Preparation and Gas Separation Performance of Polysulfone Mixed Matrix Membrane

As an economical, environmentally friendly, and highly efficient separation technology, membrane separation is a popular research topic in the field of separation. Organic polymer materials have attracted considerable attention in membrane separation because of their controllable preparation processes, simple modification method, and high toughness. Taking polysulfone (PSF) as the substrate of gas separation membrane, we prepared the mixed matrix membrane jointly by using the solution casting method and by adding graphene oxide (GO) and carbon nanotubes (CNTs). On this basis, the permeability of the membrane for CO2 and N2 and the permeability coefficient of the mixed gas were studied. With the addition of CNTs and GO, the permeability of gas was significantly improved. At 0.2 MPa, permeability of CO2 increased from 553 Barrer to 975 Barrer, and permeability of N2 increased from 536 Barrer to 745 Barrer. The max ideal separation coefficient of CO2 and N2 is 1.94 at 0.1 MPa. Increasing of the content of carbon nanotubes can significantly improve the permeability coefficient of CO2, while the change of inlet side pressure has a great impact on the permeability coefficient of N2. At 0.1 MPa, when the ratio of CNTs to GO was 5 : 1, the ideal permeability coefficient of CO2/N2 was 1.94, whereas the ideal permeability coefficient of PSF membrane was 1.46. The above results of PSF/GO/CNT mixed matrix membrane lay a theoretical foundation for industrial application.