▎ 摘　　要

In this study three polyimide-based flat sheet membranes were prepared, characterized and investigated regarding gas permeability properties. For the membranes' preparation Matrimid (R) 5218 was used as polymer matrix whereas graphene oxide (GO) was used as filler material. The thickness of the membranes ranged from 40 to 300 gm. The size of the GO material varied from 200 to 500 nm in length, according to the TEM images. Furthermore, the structural characteristics of the GO fillers were investigated by using N-2 adsorption at 77 K, X-ray diffraction (XRD), small angle X-ray scattering (SAXS), Raman spectroscopy and scanning electron microscopy (SEM). The three prepared membranes were also characterized by Fourier transform infrared spectroscopy (MIR), thermal gravimetric analysis (TGA) and gas permeability measurements at ambient temperature. The findings led to the possible explanation regarding the GO nanoflakes' anchoring which seems to be strongly dependent on the preparation method.