Pebax/MWCNTS-NH₂ Mixed Matrix Membrane And Its CO₂/N₂ Separation Performance

Mixed Matrix Membranes（MMMs）plays a promising role in the separation of flue gases.The trade-off between permeability and selectivity in membrane separation is a challenge until now.Rational design of inorganic filler,compatibility of filler with the polymer and dispersion of filler into polymer plays an important role in deciding the morphology and separation by a membrane.Herein we explored different methods while using different solvents to maximize dispersion of filler to produce defect-free flat sheet mixed matrix membranes.Cross-sectional scanning electron microscopy analysis of the membranes was performed to investigate the morphology of the prepared membranes.X-ray diffraction and Fourier transform infrared analysis were also carried out to characterize the membranes.Permeation tests for CO₂/N₂ gas pair were performed at ambient and sub-ambient temperatures to study the effects of the solvents on the permeation properties of the membranes.The solvent properties,such as the molar volume,boiling point,and solubility parameters,were investigated as were the membranes characteristics,such as the crystallinity,d-spacing,and fractional free volume.The result obtained from the experimental analysis showed that membrane fabricated with higher molar volume solvent were more efficient as compared to others.Considering the trade-off between different parameters（molar volume of solvent,fraction-free volume,crystallinity of membranes）the permeability and selectivity of Pebax/MWCNTs-NH₂ MMMs was optimized to 405 Barrer and 51 respectively.Furthermore,the membrane permeation was checked at sub ambient conditions and it was found that as we lower the permeation temperature the CO₂/N₂ selectivity increased up to 80.