Enhanced compatibility and selectivity in mixed matrix membranes for propylene/propane separation

Abstract

Mixed matrix membranes (MMMs) based on metal-organic framework (MOF) have great promising application in separation of gas mixtures. However, achieving a good interfacial compatibility between polymer and MOF is not straightforward. In this work, focusing on one of the most challenging olefin/paraffin separations: propylene/ propane (C 3 H 6 /C 3 H 8 ), we demonstrate that modification of the MOF filler via dopamine polymerization using a double solvent approach strongly improves interfacial compatibility. The resulting membranes show an outstanding separation performance and long-term stability with propylene permeability nearly 90 Barrer and propylene/ propane selectivity close to 75. We anticipate that similar MOF modification strategies may help solve the problem of interface defects in the manufacture of MMMs and be extended to other porous fillers.

Recent Progress and Challenges in the Field of Metal–Organic Framework-Based Membranes for Gas Separation

“…Furthermore, doping 2-aminobenzimidazole (ambz) [116] and ionic liquid (IL)/Ag + [109] into ZIF-8 could improve the membrane performance. ZIF-8 is mostly employed as a leading polycrystalline membrane candidate for C 3 H 6 /C 3 H 8 separation, and few membranes other than ZIF-8 have been reported so far (Table 5) [93,97,100,102,103,109,[117][118][119][120][121][122][123][124][125], while MOFs other than ZIF-8 have been used as fillers for MMMs (Table 6) [126][127][128][129][130][131][132][133][134][135]. It is important to explore the possibilities of other MOFs and optimize the interaction between the MOF filler and the polymer matrix with the help of computational simulations.…”

Engineering Metal-Organic-Framework (MOF)-Based Membranes for Gas and Liquid Separation

“…Herein, a large number of methods have been developed to enhance interfacial compatibility, including chemical modification, regulation, and control of MOF topological structures, OMS coordination, derivative interaction, hydrogen bonding, and secondary interfacial polymerization. For example, He et al [ 67 ] adjusted the MOF aperture through the double solvent approach by dopamine polymerization of [Ni 8 (L) 6 ]n (Ni-MOF). Due to the hydrogen bonds formed between RNH 2 /R 2 NH groups in polydopamine and R 3 N groups on polymer, the interfacial compatibility between MOF and 6FDA-DAM polymer matrix was enhanced, reducing the interface defects of Ni-MOF/PDA/6FDA-DAM MMMs.…”

Enhanced CO2/N2 separation in hybrid composite membrane via dispersion of hollow defect‐engineered Zr‐MOF nanoparticles

“…15,16 By combining enhanced diffusivity of CO 2 through the filler with the excellent processability of polymers, mixed-matrix membranes (MMMs) have been proven to be promising for mitigating the above dilemma. 17,18 Among them, metal-organic framework (MOF) has been widely conceived as a competent filler due to its exceptional tunability in topology, porosity, and functionality. [19][20][21] A wide variety of MOFbased MMMs have shown enhanced CO 2 separation performances in comparison with neat polymer membranes.…”