Abstract Clay nano-platelets (NC) and Graphene oxide nanosheets (GO) are functionalized by the aid of 1,4- butanediol diglycidyl ether (BDDE) through an aminosilane coupling agent, i.e. 3-Triethoxysilyl propylamine (APTES). The products obtained from the modification process are characterized by visual assessment, FTIR, XRD, TGA, UV–vis, AFM and FE-SEM analyses. The results clearly demonstrate the epoxide ring of BDDE is chemically attached on the surface of the fillers. Furthermore, the process is causing the stacks of layers expand and d-spacing increases. The functionalized NC and GO, i.e. MNC and MGO, are then impregnated into an undiluted clear di-functional bisphenol A/epichlorohydrin derived liquid epoxy resin at 0.3% weight concentration by simple mechanical mixing. The films are also morphologically studied by FE-SEM. Dynamic and static mechanical properties are investigated by DMA and tensile testing. The outcomes demonstrate that there exists an optimum mixing ratio of MGO and MNC to obtain the best mechanical properties, i.e. MGN (70:30). Besides, almost all the modified samples show improved mechanical properties compared to their unmodified counterparts.