Influence of nanopore density on ethylene/acetylene separation by monolayer graphene

The use of nanoporous graphene for separation has attracted increasing interest over the past few years. Nanopore size, temperature, pressure and functionalization are vital for selectivity, but the influence of nanopore density is not known. Thus, we designed a monolayer nanoporous graphene membrane and revealed the influence of nanopore density on its ethylene/acetylene separation performance by employing molecular dynamics (MD) simulations. Our results indicate that an optimal nanopore density exists for permeation flux and selectivity. The MD simulation results were confirmed by density functional theory (DFT) and the kinetic theory of gases. The interactions between ethylene/acetylene and nanopores were also investigated, and van der Waals (vdW) interactions with slight steric repulsion were detected.