Anhydrous interfacial polymerization of sub-1 Å sieving polyamide membrane
Guangjin Zhao, Haiqi Gao, Zhou Qu, Hongwei Fan, Hong Meng
Abstract
Abstract Highly permeable polyamide (PA) membrane capable of precise ionic sieving can be utilized for many energy-efficient chemical separations. To fulfill this target, it is crucial to innovate membrane-forming process to induce a narrow pore-size distribution. Herein, we report an anhydrous interfacial polymerization (AIP) at a solid-liquid interface where the amine layer sublimated is in direct contact with the alkane containing acyl chlorides. In such a heterophase interface, water-caused side reactions are eliminated, and the amines in compact arrangement enable an intensive and orderly IP reaction, leading to a unique PA layer with an ionic sieving accuracy of 0.5 Å. The AIP-PA membrane demonstrates excellent separation selectivities of monovalent and divalent cations such as Mg 2+ /Li + (78.3) and anions such as Cl - /SO 4 2- (29.2) together with a high water flux up to 13.6 L m −2 h −1 bar −1 . Our AIP strategy may provide inspirations for engineering high-precision PA membranes available in various advanced separations.