• composites;
  • membranes;
  • separation techniques


Pebax-1657 is known as a promising polymeric membrane material for CO2/N2 and CO2/H2 separation. In order to further improve its gas separation performance and reinforce the membrane, different fillers including silica nanoparticles, polystyrene (PS) colloids, and carbon nanotubes (CNTs) were incorporated into the polymer matrix to form nanocomposite membranes. The nanocomposite membranes of Pebax-1657/silica and Pebax-1657/PS colloid had a decreased CO2 permeability and selectivity over N2 or H2 compared to the pure Pebax-1657 membrane, while the Pebax-1657/CNT nanocomposite membranes had an increased CO2 permeability, retaining similar CO2/N2 or CO2/H2 selectivity compared to the pure polymer membrane. The CO2 permeability increased with increasing CNT content and reached a maximum at 5 wt % CNTs. The CNT-enhanced gas permeability was attributed to the increase in gas diffusivity. The tensile modulus of Pebax-1657 increased 43% after adding 5 wt % single-wall CNTs (SWNTs), and increased 24% after adding 5 wt % multi-wall CNTs (MWNTs). Thus, it is feasible to add CNTs to Pebax-1657 membranes for improved mechanical strength and gas separation performance. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2867–2876, 2013