Synthesis of a magnetic crown ether ion imprinted polymer material for the selective adsorption of lithium

Abstract

To meet the requirements of the strong future market for lithium resources, it is crucial to retrieve lithium from high Mg/Li ratio brines. Herein, a novel magnetic crown ether Li⁺-imprinting polymer was designed by combining surface ion imprinting and magnetic separation techniques. Through the specific recognition of Li⁺ by the crown ether modified with a hydroxyl functional group, an excellent lithium ion separation performance was achieved. The separation selectivity factors for Li⁺ using OS@FeSi@CE-OH for Na⁺, K⁺ and Mg²⁺ were 7.74, 2.75 and 2.98, respectively. In addition, the use of an external magnetic field avoids filtration and centrifugation to achieve efficient recovery of adsorbed materials, which can shorten the analysis time and simplify the separation process. Therefore, these remarkable features address the problems encountered with traditional powder adsorbents, making OS@FeSi@CE-OH a potential candidate for lithium recovery.