Dong Huang
(, ), Xiaohui Ge
(, ), Qian Chen
(, ), Simian Fei
(, ), Qiuhua Li
(, ), Liang Ge
(, ), Tongwen Xu
(, )
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引用次数: 0
Abstract
Development of high-performance ion-selective membranes is crucial for achieving efficient ion separation in water treatment and energy storage applications. In this study, we demonstrate the strategic incorporation of acid-base pairs within a polybenzimidazole matrix through controlled sulfonation. By leveraging these intermolecular interactions, we enhance the Li+/Mg2+ selectivity of the membrane. At an optimal sulfonation degree, the SP45 membrane forms a cross-linked structure, featuring contracted ionic clusters and discrete hydrophilic domains with limited interconnectivity. This unique microstructure imposes significantly higher energy barriers for the transmembrane transport of Mg2+, thereby endowing the SP45 membrane with exceptional perm-selectivity of 48.1 at a current density of 2 mA cm−2. Cycling stability tests reveal that the Li+/Mg2+ selectivity degradation remains below 10% across multiple cycles in diverse mixed-salt systems. In practical brine ion distillation tests, we achieved a separation factor of exceeding 60,000 between Li+ and Mg2+ utilizing a 4-stage ion-distillation device equipped with the prepared SP45 membranes. This work provides fundamental insights into ion transport regulation through molecular-level acid-base pairs engineering, opening new avenues for advanced ion-selective separation membranes.
高性能离子选择膜的开发对于实现水处理和储能应用中的高效离子分离至关重要。在这项研究中,我们证明了通过控制磺化,在多苯并咪唑基质中战略性地结合酸碱对。通过利用这些分子间相互作用,我们增强了膜的Li+/Mg2+选择性。在最佳磺化度下,SP45膜形成交联结构,具有收缩的离子簇和离散的亲水畴,相互连接有限。这种独特的微观结构为Mg2+的跨膜传输施加了更高的能量垒,从而使SP45膜在电流密度为2 mA cm−2时具有48.1的超选择性。循环稳定性测试表明,在不同的混合盐体系中,Li+/Mg2+选择性降解在多次循环中保持在10%以下。在实际卤水离子蒸馏试验中,我们利用配备SP45膜的4级离子蒸馏装置实现了Li+和Mg2+的分离系数超过60,000。这项工作通过分子水平的酸碱对工程为离子转运调控提供了基本的见解,为先进的离子选择性分离膜开辟了新的途径。
期刊介绍:
Science China Materials (SCM) is a globally peer-reviewed journal that covers all facets of materials science. It is supervised by the Chinese Academy of Sciences and co-sponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China. The journal is jointly published monthly in both printed and electronic forms by Science China Press and Springer. The aim of SCM is to encourage communication of high-quality, innovative research results at the cutting-edge interface of materials science with chemistry, physics, biology, and engineering. It focuses on breakthroughs from around the world and aims to become a world-leading academic journal for materials science.