Data underlying research for Effect of flow attack angle on spacer-induced electrokinetics in electrodialysis

Spacer geometry plays an important role in membrane separation processes. In electrodialysis, spacer geometry affects not only the pressure-driven flow but can also possibly influence the local electric-field profile and with that the induced electro-osmotic flow by the spacer. We previously demonstrated that using polyelectrolyte-coated spacers gave higher ionic currents for the same driving force, underscoring the additional electro-osmotic mixing from using spacers with charged surfaces. In this study, we expand this work to check the effect of electro-osmotic mixing in combination with spacers having different flow attack angles. We have compared, experimentally, the performance of ED using surface-charged spacers with three different flow attack angles. Our results showed that the spacers with 45$\degree$ flow attack angle outperformed the spacers with 30$\degree$ and 90$\degree$ flow attack angle when using uncoated spacers for certain applied voltage (3 to 8V). On the other hand, an improved effect of a charged coating was mostly observed for the spacer with a 45$\degree$ flow attack angle.

隔网（spacer）的几何结构在膜分离过程中具有重要作用。在电渗析（electrodialysis）中，隔网的几何结构不仅会影响压力驱动流，还可能改变局部电场分布，进而影响隔网诱导的电渗流（electro-osmotic flow）。我们此前的研究表明，在相同驱动力条件下，采用聚电解质涂层隔网（polyelectrolyte-coated spacers）可获得更高的离子电流，这凸显了带电荷表面隔网所带来的额外电渗混合效应。本研究拓展了此前的工作，探究不同流动攻角（flow attack angle）的隔网与电渗混合效应的协同影响。本研究通过实验对比了三种不同流动攻角的带表面电荷隔网应用于电渗析（electrodialysis, ED）时的性能表现。实验结果显示，在施加电压为3~8V的特定工况下，流动攻角为45°的未涂层隔网性能优于30°和90°的隔网。另一方面，带电荷涂层的增效作用在流动攻角为45°的隔网上表现最为显著。