Fabrication And Separation Property Of Functional Graphene/Polyimide Hybrid Membrane

It is necessary that the collection and extraction of CO2 should be done, in order to meet the challenges of cliamte and environment. Oftenly, the extraction of CO2 will be adulterated with the gas with the similar quality. And the membrane separation will be taken to isolate this gas. In recent researches, organic-inorganic hybrid membranes are the most promising membranes for gas extraction. However, inorganic particles would have bad dispersity and small filling-volume when in membranes, so that the performance of membrances could not be enhanced very well. In this paper, isocynate and polyethylene glycol will be used in the modification of graphene oixde (GO), then the modified graphene oxide would be blended with polyimide membranes to produce a series of high permeable hybrid membrances for the use of the gas extraction of CO2.The structure, shape and thermal performance of the GO before and after the modification would be presented through FT-IR, TEM, Raman, TGA and XPS. The result was, both the dispersity and the thermal performance of the GO were improved after the modification through isocynate and polyethylene glycol. After being modified by using two different kind of isocynate (TDI, HMDI), TDI-GO showed a better dispersity. And the TDI-GO would had the best despersity when the TDI additive amount was 70%, while with the increase of the molecules of polyethylene glycol, the despersity of the modified GO would be meliorated.The functional graphene/(6FDA+ODA) hybrid membranes were produced in in-situ polymerization with the modified GO, and the structure, shape, surface charge quality and thermal performance of these membrances would be analyzied through TEM, Zeta, DSA and TGA. The result was, with the increase of isocyanate-GO, the despersity and thermal stability of IGO was improved in the membranes, while the Zeta electric potential value was raised. With the increase of IGO, its dispersion in the membrane gets better before it is poor. When the addition amount of IGO was 4.0 wt%, it’s the dispersion of membrane best. With the increase of the molecules of the polyethylene glycol, the desperisity of PEG-GO would be enhanced when the GO addtion volume remained 4.0 wt%. The test for the performance of gas extraction showed, with the increase of IGO, the permeability of CO2 and the selectivity of CO2/N2 was improved first then worsened, while with the increase of the molecules of PEG, the permeability of CO2 and the selectivity of CO2/N2 was improved when the PEG-GO addition volume remained the same. Beside, the functional graphene/PI hybrid membranes were produced in solution mixing, and they would be analyzied and the performance of gas extraction would be tested. The result was the permeability of CO2 and the selectivity of CO2/N2 was the best when IGO addition volume was 2.0 wt%, and turned worse when it was over 2.0 wt%. With the increase of the molecules of PEG, the permeability of CO2 and the selectivity of CO2/N2 were improved when the PEG addition volume remained the same.