Hydrogen-bonded polyamide 6/Zr-MOF mixed matrix membranes for efficient natural gas dehydration

New types of mixed matrix membranes (MMMs) were fabricated by incorporating Zr-MOF (UiO-66-NH2 and UiO-66-NH3+Cl-) filler into polyamide 6 (PA 6) polymer, enabling efficient natural gas dehydration. All membranes were characterized and applied for H2O/CH4 mixtures separation at 1 bar pressure difference at 30 °C. It was found that the Zr-MOF nanoparticles in a size range of 0.4–0.5 μm were successfully incorporated into the high permeability polymer PA 6 to obtain MMMs with 10–30 wt% particle loadings. MMMs loaded with 25 wt% of UiO-66-NH3+Cl- and 20 wt% of UiO-66-NH2 demonstrated ultrahigh H2O/CH4 selectivity of 747.7 and 687.4, respectively, and enhanced H2O permeability as well as H2O/CH4 selectivity compared with the pure PA 6 polymer. The excellent membrane performance attributed to direct and extensive hydrogen bonds between the polymer and MOFs. This type of MMMs could be an alternative for further research in H2O/CH4 separation at industrial scale.