Yifan Zhao , Yang Xiao , Yunqiao Ma , Wenlai Xu , Min Zhong , Ju Yang , Bo Xing , Ziqiang Yin
{"title":"电渗析过程中分离Co2+/Mg2+的冠醚石墨烯膜的分子洞察","authors":"Yifan Zhao , Yang Xiao , Yunqiao Ma , Wenlai Xu , Min Zhong , Ju Yang , Bo Xing , Ziqiang Yin","doi":"10.1016/j.memsci.2025.124710","DOIUrl":null,"url":null,"abstract":"<div><div>Functionalized crown ether modified graphene membranes have exhibited promising capability for the separation of ions. In this study, graphene membranes embedded with crown ether nanopores, namely 18-crown-6-ether (CE18) and 24-crown-8-ether (CE24) were compared for their separation efficiency of Co<sup>2+</sup>/Mg<sup>2+</sup> using molecular dynamics simulation. The separation performance of the CE18 membrane was superior to that of the CE24 membrane, which was attributed to the selective adsorption of membrane to the divalent ions, combined with the dehydration effect. The CE18 membrane had stronger adsorption to Co<sup>2+</sup> compared to Mg<sup>2+</sup>, leading to greater separation ratio. In contrast, the adsorption of the CE24 membrane with both divalent ions was an order of magnitude lower than CE18, and resulted in poor separation efficiency. Smaller pore size of CE18 membranes forced the divalent ions to strip more hydrated water molecules during the transmembrane process, while the dehydration energy of Co<sup>2+</sup> to lose each water molecule was lower than that of Mg<sup>2+</sup>. The combined effects of dehydration number and free energy improved the ion selectivity of the CE18 membrane, whereas the CE24 membrane was less preferable for the separation of Co<sup>2+</sup> and Mg<sup>2+</sup>. The adsorption between the CE groups and the divalent ions advanced the ion flux and selectivity of the CE18 membrane, but it was insufficient to compensate the energy needed for dehydration. This study elucidated the structure-energy-function relationship of crown ether membranes for the separation of Co<sup>2+</sup> and Mg<sup>2+</sup> on the molecular scale, and shed some light for the design of high-performance ion exchange membranes.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"736 ","pages":"Article 124710"},"PeriodicalIF":9.0000,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Molecular insight into crown ether graphene membranes for the separation of Co2+/Mg2+ in electrodialysis processes\",\"authors\":\"Yifan Zhao , Yang Xiao , Yunqiao Ma , Wenlai Xu , Min Zhong , Ju Yang , Bo Xing , Ziqiang Yin\",\"doi\":\"10.1016/j.memsci.2025.124710\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Functionalized crown ether modified graphene membranes have exhibited promising capability for the separation of ions. In this study, graphene membranes embedded with crown ether nanopores, namely 18-crown-6-ether (CE18) and 24-crown-8-ether (CE24) were compared for their separation efficiency of Co<sup>2+</sup>/Mg<sup>2+</sup> using molecular dynamics simulation. The separation performance of the CE18 membrane was superior to that of the CE24 membrane, which was attributed to the selective adsorption of membrane to the divalent ions, combined with the dehydration effect. The CE18 membrane had stronger adsorption to Co<sup>2+</sup> compared to Mg<sup>2+</sup>, leading to greater separation ratio. In contrast, the adsorption of the CE24 membrane with both divalent ions was an order of magnitude lower than CE18, and resulted in poor separation efficiency. Smaller pore size of CE18 membranes forced the divalent ions to strip more hydrated water molecules during the transmembrane process, while the dehydration energy of Co<sup>2+</sup> to lose each water molecule was lower than that of Mg<sup>2+</sup>. The combined effects of dehydration number and free energy improved the ion selectivity of the CE18 membrane, whereas the CE24 membrane was less preferable for the separation of Co<sup>2+</sup> and Mg<sup>2+</sup>. The adsorption between the CE groups and the divalent ions advanced the ion flux and selectivity of the CE18 membrane, but it was insufficient to compensate the energy needed for dehydration. This study elucidated the structure-energy-function relationship of crown ether membranes for the separation of Co<sup>2+</sup> and Mg<sup>2+</sup> on the molecular scale, and shed some light for the design of high-performance ion exchange membranes.</div></div>\",\"PeriodicalId\":368,\"journal\":{\"name\":\"Journal of Membrane Science\",\"volume\":\"736 \",\"pages\":\"Article 124710\"},\"PeriodicalIF\":9.0000,\"publicationDate\":\"2025-09-15\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Membrane Science\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0376738825010233\",\"RegionNum\":1,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ENGINEERING, CHEMICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Membrane Science","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0376738825010233","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}
Molecular insight into crown ether graphene membranes for the separation of Co2+/Mg2+ in electrodialysis processes
Functionalized crown ether modified graphene membranes have exhibited promising capability for the separation of ions. In this study, graphene membranes embedded with crown ether nanopores, namely 18-crown-6-ether (CE18) and 24-crown-8-ether (CE24) were compared for their separation efficiency of Co2+/Mg2+ using molecular dynamics simulation. The separation performance of the CE18 membrane was superior to that of the CE24 membrane, which was attributed to the selective adsorption of membrane to the divalent ions, combined with the dehydration effect. The CE18 membrane had stronger adsorption to Co2+ compared to Mg2+, leading to greater separation ratio. In contrast, the adsorption of the CE24 membrane with both divalent ions was an order of magnitude lower than CE18, and resulted in poor separation efficiency. Smaller pore size of CE18 membranes forced the divalent ions to strip more hydrated water molecules during the transmembrane process, while the dehydration energy of Co2+ to lose each water molecule was lower than that of Mg2+. The combined effects of dehydration number and free energy improved the ion selectivity of the CE18 membrane, whereas the CE24 membrane was less preferable for the separation of Co2+ and Mg2+. The adsorption between the CE groups and the divalent ions advanced the ion flux and selectivity of the CE18 membrane, but it was insufficient to compensate the energy needed for dehydration. This study elucidated the structure-energy-function relationship of crown ether membranes for the separation of Co2+ and Mg2+ on the molecular scale, and shed some light for the design of high-performance ion exchange membranes.
期刊介绍:
The Journal of Membrane Science is a publication that focuses on membrane systems and is aimed at academic and industrial chemists, chemical engineers, materials scientists, and membranologists. It publishes original research and reviews on various aspects of membrane transport, membrane formation/structure, fouling, module/process design, and processes/applications. The journal primarily focuses on the structure, function, and performance of non-biological membranes but also includes papers that relate to biological membranes. The Journal of Membrane Science publishes Full Text Papers, State-of-the-Art Reviews, Letters to the Editor, and Perspectives.