Facile Synthesis of Dual-Layer Organic Solvent Nanofiltration (OSN) Hollow Fiber Membranes

A dual-layer organic solvent nanofiltration (OSN) hollow fiber membrane was prepared by a single-step coextrusion process with polybenzimidazole as the outer selective layer and hyperbranched polyethylenimine cross-linked polyimide as the inner support layer. The OSN membrane shows a rejection of >99% against methylene blue (MW: 319.85 g mol–1) with good solvent fluxes in water, methanol, and acetonitrile. The newly invented fabrication technology may provide simple, cost-effective, scalable, and high-performance OSN membranes for organic solvent recovery.