Preparation And Property Of Nacre-inspired Hierarchical Nanocomposites Based On Graphene Oxide

In recent years,graphene oxide(GO)has become one of the ideal reinforcements for the construction of nacre-like composites due to its light weight,excellent mechanical properties,excellent solution dispersion and so on.In this paper,the topic is based on the design concepts that the interface interaction can be improved by the H bonding between various oxygen functional groups on the surface of GO and polymer matrix.In the strategy of bottom-up assembly,GO lamellar structure unit and polymer were mixed and filtered to obtain GO-based artificial nacre nanocomposites.(1)GO and sodium alginate(SA)artificial nacre nanocomposites were prepared by vacuum filtration.Nanocomposites with stronger mechanical properties were fabricated by optimizing the GO and SA concentration ratio.Infrared spectroscopy(FTIR),X ray diffraction(XRD)and X ray photoelectron spectroscopy(XPS)showed that with the incorporation of SA into GO layers the film cross-section SEM image has changed.The results of cross-section scanning electron microscopy(SEM)image showed that the film had the“brick-and-motar” hierarchical nacre structure.The formation of this unique layered structure significantly improves the mechanical properties of graphene oxide based films.In addition,H bonding between the GO and the SA has a certain synergistic toughening effect.Finally,GO-SA nanocomposites were chemically reduced by hydroiodic acid(HI),and rGO-SA nacre-mimicking materials were obtained.It was found that the film after reduction has certain hydrophobias and conductivity.(2)Similarly,GO and polyacrylic acid(PAA)composite were prepared by vacuum filtration.By optimizing the concentration ratio of GO to PAA,the composite films with higher mechanical properties were prepared.This kind of thin film has obvious "brick-mortar" nacre-like layer structure.In addition,H bonding between the GO and the PAA also has a certain synergistic tougheningeffect.HI was used to reduce the film.The results show that the reduced film not only has a great improvement in mechanical properties,but also has certain hydrophobias and conductivity.In summary,two kinds of polymer and GO were selected to form the graphene-based artificial nacre nanocomposites by the interaction of H bond at the interface which produce a certain degree of synergistic toughening.The effects of natural biomaterials and synthetic polymers on mechanical properties of GO-based artificial nacre nanocomposites were studied.This material is promising for applications in aerospace,flexible supercapacitor electrodes,artificial muscle and tissue engineering.