In this study, a thermoplastic polyurethane (TPU) tree-like nanofiber membrane was fabricated via one-step electrospinning by adding a small amount of tetrabutylammonium chloride (TBAC). On the basis of the "push and pull" effect, double-layer membranes composed of pure TPU nanofiber membranes (hydrophobic) and TPU/TBAC tree-like nanofiber membranes (hydrophilic) were prepared by the direct electrospinning compounding method. The double-layer membranes were used as waterproof breathable materials with moisture unidirectional transport properties and good shielding properties. The water resistance, mechanical, waterproof, moisture permeability, air permeability, air filtration and moisture unidirectional transport performances of the double-layer membranes were tested. The results showed that the double-layer TPU membranes displayed good performances compared with the existing products on the market; they provide a new approach for the development of waterproof breathable materials.

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Practical, ultrathin metal‐organic framework (MOF) membranes have the potential to achieve otherwise difficult separations, but current fabrication methods still face challenges in the simultaneous improvement of both selectivity and permeance. Here, ultrathin, low‐crystallinity‐state MOF (LC‐MOF) membranes are realized by a facile general method of interface layer polarization induction. This is achieved using an interface layer having metal ions with dense and uniform distribution, resulting in the creation of abundant open metal sites. Three types of LC‐MOF membranes (45–150 nm) are fabricated, among which ZIF‐8 membranes modified in situ with diethanolamine (DZIF‐8) display the best performance for propylene/propane separation, showing unprecedented propylene permeance (2000–3000 Gas Permeance Units) with very high propylene/propane selectivity (90–120).

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