Facilitate Gas Transport through Metal-Organic Polyhedra Constructed Porous Liquid Membrane

Type II porous liquids are demonstrated to be promise porous materials. However, the category of porous hosts is very limited. Here, a porous host metal-organic polyhedra (MOP-18) is reported to construct type II porous liquids. MOP-18 is dissolved into 15-crown-5 as an individual cage (5 nm). Both the molecular dynamics simulations and experimental gravimetric CO₂ solubility test indicate that the inner cavity of MOP-18 in porous liquids is unoccupied by 15-crown-5 and is accessible to CO₂ . Thus, the prepared porous liquids show enhanced gas solubility. Furthermore, the prepared porous liquid is encapsulated into graphene oxide (GO) nanoslits to form a GO-supported porous liquid membrane (GO-SPLM). Owing to the empty cavity of MOP-18 unit cages in porous liquids that reduces the gas diffusion barrier, GO-SPLM significantly enhances the permeability of gas.