Electrospun, crown ether functionalized PS-b-PMAA block copolymer fibers for Li extraction from aqueous media

Crown ether-functionalized polystyrene- block -poly(methacrylic acid) copolymers form lithium (Li) complexes with ML or ML₂ stoichiometry. The extraction efficiency can be tuned by the choice of crown ether; benzo-9-crown-3, 12-crown-4, and benzo-12-crown-4 were evaluated. To enhance Li uptake in the solid material, electrospun fibers with a high surface-to-volume ratio were fabricated. Li selectivity over sodium and overall uptake performance were assessed via solid–liquid extraction. A material based on benzo-12-crown-4 demonstrated the highest Li capacity (up to 1.9·10 −4 ± 2.4·10 −5 mmol Li/g polymer) and excellent selectivity, enabling efficient extraction without the need for organic solvents. • PS -b- PMAA-Crown ether fibers form Li + complexes in aqueous media. • Extraction tuned via crown ether: Benzo-9-Crown-3, 12-Crown-4, Benzo-12-Crown-4. • None of studied materials shows uptake of Na + . • Benzo-12-Crown-4-based material shows highest Li + capacity. • Solid–liquid extraction shows high selectivity Li + vs. Na + .