“…3, CO 2 will pass through the polymer layer based on both solution diffusion and carrier-mediated diffusion, while other gases, such as nitrogen (N 2 ), O 2 , CH 4 , and H 2 , can only pass through via a solution-diffusion mechanism. A thin selective polymer layer, high diffusion coefficient, and steep gradient of carrier concentrations across the polymer will positively affect the CO 2 permeate flux, while low solubilities and diffusion coefficients for other gases in the polymer will lead to high selectivity for For such facilitated transport membranes, poly(amidoamine), poly(vinyl alcohol) (PVA), polyallylamine (PAA), and polyvinyl amine (PVAm) are often applied as selective layers with/without amine additives [48,83].…”