Nanoconfined Zeolitic Imidazolate Framework Membranes with Composite Layers of Nearly Zero Thickness

The key to preparing dense composite membranes is reducing the thickness of the composite layer with stable separation performance. Herein, we report a nanoconfined composite membrane prepared by in situ growth of Zeolitic Imidazolate Framework (ZIF) nanocrystals in the nanoporous layer of the substrate via a fine-tuning contra-diffusion method. The thickness of the composite layer on the membrane surface was nearly zero. The formed ZIF nanoconfined composite membranes showed state-of-art flux and high stability in removing dyes from water. This new strategy is expected to offer great opportunities for the potential practical application of polymer-supported metal-organic framework (MOF) composite membranes.