Zhai Mengjiao, Moghadam Farhad, Gosiamemang Tsaone, Heng Jerry Y Y, Li Kang
Barrer Centre, Chemical Engineering Department, Imperial College London, London, UK.
Department of Chemical Engineering, Imperial College London, London, UK.
Nat Commun. 2024 Nov 26;15(1):10264. doi: 10.1038/s41467-024-54730-z.
Metal‒organic frameworks (MOFs) are nanoporous crystalline materials with enormous potential for further development into a new class of high-performance membranes. However, the preparation of defect-free and water-stable MOF membranes with high permselectivity and good structural integrity remains a challenge. Herein, we demonstrate a dual-source seeding (DS) approach to produce high-performance, water-stable MOF-303 membranes with hollow fiber (HF) geometry and preferentially tailored crystallographic orientation. By controlling the nucleation site density during secondary growth, MOF-303 membranes with a preferred crystallographic orientation (CPO) on the (011) plane were fabricated. The MOF-303 membrane with CPO on (011) provides straight one-dimensional permeation channels with a superior water flux of 18 kg m h in pervaporative water/ethanol separation, which is higher than that of most of the reported zeolite membranes and 1-2 orders of magnitude greater than that of previously reported MOF membranes. The straight water permeation channels also offer a promising water permeance of 15 L m h bar and a molecular weight cut-off (MWCO ≈ 269) for dye nanofiltration. These results provide a concept for developing ultrapermeable MOF membranes with good selectivity and structural integrity for pervaporation and nanofiltration.
金属有机框架材料（MOFs）是纳米多孔晶体材料，具有进一步发展成为新型高性能膜的巨大潜力。然而，制备具有高渗透选择性和良好结构完整性的无缺陷且水稳定的MOF膜仍然是一个挑战。在此，我们展示了一种双源晶种法（DS）来制备具有中空纤维（HF）几何形状且具有优先定制晶体取向的高性能、水稳定的MOF-303膜。通过控制二次生长过程中的成核位点密度，制备出了在（011）面上具有择优晶体取向（CPO）的MOF-303膜。在（011）面上具有CPO的MOF-303膜提供了直的一维渗透通道，在渗透汽化水/乙醇分离中具有18 kg m⁻² h⁻¹的优异水通量，高于大多数已报道的沸石膜，且比先前报道的MOF膜高1-2个数量级。直的水渗透通道在染料纳滤中还具有15 L m⁻² h⁻¹ bar的有前景的透水率和分子量截留值（MWCO≈269）。这些结果为开发具有良好选择性和结构完整性的用于渗透汽化和纳滤的超渗透MOF膜提供了一个概念。
