Synthesis of a PEBAX-1074/ZnO nanocomposite membrane with improved CO2 separation performance

Abstract

In this investigation, polymeric nanocomposite membranes (PNMs) were prepared via incorporating zinc oxide (ZnO) into poly (ether-block-amide) (PEBAX-1074) polymer matrix with different loadings. The neat membrane and nanocomposite membranes were prepared via solution casting and solution blending methods, respectively. The fabricated membranes were characterized by field emission scanning electron microscopy (FESEM) to survey cross-sectional morphologies and thermal gravimetric analysis (TGA) to study thermal stability. Fourier transform infrared (FT-IR) and X-ray diffraction (XRD) analyses were also employed to identify variations of the chemical bonds and crystal structure of the membranes, respectively. Permeation of pure gases, CO2, CH4 and N2 through the prepared neat and nanocomposite membranes was studied at pressures of 3–18bar and temperature of 25°C. The obtained results showed that the fabricated nanocomposite membranes exhibit better separation performance compared to the neat PEBAX membrane in terms of both permeability and selectivity. As an example, at temperature of 25°C and pressure of 3bar, CO2 permeability, ideal CO2/CH4 and CO2/N2 selectivity values for the neat PEBAX membrane are 110.67 Barrer, 11.09 and 50.08, respectively, while those values are 152.27 Barrer, 13.52 and 62.15 for PEBAX/ZnO nanocomposite membrane containing 8wt% ZnO.