▎ 摘　　要

In this work, graphene is prepared by reduction of graphene oxide. The graphene obtained is used as the reinforcing nanofiller in an epoxy matrix. The incorporation of 0.1 wt.% loading of graphene in an epoxy matrix shows the maximum increase in the flexural properties as compared to the pure epoxy. It is due to good dispersion of graphene and interaction between C-N group of epoxy and C=O group of graphene. The loading of 0.1 of wt.% graphene in epoxy is used to prepare the glass fabric reinforced multiscale nanocomposites. This multiscale nanocomposite shows an enhancement in flexural properties. It is due to the mechanical interlocking associate with random dispersion of graphene in epoxy resin. In addition, glass fabric is coated with polyvinylpyrrolidone (PVP) modified multiwalled carbon nanotubes (MWNT) and its multiscale nanocomposites show the enhanced flexural strength. The increase in flexural strength is due to mechanical keying associated with the rough surface obtained with the coating of MWNT over glass fabric. Further, with an addition of 0.1 wt.% of graphene and MWNT coated glass fabric in epoxy multiscale nanocomposites, flexural properties enhancement are highest. It is due to the combined effect of mechanical keying and mechanical interlocking associated with graphene dispersion and rough surface of MWNT coat over glass fabric. In addition, the toughness of the MWNT coated glass fabric and graphene filled epoxy multiscale nanocomposites increases due to the mobile epoxy chains contributing towards the energy absorption. It is observed that the epoxy chains in contact with PVP coated MWNT are mobile as confirmed from dynamic mechanical analysis (DMA) studies. Thus, due to mechanical interlocking, the mobility of epoxy chains and mechanical keying; the flexural modulus, flexural strength, flexural toughness, and storage modulus obtained are highest for the graphene and MWNT coated glass fabric in epoxy multiscale nanocomposites.