Department of Chemistry and Biochemistry, Center for Electrochemistry, The University of Texas at Austin, 1 University Station, A5300, Austin, Texas 78712-0165, USA.
Analyst. 2011 Oct 21;136(20):4134-7. doi: 10.1039/c1an15510e. Epub 2011 Aug 25.
We report a method for removing ions from aqueous solutions without the use of a membrane. The approach, which we call bipolar electrode depletion (BED), is based on the formation of an asymmetric electric field profile in a microchannel containing a bipolar electrode (BPE). The asymmetric field arises from local increases in conductivity caused by faradaic reactions at the BPE. We show how the asymmetric field can be used to deplete anions from a microchannel via a combination of electrophoresis and electroosmosis. We also apply this approach to filter an anionic species from a mixture of charged and neutral species being transported through a microchannel via electroosmosis. This technique could be utilized for desalination or filtration of any species possessing a net charge (e.g. heavy-metals, bacteria, proteins, or functionalized-nanoparticles).
我们报告了一种无需使用膜即可从水溶液中去除离子的方法。该方法称为双极电极耗尽（BED），它基于在含有双极电极（BPE）的微通道中形成不对称电场分布。不对称场是由 BPE 上的法拉第反应引起的局部电导率增加引起的。我们展示了如何通过电泳和电渗流的组合，利用不对称场从微通道中耗尽阴离子。我们还将此方法应用于通过电渗流在微通道中传输的带电和中性物质的混合物中过滤阴离子物质。该技术可用于去除任何带净电荷的物质（例如重金属、细菌、蛋白质或功能化纳米粒子）的脱盐或过滤。
