100% after 2 h. It is due to that the increase in the content of GO could induce a rapid temperature rise of the hydrogel, which was benefit for improving the fast self-healing capacity. Most notably, PDMA-GO hydrogels still exhibited the excellent mechanical properties and the stable loading-unload behavior after the damage parts were healed. It can be contributed that GO forms hydrogen bonds with the three-dimensional network structure of the hydrogel matrix.