Janus graphene oxide nanosheets prepared via Pickering emulsion template

Janus graphene oxide (GO) nanosheets functionalized by amino-containing chemicals were prepared via Pickering emulsion template. A wax-in-water Pickering emulsion was used to mask one side of GO nanosheets in order to achieve asymmetric chemical functionalization. Janus particles were obtained by removing the oil phase. The successful reaction of epoxy groups on the surface of GO with amino-containing chemicals was confirmed by Fourier transform infrared spectroscopy (FT-IR) and thermal gravimetric analysis (TGA). The asymmetric surface structure of Janus GO nanosheets was detected by atomic force microscope (AFM) and X-ray diffraction (XRD). The efficient stabilization of an oil-in-water Pickering emulsion by Janus GO was proved. Polymer microspheres fabricated by using Janus GO as Pickering stabilizer had a more hydrophilic surface compared with those stabilized by symmetrically modified GO.