Ultratough and ultrastrong graphene oxide hybrid films via a polycationitrile approach

Graphene oxide (GO) is a classic two dimensional (2D) building block that can be used to develop high-performance materials for numerous applications, particularly in the energy and environmental fields. Currently, the precise assembly of GO nanosheets into macroscopic nanohybrids of superior strength and toughness is desirable, and faces challenges and trade-offs. Herein, we exploited the freshly established polycationitrile method as a powerful molecular crosslinking strategy to engineer ultratough and ultrastrong GO/polymer hybrid films, in which a covalent triazine-based network was constructed in a mild condition to reinforce the interface between GO nanosheets. The tensile strength and toughness reached 585 ± 25 MPa and 14.93 ± 1.09 MJ m^-3, respectively, which, to the best of our knowledge, are the current world records in all GO-based hybrid films. As an added merit of the tailor-made polymer crosslinker, the high mechanical performance can be maintained in large part at an extremely high relative humidity of 98%. This emerging interface-engineering approach paves a new avenue to produce integrated strong-and-tough 2D nanohybrid materials that are useful in aerospace, artificial muscle, energy harvesting, tissue engineering and more.