In this study, graphene oxide (GO), polyethylenimine-graphene oxide (PEI-GO), and polyethylenimine-graphene oxide@zeolite imidazolate framework-8 (PEI-GO@ZIF-8) were added to poly (ether-block-imide) 2533 (PEBAX 2533) by content and mixed to be used a...
In this study, graphene oxide (GO), polyethylenimine-graphene oxide (PEI-GO), and polyethylenimine-graphene oxide@zeolite imidazolate framework-8 (PEI-GO@ZIF-8) were added to poly (ether-block-imide) 2533 (PEBAX 2533) by content and mixed to be used as mixed matrix membranes (MMMs). The MMMs penetrated single CO2 and N2 gas, to investigate the performance of each filler and content.
Through Fourier-transform infrared spectrometer (FT-IR) and powder X-ray diffractometer (XRD), it confirmed GO, PEI-GO, and PEI-GO@ZIF-8 were synthesized well, and changes in crystallinity of the materials were confirmed due to modification. When MMMs, FT-IR peak change was not observed, because the small amount of the filler. As a result of analysis through Thermogravimetric Analyzer (TGA), it was confirmed that the thermal stability of the filler increased as GO was modified to PEI and ZIF-8. The thermal stability of the MMMs was also increased with the content of the filler, and it was confirmed that the PEBAX/PEI-GO@ZIF-8 MMMs had the best thermal stability.
In Gas permeation, case of the PEBAX/GO MMMs, the permeability of both N2 and CO2 gas tended to decrease as the GO content increased. On the other hand, the CO2/N2 selectivity steadily increased to 58.89 which was the highest at 0.3 wt%, decreased at 0.5 wt% to 55.34 which was similar to 0.1 wt%, and the overall selectivity was improved overall compared to the pure PEBAX 2533 membrane.
In the PEBAX/PEI-GO MMMs, the N2 permeability decreased steadily. The CO2 permeability decreases from 0.1wt% and then increases from 0.3wt%, and decreases slightly from 0.5wt%, but shows a value similar to 0.3wt%. The CO2/N2 selectivity steadily increased to 73.5, the highest at 0.3wt%, and slightly decreased at 0.5wt%.
The N2 permeability of the PEBAX/PEI-GO@ZIF-8 MMMs shows a decreasing trend. The CO2 permeability was from 0.1wt% to 221.88 Barrer, showing the highest permeability in all MMMs. It was confirmed that the CO2 permeability gradually decreased at the above content. Unlike the PEBAX/GO and PEBAX/PEI-GO MMMs, the CO2/N2 selectivity recorded the highest 60 at a content of 0.1wt%, and then decreased.
When the MMMs subjected to gas permeation were illustrated in upper bound (2008), it was confirmed that all membranes were close to the upper bound compared to the pure PEBAX 2533 membrane. Among them, PEBAX/PEI-GO of 0.3wt% and 0.5wt% showed excellent performance beyond the upper bound.