Abstract Polycrystalline ZIF-8 membranes of about 1 µm in thickness were successfully grown on α-alumina porous support by seeding-free aqueous synthesis. In order to achieve continuous well-intergrown membranes, a pseudo-surface of ZIF-8 was formed on the support by chemical modification. Our membrane preparation in aqueous system is based on the support-surface activation concept to control the surface density of nucleation sites. The grain size of polycrystalline membrane is directly related to a graft density of ligand-analogous surface modifier. Single-component gas permeation properties were investigated using H2, CO2, N2, CH4, C3H6, and C3H8. While the ideal permselectivities of H2 from CO2, N2, CH4, and C3H6 ever so slightly increased with the graft density, the ideal permselectivity of C3H6/C3H8 increased rapidly and reached 36 with corresponding C3H6 permeance of 8.5 × 10−8 mol/m2 s Pa. As a conclusion of the combined characterization with adsorption analysis, it was found that the sieving of C3H6/C3H8 by our seeding-free aqueous-synthesized ZIF-8 membrane is mainly governed by diffusion-driven separation process.

中文翻译：

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ZIF-8 MOF膜通过无晶种水合成的粒度控制及其在丙烯/丙烷分离中的性能

摘要 通过无晶种水相合成，在α-氧化铝多孔载体上成功生长了约1 µm 厚的多晶ZIF-8 膜。为了实现连续良好共生的膜，通过化学修饰在载体上形成了 ZIF-8 的假表面。我们在水性系统中的膜制备基于载体表面活化概念，以控制成核位点的表面密度。多晶膜的粒径与配体类似表面改性剂的接枝密度直接相关。使用 H2、CO2、N2、CH4、C3H6 和 C3H8 研究了单组分气体渗透特性。虽然来自 CO2、N2、CH4 和 C3H6 的 H2 的理想渗透选择性随着接枝密度的增加而略微增加，