Constructing solubility-diffusion domain in pebax by hybrid-phase MOFs for efficient separation of carbon dioxide and methane

A MIL-88B-on-UIO-66 (Abbreviation for UIO@MIL) hybrid-phase MOFs with rod-to-octahedral structure was obtained by the epitaxial growth method, and was added to Pebax matrix to develop a series of Pebax/UIO@MIL MMMs for CO 2 /CH 4 separation. In UIO@MIL hybrid-phase MOF, CO 2 solubility domain is formed in the core of UIO@MIL due to the abundant Zr–OH on the surface of UIO-66. MIL-88B has large pores and special rod-like structure that can entangled with the Pebax chain and adjust the spacing of the Pebax chain to form CO 2 diffusion domains in MMMs. The results show that Pebax/UIO@MIL-4 membrane has the best CO 2 separation performance, the CO 2 permeability is 379.07 ± 10.00Barrer, and the CO 2 /CH 4 selectivity is 38.1 ± 1.33. Therefore, hybrid-phase MOFs fillers provide a novel idea for the design of excellent MMMs.