Polystyrene Sulfonate Threaded through a Metal–Organic Framework Membrane for Fast and Selective Lithium‐Ion Separation. Issue 48 (2nd November 2016)

• Record Type: Journal Article
• Authors: Guo, Yi; Ying, Yulong; Mao, Yiyin; Peng, Xinsheng; Chen, Banglin
• Is Part Of: Angewandte Chemie international edition. Volume 55:Issue 48(2016)
• Page Start: 15120
• Page End: 15124
• Publication Date: 2016-11-02
• Subjects: lithium-ion separation -- membranes -- metal–organic framework membranes -- sulfonate networks -- transport properties; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201607329
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Extraction of lithium ions from salt‐lake brines is very important to produce lithium compounds. Herein, we report a new approach to construct polystyrene sulfonate (PSS) threaded HKUST‐1 metal–organic framework (MOF) membranes through an in situ confinement conversion process. The resulting membrane PSS@HKUST‐1‐6.7, with unique anchored three‐dimensional sulfonate networks, shows a very high Li + conductivity of 5.53×10 −4 S cm −1 at 25 °C, 1.89×10 −3 S cm −1 at 70 °C, and Li + flux of 6.75 mol m −2 h −1, which are five orders higher than that of the pristine HKUST‐1 membrane. Attributed to the different size sieving effects and the affinity differences of the Li +, Na +, K +, and Mg 2+ ions to the sulfonate groups, the PSS@HKUST‐1‐6.7 membrane exhibits ideal selectivities of 78, 99, and 10296 for Li + /Na +, Li + /K +, Li + /Mg 2+ and real binary ion selectivities of 35, 67, and 1815, respectively, the highest ever reported among ionic conductors and Li + extraction membranes. Abstract : Going separate‐Li : Intergrown and continuous HKUST‐1 membranes through which polystyrene sulfonate (PSS) has been threaded are constructed, giving rise to a three‐dimensional network of sulfonate groups. As a result of different binding affinities to sulfonate and size sieving effects, the membrane allows very fast and selective lithium‐ion transportation, and thus separation from other metal ions.