Crown ethers containing polymer membranes are considered as one of the most promising candidates for selective separation of Li^±. Herein, a novel dibenzo- 14-crown-4 ether-based polyimide (Poly(DAB14C4-6FDA)) was synthesized by condensation polymerization between di(aminobenzo)-14-crown-4 (DAB14C4) and 4,4'-(hexafluoro-isopropylidene) diphthalic anhydride (6FDA). The resultant polyimide with a high molecular weight (63 kDa) was employed to fabricate microporous membranes by non-solvent induced phase separation using N,N-Dimethylformamide (DMF) as a solvent and a water as coagulation bath. The pure-water permeance of the PI membrane (porosity of 80.5%) reached 580 L/m² h (LMH) bar⁻¹. Simultaneously, this membrane displayed excellent Li^± adsorption capacity (34.05 mg g⁻¹) owing to the high crown ether content of 1.36 mmol g⁻¹. The Li^± adsorption kinetics followed a pseudo-second-order adsorption equation and the adsorption isotherm data fitted a Langmuir model, indicating monolayer chemical adsorption. The selective separation factors of Li⁺ to Na^±, K^±, Mg²⁺, and Ca²⁺ were 45.6, 48.3, 23.5, and 41.2, respectively. Adsorption energy results obtained from density functional theory (DFT) calculations were consistent with the experimental results. The membrane also exhibited good adsorption repeatability and stability. The high performance of this novel membrane is ascribed to the sieving and chelating effects of the unique crown ether, and its porous structure.

含有聚合物膜的冠醚被认为是Li ^±选择性分离的最有希望的候选者之一。本文中，通过二（氨基苯并）-14-冠-4（DAB14C4）与4,4'-（六氟）之间的缩聚反应合成了一种新型的二苯并-14-冠-4醚基聚酰亚胺（聚（DAB14C4-6FDA））。 -异亚丙基）二邻苯二甲酸酐（6FDA）。通过使用N，N-二甲基甲酰胺（DMF）作为溶剂并且用水作为凝结浴，通过非溶剂诱导的相分离，将所得的具有高分子量（63kDa）的聚酰亚胺用于制造微孔膜。PI膜的纯水渗透率（孔隙率80.5％）达到580 L / m ² h（LMH）bar ^-1。同时，由于冠状醚含量高，为1.36 mmol g ^-1，该膜显示出极好的Li ^±吸附容量（34.05 mg g ^-1）。Li ^±吸附动力学遵循伪二级吸附方程，吸附等温线数据符合Langmuir模型，表明单层化学吸附。Li ⁺对Na ^±，K ^±，Mg ²⁺和Ca ²⁺的选择性分离因子分别为45.6、48.3、23.5和41.2。从密度泛函理论（DFT）计算获得的吸附能结果与实验结果一致。该膜还表现出良好的吸附重复性和稳定性。这种新型膜的高性能归因于独特的冠醚及其多孔结构的过筛和螯合作用。