Junwei Zhang, Amit N. Shocron, Victoria Meola, Camille Violet, Zhongren Jiao, Paloma I. Lenz, Yanghua Duan, Ruoyu Wang, Arpita Iddya and Menachem Elimelech*,
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引用次数: 0
Abstract
Ion-exchange membranes (IEMs) are critical to electrochemical ion-separation technologies for environmental and energy applications. Although advancements in separation performance have been frequently reported, significant challenges in evaluating mixed-salt IEM performance under electro-driven conditions remain largely overlooked. Here, we present a new method for the rapid and standardized characterization of ion transport properties for IEMs in mixed-salt systems. Using a modified Goldman-Hodgkin-Katz equation, we demonstrate that individual ion permeability can be obtained from IEM conductance measurements with mixed-salt linear sweep voltammetry experiments. Under low-current conditions, the ion permeability ratio can be converted into different metrics for quantification of ion–ion selectivity including current-based and flux-based selectivity. Our findings also reveal substantial differences between ion transport properties of IEMs under single-salt and mixed-salt conditions, highlighting the critical role of competing ions in transport experiments. Overall, this new approach provides an efficient framework to evaluate IEM performance in environmentally relevant conditions, facilitating cross-membrane performance comparison and establishing the foundation to elucidate the structure-property-performance relationships for IEMs in mixed-salt systems.
期刊介绍:
Environmental Science & Technology Letters serves as an international forum for brief communications on experimental or theoretical results of exceptional timeliness in all aspects of environmental science, both pure and applied. Published as soon as accepted, these communications are summarized in monthly issues. Additionally, the journal features short reviews on emerging topics in environmental science and technology.