Study on graphene-oxide-based polyacrylamide composite hydrogels

In this paper, graphene oxide (GO) is added into poly(acrylamide) (PAM) hydrogels to modify their mechanical and thermal properties. The original PAM hydrogels, which are commonly crosslinked by N,N-methylenebisacrylamide (BIS), generally exhibit pronounced weakness and brittleness. After adding the GO into the hydrogel (BIS-gel), the GO–BIS-gels become very tough and exhibit fairly good tensile properties. The mechanical and thermal properties of GO–BIS-gels vary greatly by changing GO or BIS content. This phenomenon is probably caused by the microstructure, which related to the specific combination of GO sheets and BIS, acting as multifunctional crosslinking agents in the GO–BIS-gels. However, the BIS-gels have higher equilibrium swelling ratio than that of corresponding GO–BIS-gels. Contents of GO and BIS can be adjusted for preparing hydrogels with different applications.