Bao Shiwen,Ma Zhaoyu,Yu Lei,Li Qi,Xia Jiaxiang,Song Song,Sui Kunyan,Zhao Yongye,Liu Xueli,Gao Jun
Certain biological channels exhibit remarkable selectivity, effectively distinguishing between competing cations. If artificial membranes could achieve similar precision in differentiating competing ions from Li + , it could advance sustainable technologies in lithium extraction. In this study, we present a covalent organic framework (COF) membrane featuring a randomly oriented structure that enables selective separation of major competing ions from Li + . The random orientation results in narrow pores, which impart size-based selectivity among alkaline ions. Additionally, the COF incorporates sulfonic groups that preferentially bind to Na + and K + , facilitating their transport while retaining Li + . These synergistic mechanisms endow the membrane with a selectivity beyond detection limit for K + and Na + over Li + . When driven by an electrical potential, the ion flux through the membrane is enhanced by over an order of magnitude. Notably, the membrane also permits the transport of Mg 2+ and Ca 2+ while still rejecting Li + , leveraging differences in their ion mobility. This work should advance the design and construction of biomimetic materials for the extraction of valuable species from seawater and other aqueous sources.
Electrospinning technique can be used to produce the three-dimensional nanofibrous scaffold similar to natural extracellular matrix, which satisfies particular requirements of tissue engineering scaffold. Randomly-oriented and aligned poly(lactic-co-glycolic acid) (PLGA) and PLGA/gelatin biocomposite scaffolds were successfully produced by electrospinning in the present study. The resulting nanofibrous scaffolds exhibited smooth surface and high porous structure. Blending PLGA with gelatin enhanced the hydrophilicity but decreased the average fiber diameter and the mechanical properties of the scaffolds under the same electrospinning condition. The cell culture results showed that the elongation of the osteoblast on the aligned nanofibrous scaffold was parallel to the fiber arrangement and the cell number was similar to that of randomly-oriented scaffold, indicating that the aligned nanofibrous scaffold provide a beneficial approach for the bone regeneration.
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