Ion selective separations are becoming increasingly important in many water and energy applications. Ion exchange membranes could address these separation challenges, but advanced understanding of the structure-property relationships that connect polymer chemistry and membrane morphology to selectivity properties is needed. Membrane-based ion separations can be driven by concentration or electric field driving forces, and selectivity is generally defined as counter-ion to counter-ion selectivity or counter-ion to co-ion selectivity. Characterization techniques depend on the definition of selectivity of interest. This review discusses those definitions of selectivity and the methods used to characterize ion selectivity in membranes. Additionally, need for additional data, opportunities for high throughput analysis, and opportunities for connecting molecular simulations with experimental data are discussed.

离子选择性分离在许多水和能源应用中变得越来越重要。离子交换膜可以解决这些分离难题，但是需要对将聚合物化学和膜形态与选择性性质联系起来的结构-性质关系的深入了解。可以通过浓度或电场驱动力来驱动基于膜的离子分离，并且选择性通常定义为相对于抗衡离子选择性的抗衡离子或相对于共聚离子选择性的抗衡离子。表征技术取决于目标选择性的定义。这篇综述讨论了选择性的定义以及表征膜中离子选择性的方法。此外，还需要其他数据，进行高通量分析的机会，