A General Route to Robust Nacre-Like Graphene Oxide Films.

Artificial nacre-like composite films of graphene oxide (GO) with a variety of commercially available water-soluble polymers were fabricated by a gel-film transformation (GFT) technique. The blending of a polymer into the aqueous dispersion of GO can modulate the interaction between GO sheets. Typically, the attraction force between polymer and GO sheets overcomes the dominant hydration and electrostatic repulsive forces between GO sheets, promoting the gelation of GO. Cast drying the resultant GO hydrogel containing small amounts of polymer (1-20 wt % relative to GO depending on the intrinsic structures of polymers) generates layered GO composite films with tensile strengths over 200 MPa and failure strains larger than 3.0%, which are higher than those of natural nacre and most nacre-like GO films. These results indicate that GO/polymer composite hydrogels are excellent precursors for nacre-like GO films and that the GFT approach is a general route toward the large-scale fabrication of nacre-like GO films with unique combinations of high strength and high toughness.