In-situ construction of zinc-gel-ZIFs MMMs within metal gel towards enhanced gas separation

Metal-organic frameworks (MOFs), with the characteristics of intrinsic pore channels and adjustable pore structure, are deemed as potential membrane materials. Most researches aimed at constructing MOFs-based mixed-matrix membranes (MMMs) within polymer as the matrix. Herein, we proposed the in-situ construction of a zinc-gel-ZIFs MMMs within a zinc-gel matrix, which shows the following features. First, the metal gel, with a high-density metal source, participates the coordination reactions, which induces the oriented growth of MOFs as independent gas transport channels; Second, the gel network, similar to polymers, not only maintain the structural densification but also enhance the interfacial compatibility during in-situ growth process. A 3-fold increase in the Young's modulus compared with polymer matrix counterparts explains the excellent bending resistance and high-pressure separation ability; Third, the stable solvent and residual metal gels in the gel network can further facilitate the gas adsorption, and the optimal zinc-gel-ZIFs MMMs shows competitive CO 2 /N 2 and CH 4 /N 2 separation performance compared with state-of-the-art membranes.