University of Chemistry and Technology Prague, Department of Chemical Engineering, Technická 3, Prague 16628, Czech Republic.
University of West Bohemia, New Technologies-Research Centre, Univerzitní 8, Pilsen 30614, Czech Republic.
Int J Mol Sci. 2019 Jul 22;20(14):3579. doi: 10.3390/ijms20143579.
Electrodialysis and electrodeionization are separation processes whose performance depends on the quality and properties of ion-exchange membranes. One of the features that largely affects these properties is heterogeneity of the membranes both on the macroscopic and microscopic level. Macroscopic heterogeneity is an intrinsic property of heterogeneous ion-exchange membranes. In these membranes, the functional ion-exchange component is dispersed in a non-conductive binder. The functional component is finely ground ion-exchange resin particles. The understanding of the effect of structure on the heterogeneous membrane properties and behavior is thus of utmost importance since it does not only affect the actual performance but also the cost and therefore competitiveness of the aforementioned separation processes. Here we study the electrokinetic behavior of cation-exchange resin particle systems with well-defined geometrical structure. This approach can be understood as a bottom up approach regarding the membrane preparation. We prepare a structured cation-exchange membrane by using its fundamental component, which is the ion exchange resin. We then perform an experimental study with four different experimental systems in which the number of used cation-exchange particles changes from 1 to 4. These systems are studied by means of basic electrochemical characterization measurements, such as measurement of current-voltage curves and direct optical observation of phenomena that occur at the interface between the ion-exchange system and the adjacent electrolyte. Our work aims at better understanding of the relation between the structure and the membrane properties and of how structure affects electrokinetic behavior of these systems.
电渗析和电极电渗析是两种分离过程，其性能取决于离子交换膜的质量和特性。影响这些特性的一个重要特征是膜在宏观和微观层面上的非均质性。宏观非均质性是异质离子交换膜的固有特性。在这些膜中，功能离子交换组分分散在非导电的粘合剂中。功能组件是精细研磨的离子交换树脂颗粒。因此，了解结构对异质膜性能和行为的影响至关重要，因为它不仅影响实际性能，还影响成本，从而影响上述分离过程的竞争力。在这里，我们研究了具有明确定义几何结构的阳离子交换树脂颗粒体系的电动行为。这种方法可以被理解为膜制备的自下而上的方法。我们使用离子交换树脂作为基本组件来制备结构化阳离子交换膜。然后，我们使用四种不同的实验系统进行了实验研究，其中使用的阳离子交换颗粒的数量从 1 个增加到 4 个。这些系统通过基本电化学特性测量进行研究，例如电流-电压曲线的测量和直接观察在离子交换系统与相邻电解质之间的界面处发生的现象。我们的工作旨在更好地理解结构与膜性能之间的关系，以及结构如何影响这些系统的电动行为。
