Influence of temperature on mixture adsorption in carbon nanotubes: a grand canonical Monte Carlo study

Grand canonical Monte Carlo simulations are used to examine the adsorption of a binary Lennard-Jones (σ22/σ11 = 1.426, ϵ22/ϵ11 = 1.059) gas mixture into a single-walled structured carbon nanotube. At a temperature, T∗=kT/ϵ11 = 1.2 (388.88 K) and above, the larger species with greater fluid–wall interaction is preferentially adsorbed. At lower temperatures selectivity shifts toward the smaller species, completely eliminating the larger species below T∗ = 0.935 (303 K). Axial pair correlation functions indicate that the smaller species condenses into the pore at lower temperatures.