Investigation of poly(ether-b-amide)/nanosilica membranes for CO2/CH4 separation

The results of molecular dynamics (MD) simulations on transport process of CO₂ and CH₄ gases in poly(ether-b-amide) (PEBAX)/nanosilica membranes are discussed. The diffusion coefficients for CH₄ and CO₂ gases at 6 cases with different amounts of nanosilica loading in the simulation boxes are presented. The results show that diffusion coefficients for CO₂ gas in all cases are larger than those for the CH₄ one. Moreover 10% nanosilica loading case shows maximum effects on diffusion coefficients and improves them by more than 68% and 157% for CO₂ and CH₄ gases, respectively. Additionally, the results of 3-D Cartesian trajectories and displacements curves are presented and the jumping attempt of CO₂ is significantly more than that of CH₄. Due to the rubbery state of PEBAX membranes in ambient temperature, the results confirm that channel lifetimes are very short and then back diffusion is not observed for this polymer.