Interfacial assembling of flexible silica membranes with high chlorine resistance for dye separation

Abstract

Inorganic membranes have gained extensive attention due to their more uniform pore size, higher flux, and better chemical stability over traditional polymeric membranes. However, the development of inorganic membranes still faces substantial obstacles in the form of a difficult preparation procedure and the high cost of a large-scale synthesis. Herein, a facile interfacial assembly strategy is designed to prepare flexible silica membranes by the close and strong packing of ultra-small nanoparticles via crosslinking with trimesoyl chloride. Profiting from the extremely small size and tight packing of silica nanoparticles, the permeance of flexible silica membrane with a uniform pore size of 3.4 nm exceeds 210 L m−2 h−1 MPa−1, which is nearly 11 times higher than the polyamide membrane simultaneously ensuring the rejection effect. Meanwhile, the flexible silica membrane has no performance deterioration after exposure to 50000 ppm h of chlorine (NaOCl), indicating its excellent chlorine resistance. The facile interfacial assembly strategy applied for the synthesis of the membrane is highly reproducible and scalable (high-performance silica membrane with 100 cm2 has been obtained), which has overall flexibility after the curvature of 100 m−1, paving the way for the development of future applications.