Effect of graphene oxide content on morphology and topography of polysulfone-based mixed matrix membrane for permeability and selectivity of carbon dioxide and methane

摘要

In this work, mixed matrix membranes based on polysulfone containing different contents of graphene oxide were prepared using a phase inversion process. The morphological, and structural properties as well as surface features of the samples were investigated by means of field-emission scanning electron microscopy, infrared and x-ray diffraction spectroscopies, as well as atomic force microscopy. The gas permeation/selectivity behavior of graphene oxide-loaded polysulfone samples was studied using pure carbon dioxide, and methane. Morphological images depicted that the addition of graphene oxide to polysulfone in the presence of isopropyl alcohol as non-solvent was reduced the numbers of finger-like macro-voids, and caused to the formation of teardrop-like structures. Besides the x-ray patterns and Fourier transform infrared spectra confirmed the graphene oxide nano-plates and polysulfone with no chemical interactions, the atomic force microscopic patterns demonstrated a decrease in the average roughness of samples' surface from 21.85 nm for plain polysulfone membrane to 5.02 nm for ones containing 2 weight percentages of graphene oxide as the optimum sample. Finally, a significant enhancement for the selectivity of carbon dioxide/methane with the value of 38.08 has been observed by the sample which was approximately 22-fold more than that of plain polysulfone.