Self‐Sealed Polyamide (PA)/Zinc Imidazole Framework (ZIF) Thin Film Nanocomposite (TFN) Nanofiltration Membranes with Nanoscale Turing Type Structures

Abstract

Abstract Polyamide (PA) thin‐film composite (TFC) nanofiltration (NF) membranes with superior water permeating nanoscale Turing type networks are formed using preloaded zinc(II) cations as diffusion slower during the interfacial polymerization on polysulfone support. Large nanopores in the size of about 4.3–8.0 Å formed during the interfacial polymerization process are self‐sealed by in situ grown zinc imidazole framework (ZIF) nanocrystals in a counterdiffusion polymerization reaction of Zn(II) cations with imidazole ligands. PA/ZIF mixed matrix NF membranes with superior water permeating networks are formed. Such novel membranes show not only 3–4 fold higher water flux than TFC membranes, but also retain comparably high salt rejection and antifouling resistance capability. The impact of Zn(II) loading levels, counterdiffusion reaction times, and structures of imidazole ligands on the structures and properties of formed TFN‐ZIF membranes are studied.