Preparation mixed matrix membranes with different types of Al ₂ O ₃ -NOHMs for enhancing CO ₂ separation performance

Nano-organic hybrid materials (Al2O3-NOHMs) were synthesized with nano-alumina as the core, γ-(2,3-epoxypropyl) propyl trimethoxysiane (KH560) as the corona, and three of polyetheramine M2070, D2000, M1000 as the canopy, respectively. Al2O3-NOHMs were used as fillers to prepare MMMs with Pebax as substrate to improve the CO2 separation performance. The Al2O3-NOHMs were characterized by TEM and rheological properties. The results showed that the synthesized Al2O3-NOHMs were liquid-like and had a core-shell structure, which can effectively reduce Al2O3 agglomeration in the membrane. FT-IR analysis of MMMs showed that Al2O3-NOHMs and Pebax were physically blended, TGA indicated that Al2O3-NOHMs do not affect the thermal stability of the membrane, and XRD indicated that the addition of Al2O3-NOHMs destroyed the interchain hydrogen bond of Pebax and reduced the crystallinity of MMMs. The gas permeability of the membrane was tested under ideal gas conditions, compared with pure membrane, the CO2 permeability of Al2O3-NOHM(M2070)/Pebax MMMs and Al2O3-NOHM(D2000)/Pebax MMMs reached 137.15 Barrer (24.68%) and 147.52 Barrer (34.11%), and the selectivity of CO2/N2 reached 77.82 (58.84%) and 72.31 (47.59%) at 30°C and 0.3 MPa, respectively, surpassing 2008 Robeson upper bound.