度梯度对阴离子交换膜表面电流的影响
Qingpu Wang1, Jaehun Chun2, Chinmayee V Subban1,3
1Energy and Environment Directorate, Pacific Northwest National Laboratory, Seattle, Washington 98109, United States.
Langmuir : the ACS journal of surfaces and colloids
|January 5, 2024
概括
通过阴离子交换膜的度梯度显著影响电透析中的电流. 该研究发现,当电场对抗离子度梯度时,电流会增强,从而影响分离过程.
科学领域:
- 电化学 电化学 电化学
- 化学工程是化学工程的重要组成部分.
- 材料科学 材料科学 材料科学
背景情况:
- 电透析等基于膜的系统对于海水淡化和工业分离至关重要.
- 在电透析中,超限电流会因膜接口的离子耗尽而诱导电流.
- 离子度梯度对功能电透析系统内的电流对流的影响在很大程度上是未知的.
研究的目的:
- 为了研究离子度梯度在阴离子交换膜上对电流的影响.
- 为了确定电场与或对抗度梯度的对齐如何影响电流.
- 量化这些梯度对枯竭边界层厚度的影响.
主要方法:
- 实验使用了一种阴离子交换膜 (Nafion),两侧都有不同度 (0.1-100毫米) 的同流的NaCl溶液.
- 使用罗达胺6G光染料可视化了电流传递.
- 从光图像中获得度概况,以测量耗尽边界层厚度 (d_BL).
主要成果:
- 在较高的流速下观察到较小的耗尽边界层厚度 (d_BL),不论度梯度如何.
- 发现当应用的电场与离子度梯度的方向相反时,电流会增强.
- 该研究在各种条件下系统测量了d_BL,提供了对梯度影响的定量数据.
结论:
- 通过阴离子交换膜的离子度梯度显著调节电透析中的电传递现象.
- 电场相对于度梯度的方向是增强电流的关键因素.
- 了解这些影响对于优化隔离和海水淡化应用中的电透析性能至关重要.
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