Functionalisation of MUF-15 enhances CO₂/CH₄ selectivity in mixed-matrix membranes

MUF-15 (MUF = Massey University Framework) is a metal-organic framework with pores that can be tuned by ligand functionalisation. Crystallites of MUF-15 and derivatives were blended with the organic polymer 6FDA-DAM to produce mixed-matrix membranes (MMMs). At a loading of 30 wt%, membranes with MUF-15-F, MUF-15 with an appended fluoro group, exhibited a CO₂ permeability of 1300 Barrer and CO₂/CH₄ selectivity of 37.1. These values surpass membranes with the parent MUF-15 and exceed the Robeson upper bound.