▎ 摘　　要

Nacre-like graphene nanosheets (GNS) obtained from the L-glutathione mediated reduction of graphene oxide (GO) were used to develop epoxy composites. Field emission scanning electron microscopy (FE-SEM) revealed the layer-by-layer nacre-like structure of GNS. Fourier transform infrared spectra (FT-IR), X-ray diffraction (xRD), Raman spectroscopy, and thermogravimetric analysis (TGA) measurements confirmed the successful reduction of GO. The oxidized product of L-glutathione is expected to perform as capping agent to stabilize the GNS, and also stitches the graphene sheets through hydrogen bonding. Transmission electron microscopy was used to confirm the dispersion of GNS in the epoxy matrix. The GNS/epoxy composites showed significant improvement of-91% in fracture toughness (Kic), 46% in flexural strength, and 71% in flexural modulus at 0.25 wt% GNS loadings. The probable toughening mechanism was elucidated from fracture FE-SEM images. The improved compatibility and strong interfacial interaction were reflected in the enhanced storage modulus value. The thermal stability of the composites as investigated by TGA showed appreciable improvement in the degradation temperature.