Novel thin‐film nanocomposite membrane with water‐soluble polyhydroxylated fullerene for the separation of Mg2+/Li+ aqueous solution

Despite the prosperity of membrane technology, the separation efficiency for Mg2+/Li+ mixture is still far from satisfactory. Herein, a novel thin‐film nanocomposite (TFN) membrane was developed by loading polyhydroxylated fullerene (PHF) via interfacial polymerization. The effects of the PHF dosages on the as‐developed membranes were investigated comprehensively by XPS, SEM, AFM, contact angle measurements, as well as nanofiltration tests. The results revealed the TFN membrane containing 0.01% (w/v) PHF exhibited the optimum performances. The membrane showed a pure water flux of 6.7 L·m−2·h−1·bar−1 and salt rejections with the order of Na2SO4 (95.6%) > MgSO4 (93.6%) > MgCl2 (89.9%) > NaCl (22.6%) > LiCl (16.3%). The membrane not only presented a separation factor of 13.1 in separating Mg2+/Li+ mixtures, but also demonstrated excellent antifouling ability, which enables membrane regeneration without operation break, suggesting its great potentials in the recovery of Li+ from brine or seawater.